SECTION 601 CONCRETE
601.01 DESCRIPTION. Use concrete consisting of a mixture of cement, fine aggregate,
coarse aggregate, and water, with admixtures as specified, combined in the proportions and mixed to the consistency specified, when forming or casting to dimensions specified in the Plans or as the Engineer directs. Provide the materials, material proportions, equipment, and construction methods necessary to ensure that the concrete produced conforms to the Contract. Structural concrete is concrete fo r structures such as bridges, culverts, and retaining walls and other items detailed as structures in contract documents. Non-structural concrete is all other concrete.
601.02 Materials and Equipment.
601.02.01 Steel Reinforcement. Conform to Section 811.
601.02.02 Cement. Conform to Section 801. Use Type I cement. The Department
will allow the use of Type IP( ≤20), Type IS( ≤30), Type IL(5-15), Type II, Type III, and Type V when the Engineer approves. The Engineer will condition his approval upon satisfactory means of storage and handling to ensure the ready identification of these cements when used in portions of the work. . If unsatisfactory test results are obtained using Type IP( ≤20), Type IS( ≤30), Type IL, Type II, or Type III, or Type V cement complete the work using Type I cement. Do not intermix cement types in any structural unit except when finishing with Type I. Discontinue the use of Type V cement used for the purpose of sulfate resistance if unsatisfactory results are obtained. Provide a new mix design addressing sulfate exposure shall be submitted for approval.
601.02.03 Admixtures. Conform to Section 802. Use air-entraining and water
reducing admixtures in all classes of concrete. Water reducing admixtures are not required when slip forming is used for concrete placement. Use other admixtures when the Engineer directs or approves.
601.02.04 Water. Conform to Section 803.
601.02.05 Fine Aggregate. Conform to Section 804.
601.02.06 Coarse Aggregate. Conform to Section 805.
601.02.07 Joint Materials. Conform to Section 807.
601.02.08 Structural Steel. Conform to Section 812.
601.02.09 Miscellaneous Metals. Conform to Section 813.
601.02.10 Concrete Curing Materials. Conform to Section 823.
601.02.11 Masonry Coating. Conform to Section 828.
601.02.12 Mineral Admixtures. Conform to Section 844.
601.02.13 Forms. Provide forms that are mortar tight, true to the dimensions, lines,
and grades of the structure, and of sufficient strength to prevent appreciable deflection during placing concrete.
A.Form Panels. Form panels are continuous sections of form facing material unbroken by joint marks, against which concrete is placed. For exposed surfaces, use form panels of plywood conforming to U.S. Product Standard PS-1 for 601-1 Exterior B-B (Concrete Form) Class I plywood or any material other than plywood that will produce an equivalent smooth uniform concrete surface.
B.Plywood Forms. Ensure that plywood forms are at least 3/4 inch thick.
C.Plastic Forms. Conform to the manufacturer’s specifications.
D.Plastic Lined Forms. Conform to the manufacturer’s specifications.
E.Metal Forms. Use metal forms of such thickness that the forms will remain true to shape. Do not use metal forms that do not present a smooth surface or line up properly.
F.Stay-In-Place Metal Forms. Conform to the following requirements:
1.Forms and Supports. Fabricate permanent steel bridge deck forms and supports from steel conforming to ASTM A 653 , Grades A through E, and having a zinc coating class of G 165 according to ASTM A 924. Use forms having a minimum thickness of 22 gage.
2.Fastener Hardware. For miscellaneous fastener hardware (bolts, nuts, metal screws, and washers), provide common stock hardware items with a zinc coating equal to or better than that required by ASTM A 153.
3.Coarse Aggregate. Conform to the requirements of Section 805.04.01 for all coarse aggregate used in concrete for bridge decks and barrier walls when using permanent steel bridge deck forms.
4.Precast Beam Hardware. Provide all deck and overhang support hardware that is cast into precast beam tops with a zinc or epoxy coating of a commercial quality grade.
5.Anchor Legs. To anchor angle weld tabs , use straight anchor legs containing a hole having a 1 1/8-inch minimum diameter. If necessary, incline the anchor leg to vertical.
6.Tack Welding. Certified welders are not required for installation of stay-in- place metal forms.
G.Plank Forms. Use plank forms having a minimum nominal thickness of 1 1/2 inches.
H.Form Oil. Provide a commercial quality form oil or other equivalent coating that allows ready release of the forms and does not discolor the concrete or is detrimental to masonry coating.
I.Chamfer Strips. Only use chamfer strips that are no less than 3/4 by 3/4 inch.
601.02.14 Scales. For weighing water, aggregates, cement, and mineral admixtures,
provide either beam, springless dial, or electronic load cell type scales, designed as an integral unit of the batching plant. When checked under static loads, maintain the accuracy of the scales to within 0.5 percent of the net load on the scales. The net load on the scales is the total weight of the actual test weights used in the accuracy determination. Use enough actual test weights to at least equal the weight necessary to check the cement scales to the net load required for a normal size batch. The Department will allow the use of aggregates in combination with test weights to obtain th e accuracy determination of aggregate scales in the higher ranges. Provide dial scales having a minimum of 1,000 graduations with a clear interval between graduation marks of 0.03 inch or more. Provide beam scales having a graduation inte rval not greater than 0.1 percent of the scale capacity with a clear interval of 0.03 inch or more. Provide scales that are sensitive enough to discern movement due to the addition to the scales of a weight equal to 0.1 percent of the scale capacity under load when the scales are not connected for automatic operation, or equal to 0.2 percent when the scales are connected for automatic operation. Equip each beam scale with an auxiliary dial or “telltale” that will indicate to the operator that the required load in the hopper is being approached. The device shall show a minimum of 4 percent of the net rated capacity of the largest beam for underweight and 3 percent for overweight. Ensure that the indicator registers any movement of the beam. 601-2 Provide dial scales with suitable markers capable of being set to indicate the correct position of the dial indicator for predetermined lo ads. Enclose the dial in a glass-faced case for protection against dust. Ensure that all weighing and indicating devices are in full view of and readable by the operator while charging the hopper, and provide the operator with convenient access to all controls. Have all scales inspected and certified before use and whenever the Engineer may deem necessary to confirm the accuracy of the scales. Ensure that an inspection of the scales has been made within the preceding 6 months at any time a plant is supplying concrete to a Department construction project. Have a re presentative of a commercial scales company certified by the Division of Weights and Measures inspect and certify the scales. After the inspection and certification, only make adjustments or changes in the weighing mechanism at the direction of the Engineer. Keep all exposed fulcrums, clevises, and similar working parts of the scales clean at all times. Furnish all weights and other equipment necessary for testing and calibrating the scales.
601.02.15 Batching Plant Equipment. Ensure that the plant conforms to all safety,
health, and sanitation requirements specified in Subsection 107.01.01. Supply the batching plant with bins, weighing hoppers, and scales for the fine aggregate, each size of coarse aggregate, bulk cement, and mineral admixtures. The Department will allow weighing of cementitious material cumulatively. For the bulk cement, provide scales separate and distinct from those used for aggregate. Install and maintain the batching plant in a manner to provide accurate operations at all times. Only use weatherproof equipment for unloading cement, and protect the storage, weighing, and batching equipment for cement from the weather at all times. Provide bins with separate compartments of sufficient capacity for each size of fine and coarse aggregate, and for bulk cement. Design each compartment to discharge efficiently and freely into the weighing hopper. Provide a means of control so that when the quantity desired is being approached, the material may be added slowly and shut off with precision. Use freely suspended weighing hoppers that do not affect the free movement of the weighing mechanism. Enclose the cement weigh hopper to prevent the loss of cement during weighing, and provide it with an approved device to transfer the cement to the batch trucks or the mixer. Construct all hoppers to eliminate leakage and the accumulation of tare materials, and to discharge completely. Provide any hopper that does not discharge satisfactorily with a vibrator having the frequency and power necessary to affect complete discharge.
601.02.16 Mixers.
A.Batch Mixer. Furnish a batch mixer of an approved size and type specified to positively ensure uniform distribution of materials throughout the mass, and to ensure discharge of the entire batch without segregation. Do not use any mixers having a rated capacity of less than one bag batch. Equip the mixer with adequate water storage and a device for accurately measuring and automatically controlling water discharge into each batch. Provide a mechanical device to control time of mixing for each batch and to automatically prevent discharge of the mixture until materials have been mixed for the specified time. Equip the mixer with a mechanical means for preventing addition of aggregates after mixing has started.
B.Continuous Mixer. Furnish a continuous mixer of an approved size and type specified to ensure uniform distribution of materials throughout the mass and to ensure discharge of the entire batch without segregation. Equip continuous type mixers to fix the proportions of admixture, cement, and fine and coarse aggregates by calibration according to KM 64-312 (ASTM C685). Provide devices to indicate the proportions of all components being incorporated into the mixture. Equip the water supply portion of the mixer with a readily accessible cumulative type meter which can be read to the nearest 0.1 gallon. Ensure that the meter is of 601-3 sufficient size to allow for easy reading. Calibrate the continuous type mixer to the satisfaction of the Engineer before starting work. Recalibrate the mixer thereafter at least once during each 50 cubic yards of production when yield checks indicate recalibration is necessary, and at any other times the Engineer deems necessary.
C.Truck Mixer. Furnish a truck mixer of an approved revolving drum or revolving blade type, constructed to produce a thoroughly mixed concrete mass with a uniform distribution of materials throughout. Keep the interior of the mixer drums free from hardened concrete. Equip the truck mixer with a discharge mechanism which will ensure discharging of the mixed concrete without segregation. When the Engineer deems it necessary, provide baffle plates in the chute to avoid segregation in the concrete placed in the work. Make satisfactory repairs to any truck mixers that will not discharge concrete within the specified slump and air content ranges before using them. Attach to each truck mixer a metal plate stating the manufacturer’s capacities in terms of volume of mixed concrete for the various uses the equipment is applicable and the manufacturer’s recommended speeds of rotation for mixing and agitation. For the mixer drum, apply the rates of rotation used for mixing and agitation as designated on the metal plate by the manufacturer of the equipment. Do not allow the mixer drum to lose any water or concrete during charging, mixing, and agitation, or during transportation. Equip the truck mixer with an automatic revolution counter that allows reading of the count at the plant and at the destination. Do not use trucks equipped with defective revolution counters. Keep the interior of the mixer drums free from hardened concrete. Equip tanks containing mixing water on all trucks with a device for accurately determining the quantity of water added at the job site. Conduct annual tests to evaluate capability of the truck mixer to produce a uniform mixture according to KM 64-311. The Department will perform random checks of the tests.
D.Central Mixer.
1.Drum Type Mixer. Equip each drum type mixer with a batch counter and an approved timing device that automatically locks the discharge mechanism during the mixing period.
2.Pan Type Mixer. Equip each pan type mixer with a batch counter and an approved timing device that automatically locks the discharge mechanism during the mixing period.
601.02.17 Concrete Transfer Equipment. To transfer concrete from truck mixers or
agitators, only use equipment of adequate desi gn and dimension to deposit concrete of the specified slump at the point of placement.
601.02.18 Vibrators. Use a type and design approved by the Engineer that is capable
of transmitting vibration to the concrete at frequencies to adequately consolidate the concrete and, when applicable, not damage the epoxy coating on reinforcing steel.
601.02.19 Tremies. Use tremies consisting of a tube having a diameter of 10 inches
or more, constructed in sections having flange d couplings fitted with water tight gaskets.
601.02.20 Wire Brooms. Use Department approved wire brooms.
601.02.21 Slip Form Machine (Extrusion Machine). Use a self-propelled slip form
machine designed to consolidate and finish the concrete in one pass without damaging or displacing any steel reinforcement, and that finishes the concrete to a smooth, uniformly textured surface conforming to the required cross section with a minimum of hand finishing. 601-4
601.02.22 Curing Compound Sprayer. To apply the membrane forming curing
compound, use a sprayer consisting of a container having a capacity of no less than 5 gallons in which a consistent pressure can be maintained by mechanical means or by a suitable pumping arrangement in order to maintain a consistent pressure at the spray nozzle or nozzles, and to uniformly apply the membrane forming curing compound at the specified rate. Use nozzles designed to deliver a uniform, fine spray and that allow for easy cleaning. Provide a shield or apron to protect the spray from wind. Provide means for cleaning the nozzles as part of the spraying equipment.
601.03 CONSTRUCTION. Conduct a pre-pour meeting whenever the work will involve
placing bridge slab concrete, concrete pumping, or trial batches. The Engineer will facilitate the meeting to discuss items such as timing of truck delivery, target air content and slump of delivered concrete, minimizing air content and slump loss through the pump, sampling location and procedures, and other items as appropriate. Attendance is required by the Contractor, concrete supplier, pump contract or (when pumping is involved), and jobsite inspector. When the plans call for the bridge deck to be placed in phases and a change in sequence is desired, submit a request in writing to the Engineer. Include in the request the proposed sequence, supply rate of concrete delivery, retarder schedule, means of delivery (bucket/pump), and any other details which the Engineer may request. The Department will have the designer evaluate the requested change and determine feasibility. Make no changes without the Engineer’s approval.
601.03 01
Care, Storage, and Handling of Aggregates, Cement, and Mineral Admixtures. Furnish, stock, and handle the fine and coarse aggregates at the job site or at the plant site to maintain uniformity of grading and free moisture contents at the time of batching. The Engineer may direct saturation to continue if necessary. Obtain the Engineer’s permission prior to using materials stockpiled at areas remote from the plant site. The Engineer may revoke permission to use materials remote from the plant site any time it is apparent there is not uniformity of grading and free moisture content. When storing in stockpiles, place each size a ggregate in separate stockpiles sufficiently removed from each other to prevent the intermixing of material at edges of piles. Do not use materials which have become mixed with foreign matter, or fine and coarse aggregates which have become mixed with each other. Build stockpiles in layers not exceeding 3 feet in height. Complete each layer before beginning the next layer. Handle aggregates in a manner that ensures the uniformity of the moisture content for each pour. Do not batch directly from washing plants. When handling by hydraulic methods or when washing is involved, stockpile or use bins to drain all aggregates at least 12 hours before batching. Do not remove aggregates from stockpiles within one foot of the ground line until final cleanup of the work. Protect stored cement from dampness at all times. For cement storage, use weatherproof buildings that have ample space for storing separate shipments readily identified and accessible for sampling. Remove the cement from storage in the order received, as practical, to avoid long storage periods. Handle cement in a manner to prevent loss, wetting, or contamination. When using bulk cement, maintain a clean and clear cement feed to the cement batching bin to maintain the correct batch weight at all times. Furnish to the Engineer daily records of the cement shipments to the job batch plant. The Engineer may not require daily records of cement shipments when using commercial concrete plants. Do not allow the temperature of the cement at the time of its incorporation into the mixture to exceed 170 F. Store and handle fly ash and slag as specified for cement. Provide means, such as double wall separation, to prevent the intermixing of cement with fly ash or slag.
601.03.02 Concrete Producer Responsibilities. Obtain the concrete from producers
that are in compliance with KM 64-323 and on the Department’s List of Approved Materials. If a concrete plant becomes unqua lified during a project and there are no other 601-5 qualified plants in the region, the Department will consider a request to provide a qualified personnel to witness and ensure the producer follows the required specifications. The Department will assess the Contractor a $100 per hour charge for this service. Regardless of quantity, ensure that the all concrete producers comply with the following requirements:
A.General. Design concrete mixtures, and perform quality control and process control testing as needed.
B.Certified Personnel. Employ concrete technicians responsible for the design of the concrete mixtures and for performing quality control and process control testing as necessary. Ensure that the concrete technicians are certified as ACI Level I (Level I) and KCA Level II (Level II).
C.Quality Control. Take full responsibility for the batch weight calculations and quality control of concrete mixtures at th e plant. Ensure that the Level II concrete technician is present when work is in progress and is responsible for inspecting trucks, batch weight calculations, monitoring batching, making mixture adjustments, reviewing the slump, air content, unit weight, temperature, and aggregate tests, all to provide conforming concrete to the project. A Level I concrete technician is responsible for testing production material for slump, entrained air, unit weight and temperatur e of the mixture. Ensure the technician performs all sampling and testing according to the appropriate Kentucky Methods. Ensure that Level II concrete technicians cooperate with the Engineer in making minor adjustments to the mixture proportions within the limits of the specifications that may be desirable due to conditions at the job site.
D.Producer Testing. When producing for state work, have a Qualified Concrete Aggregate Technician or KYTC Qualified Aggregate Technician perform, at a minimum, weekly gradations and minus 200 wash tests and daily moisture contents of coarse and fine aggregate (Fine aggregates will not require a minus 200 wash test). Using the daily moisture contents, adjust the approved mix design accordingly prior to production. Ensure that the Level II concrete technician is present when work is in progress and is responsible for inspecting trucks, batch weight calculations, monitoring batching, making mixture adjustments, reviewing the slump, air content, unit weight, temperature, and aggregate tests, all to provide conforming concrete to the project. 601-6
E.Trip Tickets. Furnish a trip ticket containing the minimum information shown in the table below. Certify that the data on the ticket is correct and that the mixture conforms to the approved mix design. Ensure that the plant manager or a Level II concrete technician signs the ticket. The Department's jobsite inspector will complete all other necessary information on the back of the trip ticket. The trip ticket must be from the original concrete producer and only the original concrete producer is permitted to make mix adjustments.
F.Records. Retain all concrete technician records, test results and batch tickets pertaining to concrete produced for a Department project for at least 3 years after formal acceptance of the project. Make all records available to the Engineer and the Contractor on the project for review upon request.
G.Mix Designs. Design the mixture for each class of concrete specified. Determine the proportions of materials to be used on an absolute volume basis. Establish quantities to yield as nearly practical, the design volume. Before producing any concrete for the project, submit a proposed mixture design to the Engineer and obtain the District Materials Engineer’s or the Central Office Material’s approval. Submit the mix design electronically using the Concrete Mix Design Spreadsheet located on the Division of Materials Website. Spreadsheets require the minimum system requirements: Microsoft Office 2003 Professional (full installation). Consider any load of concrete delivered to the job site that fails to conform to specification requirements to be subject to rejection. The Engineer may allow the addition of water and admixtures at the job site. When the Engineer allows the addition of water or admixtures at the job site, take responsibility for the quantity to be added. Water may only be added to the load as a onetime addition prior to depositing any concrete into the structure or pavement. Do not allow the total water/cement ratio to exceed that listed in the Ingredient Proportions and Requirements for Various Classes of Concrete table. The Engineer may test remixed loads having additional water added to the mix at the job site. The Engineer will retest all loads when air entrainment admixtures are added at the jobsite. All acceptance testing will be performed after all permitted additions have been added and remixed. 601-7
1.New Mixture Designs. Base the proposed mix design on standard Department methods unless the District Materials Engineer or Central Office Materials approves otherwise. Include the following with the submitted design:
a.The class of concrete and 28-day compressive strength.
b.The source, specific gravity, percentage, and quantity of fine and coarse aggregate. The District Materials Engineer or Central Office Materials will provide an average value of the specific gravity and aggregate absorption.
c.The cement producer, type, and pounds of cement per cubic yard.
d.The mineral admixture supplier, type, class, percentage of cement reduction and replacement ratio, and total pounds per cubic yard.
e.The source of water, predicted amount of total water per cubic yard, and the maximum allowable water per cubic yard.
f.The brands and predicted dosages of admixtures per cubic yard. If the concrete mixture is a class that the producer has not previously furnished to a Department project, have the producer provide trial batches of at least 4 cubic yards to demonstrate that the mixture will conform to the requirements for slump, air content, water/cement ratio, and compressive strength. Have the producer make the trial batches using the ingredients, proportions, and equipment (including batching, mixing and delivery time) to be used on this project. A Class A tr ial batch will qualify both Class A and Class P mixes. A Class M trial batch will also qualify as a Class P 24 mix. Have the producer make at least two trial batches conforming to all specified requirements. The two trial batches are to be conducted within a reasonable time frame which may be designated by the Engineer. Central Office Materials will observe all phases of the trial batches. Have the producer submit a report containing mix proportions and test results for slump, air content, water/cement ratio, unit weight, and compressive strength for each trial batch to the Engineer for Central Office Materials review and approval.
2.Approval. The District Materials Engi neer or Central Office Materials will base approval of the mixture design on the following criteria:
a.Provide concrete cylinders molded at the project site to verify that the specified compressive strength will be attained.
b.The quantities of components given for a one cubic yard batch will, on the basis of absolute volumes, produce one cubic yard of concrete mix. Include the volume occupied by entrained air.
c.The cement factor is at least the minimum specified in the Ingredient Proportions and Requirements for Various Classes of Concrete table in Subsection 601.03.03.
d.The water/cement ratio does not exceed the maximum specified in the Ingredient Proportions and Requirements for Various Classes of Concrete table in Subsection 601.03.03.
e.The aggregate sources, the cement supplier, the mineral admixture supplier or producer, and the admixture brands are on the Department’s List of Approved Materials.
f.The trial batches, when required, produce acceptable results. The Engineer or District Materials Engin eer may request trial batches at any time before or during a project.
3.Changes in Approved Mixture Designs. Do not change the source of supply of the mixture ingredients without the Di strict Materials Engineer’s or Central Office Materials written permission. If it is necessary to change the source of aggregates, submit a new design reflecting the new source of aggregate to the Engineer. Upon the District Materials Engineer’s or Central Office Materials written approval, the Department will allow the use of aggregate 601-8 from the new source.
601.03.03 Proportioning and Requirements.
A.Concrete.
1.The Department will determine non-payment, additional construction, or removal and replacement for concrete for which test cylinders indicate low compressive strength and any follow-up investigations indicate inadequate strength. The Department may require some classes to attain the required compressive strength in less than 28 days.
2.When the ambient air temperature while placing slab concrete is 71 F or more, add to the concrete a water-reducing and retarding admixture. The Engineer may require or allow, water-reducing and retarding admixture in slab concrete for ambient air temperatures of less than 71 F. Only use one type of admixture for concrete placed during any individual contiguous pour.
3.The Department will require a compressive strength of 5,000 psi, or greater when specified in the Contract, at or before 28 days for prestressed members.
4.The Engineer will allow slumps less than the minimum provided concrete is workable.
5.The Department will allow the use of JPC pavement mixture for non-structural construction.
6.At the option of the prestressed product fabricator, the Department will allow the slump of Class D or Class D Modified concrete to be increased to a maximum of 8 inches for all items, except products with voids. Fo r products with voids, the slump may be increased to 7 inches. Provide a high range water reducer (Type F or G) in an amount not to exceed the following water/cement ratios: Summer mix designs - 0.39 Spring & Fall mix designs - 0.37 INGREDIENT PROPORTIONS AND REQUIREMENTS FOR VARIOUS CLASSES OF CONCRETE Class of Concrete Approximate Percent Fine to Total Aggregate Maximum Free Water by W/C Ratio(14) 28-Day Compressive Strength (1) Slump (4) Minimum Cement Factor Air (11) Content (lb/lb) (psi) (inches) (lb/yd3) (%) Gravel Stone A(5) 36 40 0.49 3,500 2-5(7) 564 6 2 A Mod 36 40 0.47 3,500 4-7 658 6 2 AA(2) 36 40 0.42 4,000 2-5(12) 620 6 2 B 40 44 0.66 2,500 3-5 451 6 2 D(3) 35 39 0.44 4,000 3-5(6) 639 6 2 D Mod(3) 35 39 0.42 5,000 3-5(6) 733 6 2 M1(8) w/ Type 1 Cement or blended hydraulic cement 36 40 0.33 4,000(9) 7 max. 800 6 2 M2(8) w/ Type III Cement 36 40 0.38 4,000(9) 7 max. 705 6 2 P(5) 35 38 0.49 3,500 ---(13) 564(10) 6 2 601-9 Winter mix designs - 0.34
7.The Department may allow an increase of the slump of Class A concrete to a maximum of 7 inches provided that a high range water reducer (Type F or G) is used and maximum water/cement ratio of 0.46.
8.Use a high range water reducer (Type F or G)
9.The Department will require 3,000 psi compressive strength before opening to traffic and 4,000 psi at 28 days.
10.611 lb/yd3 when using coarse aggregate sizes No. 8, 78, or 9-M.
11.7 2% when using coarse aggregate sizes No. 8, 78, or 9-M.
12.The Department may allow the slump of AA concrete to be increased up to a 7-inch maximum, provided the w/c ratio does not exceed 0.40 and a high range water reducer (Type F or G) is used. Trial Batches will be required if producer has not previously supplied.
13.The Department does not have slump requirements for class P concrete mixes except for the edge slump requirements of Section 501.03.19.
B.Mortar, Grout, Flowable Fill, and Self-Consolidating Concrete. When required, ensure that the air content of mortar or grout is 8 percent 2 percent by volume. Do not allow the quantity of fly ash in mortar or grout to exceed 20 percent of the cement quantity.
1.Mortar. Proportion mortar mix with one part cement or cement with fly ash to 2 parts mortar sand, by volume. Add water in an amount not to exceed a water/cement ratio of 0.48.
2.Grout. Proportion grout with water and one part cement or cement with fly ash to 2 parts mortar sand, by volume. Adjust the water to produce a mixture of a consistency suitable for job conditions.
3.Non-Shrink Grout. Use the non-shrink grout on the Department’s List of Approved Materials. Use an a pproved non-shrink, non-staining grout consisting of either a mixture of hydraulic cement, water, fine aggregate, and an approved non-ferrous expansive admixture, or a packaged commercial product conforming to ASTM C1107. To be placed on the Department’s List of Approved Materials, non-shrink, non-staining grout, must conform to the following requirements:
a.Use an initial set time of at least 45 minutes when tested according to ASTM C953. The Department will allow the use of a set-retarding admixture compatible with the expansive admixture.
b.Use grout that has a minimum 7 day compressive strength of 4,500 psi when tested using applicable portions of ASTM C 109.
c.Use grout that has a minimum durability factor of 85 percent and a maximum expansion of 0.06 percent when tested according to KM 64- 626.
d.Keep the water content of the grout as low as possible for proper grouting and do not exceed a water/cement ratio of 0.44. Do not exceed the manufacturer’s recommendations for water added to commercial products.
e.Ensure that the grout does not contain chlorides or nitrates in excess of 0.03%.
f.Cure grout mixtures by covering with 2 layers of wet burlap or other approved covering so as to keep the grout continuously moist for at least 3 calendar days, except cure commercial mixtures as recommended by the manufacturer.
g.Ensure that commercial products are non-ferrous and approximately match the color of hardened concrete.
h.When preparing non-commercial grout mixture, submit a proposed mix 601-10 design and a sample of the expansive admixture to the Engineer for testing and approval before use.
i.When using packaged commercial grout, provide certified test results from the manufacturer showing the material conforms to ASTM C1107. When the Engineer requests, provide samples of the grout mixture for testing and approval.
4.Latex Grout. Use latex and cement mixture of a paste consistency.
5.Flowable Fill. Use flowable fill consisting of a mixture of cement, sand, fly ash, water, and other materials th e Engineer approves. Contrary to Section 844, do not allow the loss on ignition for Class F fly ash to exceed 12 percent. Ensure that the concrete producer certifies mix proportions for flowable fill as follows:
a.Flowable Fill for Pipe Backfill. Proportion as follows, per cubic yard batch: Cement 30 pounds Fly Ash, Class F 300 pounds Natural Sand (S.S.D.) 3,000 pounds Water (Maximum) 550 pounds
b.Flowable Fill for Bridge End Bent Backfill. Proportion as follows, per cubic yard batch: Cement 100 pounds Fly Ash, Class F or Class C 300 pounds Natural or Crushed Sand (S.S.D.) 2,950 pounds Water (Maximum) 550 pounds Alternate Mixtures for Flowable Fill. The Department may approve other mixtures. The mixtures may include other proportions of the above materials, Class C fly ash, chemical admixtures, or aggregate not conforming to the Standard Specifications. When deviating from the above specified proportions and materials, make and test a trial batch of at least 4 cubic yards to ensure that the mix will have flow and density characteristics suited for the intended use. Use the ingredients, proportions, and equipment intended for the project, including batching, mixing, and delivery. The Department will observe all phases of the trial batching for approval. Ensure the proposed mixture is proportioned to obtain a minimum flow of 8 inches when tested with a 3 by 6 inch open ended cylinder modified flow test and meets applicable strength requirements. Ensure additional requirements, as stated below, for time of bleeding and time to achieve firmness are met when appropriate for application. Submit the proposed mixture proportions and appropriate test results to the Engineer for review and approval. When the mixture is proprietary, comply with Subsection 107.05. The Department will cast, cure, and break test cylinders from the flowable fill trial batch according to ASTM D 4832 using 4x8 cylinders. Prior to completion of the 28 day curing period, transport the test cylinders to the MCL for compressive strength testing. Obtain an average compressive strength of 50 to 100 psi at 28 days for application as pipe backfill or minimum compressive strength of 250 psi at 28 days for application as bridge end bent backfill. For applications requiring early opening to traffic or placement of pavement as soon as possi ble, provide a mixture that conforms to the following general guidelines:
1.Mixture bleeds freely within 10 minutes. 601-11
2.Require the mixture to support a 150-pound person within 3 hours. The Engineer will approve flowable fill, delivered to the project, based on certifications indicating proper proportions for the intended use.
6.Self Consolidating Concrete (SCC). Conform to KM 64-320 with application limited to precast plants.
C.Mixtures Using Type IP( ≤20), IS(≤30), and IL Cement and Mineral Admixtures. The Engineer will not consider any Contract time extension requests for delays due to additional time necessary to attain specified strengths. Seasonal limitations on the use of Type IP cement and fly ash in bridge decks are specified in Subsection 601.03.09 D).
1.Type IP(≤20), IS(≤30), IL Cement. The Department will allow the use when substituted for Type I cement, pound for pound. To produce the necessary workability, strength properties, and expected durability of the concrete, the Department will allow adjustment of the proportioning, air entraining agent, and finishing requirements; and acceptance procedures. Obtain the Engineer’s approval for all such adjustments. Conform to all strength requirements for loading structures or removing falsework before applying loads or removing falsework. If strength requirements are not met, increase the minimum times specified in the Required Time in Calendar Days before Removing Forms and Falsework table in Subsection 601.03.14 and the Required Time in Calendar Days before Applying Significant Loads on Concrete Structures table in Subsection
601.03.15 by 33 percent.
Ensure that the mixture contains the specified amount of entrained air.
2.Mineral Admixtures. The use of fly ash, slag cement, or micosilica in concrete is the Contractor's option. Reduction of the total cement content by a combination of mineral admixtures will be allowed, up to a maximum of 40 percent. When the ability to use slag cement or microsilica has not been demonstrated have the concrete producer provide trial batches in accordance with Subsection 601.03.02 G) 1). Have the producer make the trial batches using the ingredients, proportions, and equipment (including batching, mixing and delivery time) to be used on the project. Furnish all required materials and samples at no cost to the Department.
a.Fly Ash. When added as a separate ingredient, the Department will allow the use of fly ash to reduce the quantity of cement, except do not use fly ash to reduce the quantity of Type IP cement. The Department will allow the use of Class F fly ash to reduce the quantity of cement up to a maximum of 20 percent of the mini mum cement content. For each 1.0 pound of cement reduced, add at least 1.0 pound, but no more than 1.25 pounds, of Class F fly ash. The Department will allow the use of Class C fly ash to reduce the quantity of cement up to a maximum of 30 percent of the minimum cement content. For each 1.0 pound of cement reduced, add 1.0 pound of Class C fly ash. Incorporate and uniformly distribute the fly ash into the mixture using methods and equipment that the Engineer approves. The Department will allow weighing of fly ash cumulatively in the same weigh hopper with the cement, but weigh the cement first. Conform to all strength requirements for loading structures or removing falsework before applying loads or removing falsework. If strength requirements are not met, increase the required times specified 601-12 in the Required Time in Calendar Days Before Removing Forms and Falsework table in Subsection 601.03.14 and the Required Time in Calendar Days Before Applying Significant Loads on Concrete Structures table in Subsection 601.03.15 by 33 percent. To produce the necessary workability, strength properties, and expected durability of the concrete, the Department will allow adjustment of the proportioning, air entraining agent, finishing requirements, and acceptance procedures. Obtain the Engineer’s approval for all such adjustments. Calculate the maximum free water based on the total cementitious material including fly ash. Do not change any of the slump requirements. Ensure that the mixture contains the specified amount of entrained air.
b.Slag Cement. When added as a separate ingredient, use Grade 120 or Grade 100 Slag to reduce the quantity of cement, except do not use slag cement to reduce the quantity of Type IS( ≤30) cement. The Department will allow the use of slag cement to reduce the quantity of cement up to a maximum of 30 percent of the minimum cement content. For every 1.0 pound of cement reduced, add 1.0 pound of slag cement. The combined weight of the cement and slag cement will determine the minimum cement factor and water cement ratio. Due to the lower specific gravity of slag cement, the concrete volume will increase. Unless directed by the Engineer, adjust the increased volume by reducing an equal volume of the fine and coarse aggregate in the mixture. Use Type I cement unless otherwise specified. Use Type II cement only if requested and approved in writing. When additional cements are approved, store and handle the cement so intermixing does not occur. Work done with each cement shall be readily identifiable. If test results are unsatisfactory, complete the work using Type I cement. Use only one brand of cement for each structure unless otherwise permitted by the Engineer. Weigh the cement first when weighing slag cement cumulatively in the same weigh hopper. Incorporate the slag cement into the mixture by methods and equipment that ensure uniform distribution throughout the mixture.
c.Microsilica. When added as a separate ingredient, replace cement with microsilica as a percentage by weight specified elsewhere in the contract. When not specified elsewhere, replace 7 percent. The Department will allow the use of microsilica to reduce the quantity of cement up to a maximum of 10 percent of the minimum cement content. The combined weight of the cement and microsilica will determine the minimum cement factor and water cement ratio. Use a high range water reducer conforming to ASTM C 494, Type F or Type G. Incorporate into the microsilica slurry or add at the time of batching for dry microsilica. Use Type I cement unless otherwise specified. Use Type IS(<30) or Type II cement only if requested and approved in writing. When additional cement types are approved, store and handle the cement so intermixing does not occur. Work done with each cement shall be readily identifiable. If test results are unsatisfactory, complete the work using Type I cement. Use only one brand of cement for each structure unless otherwise permitted by the Engineer. Weigh the cement first when weighing microsilica in the dry or pellet form cumulatively in the same hopper. When the microsilica is in a slurry form, verify the dispenser or other means of measurement to the Engineer’s satisfaction. The percent of microsilica will be considered in the measurement determinations and in the proportioning calculations. 601-13 When the microsilica admixture is in a slurry form, continuously recirculate by pumping. Begin recirculation at least four hours before batching and continue until batching operations cease. When using a truck mixer, limit the mixer charge to 3/4 of its rated capacity, unless the Engineer approves a larger size.
D.Department Tests. The Department will test the work at the minimum frequencies indicated in the Manual of Field Sampling and Testing Practices or as necessary to determine the quality. The Department will perform the tests according to procedures outlined by the applicable Kentucky Method. The Department will cast and test compressive strength specimens according to KM 64-305 and ASTM C 39, respectively. In cas es of failures, the Department will evaluate cylinder results according to KM 64-314 to determine whether in-place investigation may be necessary.
E.Measuring. Conform to the individual ingredient material batching tolerances in Appendix A.
1.Cement. Measure cement by weight, considering one bag equal to 94 pounds, or weigh it in bulk on scales. When the weight of an entire shipment of cement in bags varies more than 2 percent from 94 pounds per bag, weigh the cement in bulk on scales. Do not produce batches from fractional bags, unless the entire quantity of cement is batched by weight as required for handling bulk cement.
2.Aggregates. Measure fine and coarse aggregates by weight, making corrections for moisture content. When the fine and coarse aggregates used contain more than the maximum free water stipulated in the Ingredient Proportions and Requirements for Various Classes of Concrete table in Subsection 601.03.03, increase the cement content according to the concrete proportioning requirements, and ensure that the maximum water/cement ratio is not exceeded.
3.Water. Measure water either by weight or by volume. Use an approved visible measuring device for measuring water. Use only water meter systems and other approved volumetric systems that can accurately deliver into the mixer, to within 1 percent of the required amount of water per batch and are arranged to automatically stop flow of water when the required quantity has been delivered into the mixer. When the water measuring device fails to deliver the quantity of water discharged into the mixer within the limits specified, suspend operation of the mixer until making repairs and proper adjustments. Assume water weighs 8.34 pounds per gallon. Each time the scales are checked, check, or obtain an approved scale company to check, water meter systems for accuracy in the presence of the Engineer. Ensure that all calculations are included in the scale company’s report. Withhold a portion of the water until the last part of the batching process to wash any cement that is sticking to the sides of the mixer into the mix.
4.Measuring Admixtures. Introduce liquid admixtures into the concrete batch along with, or as part of, the mixing water. Keep air-entraining admixtures completely separate from all other admixtures until introduction into the batch. Maintain and equip dispensing equipment to ensure no chlorides are introduced into any Department mix. Use approved dispensing equipment with a meter, gauge, or scale that can accurately be pre-set for the needed amount of admixture and can consistently deliver quantities of admixture to successive batches at any setting with satisfactory accuracy. The dispensing equipment must be visible to the batch operator. Ensure admixture dispensers are inspected, calibrated and certified every 6 months. The Department may allow admixtures to be added, to the truck, at the 601-14 project site provided the Engineer’s approval is obtained first. Air detraining admixtures are not to be permitted
601.03.04 Classes and Primary Uses. Use the following classes of concrete in the
types of construction designated.
A.Class A. All reinforced concrete abutments below top of caps including pedestals, retaining walls, box culverts, pipe culvert headwalls, nonstructural concrete, and all items for which the concrete class is not specified.
B.Class A Modified. All concrete deposited under water.
C.Class AA. All reinforced concrete in bridge substructures and superstructures above the tops of caps, excluding pedestals.
D.Class B. Gravity retaining walls, and all non-reinforced concrete deposited as fill for cavities or voids and mass footings.
E.Class D. Prestressed I beams, cast-in-place piles, and precast piles.
F.Class D Modified. Prestressed box, slab, and I-beams; and prestressed concrete piles.
G.Class M1. High early strength for bridge joint repair and full or partial depth bridge deck patching. (Type 1 cement or blended hydraulic cement)
H.Class M2. High early strength for bridge joint repair and full or partial depth bridge deck patching. (Type III cement)
I.Class P. JPC pavement.
J.Mortar. Concrete pipe joint seals, leveling drainage structure flowlines, and filling around inlets or outlets of drainage structures.
K.Flowable Fill. Backfill for pipe and bridge end bents
L.Grout. Patching, filling spalled areas, or ot her uses specified in the Contract.
M.Latex Grout. Bond coat between existing bridge surface and new overlays; and joint sealing for centerline and other construction joints and minor cracking on overlays.
N.Non-Shrink Grout. Bonding and sealing for post-tensioning, tie-back rods and bolts, and box beams.
O.Self-Consolidating Concrete (SCC). Precast Units.
P.Dry Cast. Precast units.
601.03.05 Admixtures. For all classes of concrete, add at least a water-reducing
admixture. Water reducing admixtures are not required when slip forming is used for concrete placement. The Department will allow the use of other admixtures when specified or approved by Engineer. The Department will allow admixtures according to the Ingredient Proportions and Requirements for Various Classes of Concrete table in Subsection 601.03.03. Follow the manufacturer’s recommendations in determining the quantity of admixture to use. Ensure that the concrete producer establishes the quantity of air-entraining admixture necessary to produce a mixture having the specified air content for the class of concrete being produced. Add air-entraining admixtures separately from other admixtures, and keep them separate until introducing them into the mixing water or concrete mixture. The Engineer will not require air-entraining of mo rtar or grouts, except when they are exposed to freeze-thaw conditions. Ensure that any type of admixture is uniform in properties throughout its use in the work. Only dispense of admixtures in liquid form unless the Engineer approves prepackaged powdered water reducing admixtures. When using more than one admixture ensure that the admixtures are compatible. When using fly ash, ensure that the concrete producer uses fly ash compatible admixtures. Clearly label admixture containers that indicate the exact brand name and type of admixture. Store products in containers with the correct label. Store admixtures where the liquid temperatures can be maintained between 32 and 110 F. When using water-reducing and retarding ad mixtures provide th e Engineer with manufacturer’s recommendations regarding the quantity of admixture used and expected 601-15 retardation period for the job mixture and conditions.
601.03.06 Slump. The Department will measure the slump of the concrete as
described in KM 64-302. Do not exceed the water/cement ratio, including the free water on the aggregates, according to the Ingredient Proportions and Requirements for Various Classes of Concrete table in Subsection 601.03.03. In general, use a mixture which contains the minimum quantity of water required by these specifications, and ensure that concrete mixtures are such that:
1.mortar clings to the coarse aggregate;
2.concrete is not sufficiently fluid to segregate when transported to the place of deposit;
3.mortar shows no free water when removed from the mixer;
4.concrete, when transported in metal chutes at an angle of 30 degrees with the horizontal, slides rather than flows into place; and
5.upper layers of the hardened concrete show a cement film on the surface but are free from laitance.
601.03.07 Delivery. Mix the concrete in the quantities required for immediate use.
Except for prestressed box beams, do not allow an interval greater than 20 minutes between delivery of batches placed contiguously in the work. When using concrete with a water reducing and retarding admixture, the Engineer will allow a 30-minute intervals between the delivery of batches, except for bridge deck slabs. For prestressed box beams, the Engineer will allow a 45-minute interval for delivery of batches between placement of the bottom slab and the remainder of the box beam when using concrete with a water reducing and retarding admixture. After adding all water, cement, and aggregates to the mixer, deliver and place concrete in its final position within the time limits listed in the following table. Do not use concrete that has developed initial set, that has become segregated, or that has not been delivered within the time limits listed. TIME OF DISCHARGE LIMITS (1) (minutes) Normal Concrete (2) Retarded Concrete (3) Agitated (4) Agitor (5) Non-Agitated Agitated (4) Agitor (5) Non-Agitated 60 45 30 90(6) 60 30
1.All times begin when cement first enters the mixer.
2.Normal concrete is concrete without the addition of a water-reducing and retarding admixture.
3.Retarded concrete is concrete to which a water-reducing and retarding admixture has been added at the Engineer’s direction or approval.
4.Agitated is defined as concrete that has been continuously agitated from the time of initial contact between cement and mixing water to the time of placement at the site of work.
5.An agitor is a truck with paddles.
6.120 minutes for Class B concrete placed in miscellaneous work such as fence post footings. 601-16
601.03.08 Mixing Concrete.
A.General. The Department will allow mixing of concrete at the site of work or the use of ready-mixed methods. Ready-mixed concrete includes central-mixed and truck-mixed concrete. Site mixing includes batch mixing and continuous mixing. The Engineer may allow hand mixing.
B.Site Mixing. Thoroughly mix concrete in a batch mixer or continuous mixer. Maintain the mixer, whether batch or continuous type, free of partially dried or hardened materials at all times. Consistently produce concrete to provide a uniform thoroughly blended mixture within the specified air content and slump limits.
1.Batch Mixing. Mix all concrete for a period of no less than 60 seconds after all materials, including water, are in the mixer. During the period of mixing, operate the drum at the manufacturer’s recommended drum speed. When necessary, continue mixing until all aggregates are thoroughly coated with mortar. Remove the entire contents of the mixer from the drum before adding any materials for the succeeding batch. Deposit materials composing a batch simultaneously into the mixer. Do not operate any mixer above its rated capacity.
2.Continuous Mixing. The Department will allow the use of continuous type mixers for Class A or Class B concrete, except do not use them to place concrete in bridges or box culverts. Notify the Engineer of any proposed changes in the proportioning of any of the ingredients. Maintain the free- moisture content of the fine aggregate within the limits necessary to produce concrete conforming to these specifications. Perform slump tests on mixtures produced by continuous type mixers 4 to 5 minutes after depositing the concrete.
C.Ready-Mixed. When electing to use ready-mixed concrete, prevent delays in delivery and placing concrete. Provide a means of direct voice communication between the inspector at the job site and the inspector at the plant.
1.Truck Mixing. Accurately measure and control the entire quantity of mixing water to within 1 percent accuracy. Mix each batch no less than 70 revolutions at the plant site, at the rate of rotation the manufacturer specifies for a mixing speed. The Department will allow a reduction in mixing to 50 revolutions when the batch is charged so that all ingredients, including water, are uniformly blended during charging to produce a satisfactory mixture. In this case, mix the concrete an additional 10 revolutions at the specified mixing speed at the job site. When the Engineer allows additional water or admixtures at the job site, mix the concrete an additional 30 revolutions at the specified mixing speed after addition. Perform any additional mixing at a lower speed as the mixer manufacturer specifies for agitation, and continuously agitate until discharging the batch. Replace or repair any truck mixer that does not produce a uniform mixture.
2.Central Plant Mixing. When using a central-mixing plant, mix the concrete in an approved drum type mixer or pan type mixer. For drum type mixers having a rated capacity of 2 cubic yards or less, mix for a minimum of 60 seconds. For mixers having capacities greater than 2 cubic yards, mix for a minimum of 90 seconds. The Department will allow a reduction in the minimum mixing time for drum type mixers from 90 to 75 seconds when the concrete ingredients are uniformly blended during the charging of the mixer. In order to attain uniform blending, charge the batch so that the flows of 601-17 water, coarse aggregate, fine aggregat e, and cement are started, continued, and ended simultaneously or nearly simultaneously. For pan type mixers having a rated capacity of 3 cubic yards or less, mix for a minimum of 45 seconds. Increase the mixing time for pan type mixers having rated capacities greater than 3 cubic yards by 15 seconds for each 3 cubic yards, over that allowed for the 3-cubic yard mixer. Any fraction of 3 cubic yards is considered to be 3 cubic yards. The Engineer may increase the minimum mixing time for any type of mixer if the mixer does not produce the desirable quality with respect to uniformity of mixture, slump, and air content, or upon proof by tests that concrete of an undesirable quality with regard to compressive strength would be prevented by additional mixing. Measure the mixing time from the time all cement and aggregates are charged into the mixer until the mixer is ready for discharging. Deliver concrete for use at points other than the central plant site in approved truck mixers. Start agitating immediately after introducing the batch into the mixer and continue without interruption until discharging the batch. Completely discharge each batch before introducing the succeeding batch. The Department will allow the delivery of central-mixed concrete without agitation to a structural unit having a volume not exceeding 10 cubic yards, provided the time of delivery does not exceed the 30-minute limit listed in the Time of Discharge Limits table in Subsection 601.03.07 and the interval between delivery of batches does not exceed 20 minutes.
601.03.09 Placing Concrete.
A.General. Deliver concrete to its final position of placement within the time required for delivery after mixing and within the required time interval between delivery of batches as specified for the method of mixing and handling employed. Moisten forms and reinforcement with water immediately before placing the concrete. Ensure that all equipment used for handling or placing concrete accommodates concrete of the proportions and consistencies as specified. The Engineer will make no adjustments in mixture proportions to accommodate equipment incapable of handling concrete of specified proportions and consistencies. Whenever possible, completely remove water from all foundation excavations before depositing concrete. When it is necessary to deposit concrete under water, place concrete according to the requirements specified. Employ methods and manners of placing concrete that avoid segregation or separation of aggregates or displacement of reinforcement. The Department will allow the use of long chutes, troughs, belts, and pipes for conveying concrete from the mixing plant or point of delivery to the forms only with the Engineer’s written permission. When the Engineer allows such conveyers and the quality of concrete or methods of placing or working it are not satisfactory, discontinue their use and re-equip his plant or conveyance to place concrete in a satisfactory manner. Arrange and use troughs, pipes, or chutes used as aids in placing concrete so that ingredients of the concrete are not sepa rated. Where steep slopes are required, equip the chutes with baffle boards or provide the chutes in short lengths that change the direction of movement. Maintain all chutes, troughs, and pipes clean and free from coating of hardened concrete by thoroughly flushing with water after each run or when out of operation for more than 30 minutes. Discharge water used for flushing clear of in-place concrete. Use troughs, pipes, and chutes that are either metal or metal lined and extend as near as possible to the point of deposit. Do not use aluminum or aluminum alloy troughs, pipes, or chutes that have surface damage or for lengths greater than 20 feet. 601-18 Do not drop concrete in excess of 5 feet without using pipe or tremies, and do not deposit a large quantity at any point and run or work it along the forms. When pumping, equip the delivery pipe with a nozzle, having a restricting device at the discharge end. Maintain the discharge end of the pipe as close to the point of deposit as feasible. Place concrete to entirel y fill but not bulge or distort the forms or to disturb their alignment. Fill each part of the forms by depositing concrete as near its final position as possible, to work the coarser aggregate back from the face, and to force concrete under and around reinforcing bars without displacing them. After concrete has taken its initial set, avoid jarring the forms or placing any strain on ends of projecting reinforcement. Consolidate concrete in all bridges and box culverts with a mechanical vibrator operated within the mass of concrete. Consolidate concrete in all other concrete construction, exclusive of pavement, either by vibration as described herein or with approved spading tools. When vibrating concrete, the Engineer will require spading in addition to vibrating to prevent formation of honeycomb, voids, and air pockets against the forms, except for concrete placed in pavements, bridge slabs, footings, and culvert slabs. Provide vibration of sufficient intensity and duration to cause flow or settlement of the concrete and complete consolidation, but ensure that vibration is not used to cause concrete to flow over long distances in the forms or is unduly prolonged to cause segregation or undesirable laitance at the surface of the lift being consolidated. Use plastic coated vibrators, when necessary, to prevent damage to the epoxy coating of the steel. Provide and use a sufficient number of mechanical vibrators to ensure that cons olidation can be started immediately after concrete has been deposited in the forms. Do not attach the mechanical vibrator to the forms or reinforcing steel or apply to the surface of the concrete. Apply the vibrator to the concrete immediately after depositing the concrete and move it throughout the mass, thoroughly working the concrete around the reinforcement, embedded fixtures, and into angles and corners of the forms. Design forms to provide for requirements of vibration. Place concrete in continuous horizontal layers not exceeding a thickness of one foot, unless otherwise specified for different types of structures. In any given layer, place and consolidate consecutive batches before the preceding batch has taken its initial set. Ensure that each layer of concrete retains a rough surface to secure efficient bonding with the next layer. Consolidate a succeeding layer placed before the underlying layer has set in a manner that will entirely break up and eliminate the tendency to produce a cold joint between layers. Construct the bridge seats comprising the area of that portion of the pier or abutment tops receiving steel bridge bearings to an elevation of 1/8 inch greater than that specified in the Plans for an area in excess of the bearing area occupied by masonry bearing plates. Construct th is excess material for the bearing area with mortar of the same proportions as that in the concrete and cast it monolithic with the pier or abutment. Prevent the coarse aggregate from being placed within 1/4 inch of finished elevation specified in the Plans. Immediately after depositing the mortar, strike the surface off by means of a wooden float. When the concrete has thoroughly hardened, finish it to the true, correct elevation specified in the Plans by tooling and polishing. Test the finished surface with a spirit level, and ensure that there is no variation in excess of 1/32 inch above or below a true level plane. When temporarily discontinuing placing, clean the concrete, after it becomes firm enough to retain its form, of laitance and other objectionable material to a sufficient depth to expose sound concrete. To avoid visible joints as far as possible upon exposed faces, make construction join ts according to Subsection 601.03.10. Regulate the method and manner of placing concrete so as to place all construction joints across regions of low shearing stress and in locations that will be hidden from view the greatest possible extent. Use methods and sequences of placing concrete for various types of concrete bridge construction as specified for 601-19 the particular type of construction involved. Deposit and consolidate concrete to form a compact, dense, and impervious mass of uniform texture having smooth faces on exposed surfaces. When any section of concrete is defective, remove and satisfactorily replace or repair it as directed.
B.Placing Concrete Under Water. Do not expose concrete to the action of water before setting, or deposit it in water, except upon the Engineer’s written permission. Mix all concrete deposited under water in proportions specified for Class A Modified. Place concrete deposited under water in its final position by means of a tremie or by other approved met hods. Do not disturb it after depositing. Provide a sufficient number of tremies or other approved devices to ensure proper distribution of concrete to all portions of the seal. Maintain calm water at the point of deposit. Do not place any concrete in flowing water. Ensure that all form work, such as interlocking sheeting, designed to retain concrete under water is water- tight. Regulate the consistency of the concrete to prevent segregation of materials. Maintain the surface of the concrete as near ly horizontal as practical at all times. To ensure thorough bonding, place each succeeding layer before the preceding layer has taken its initial set. Close the discharge end at the start of work to prevent water from entering the tube. Induce the flow of concrete by slightly raising the tremie, but always keeping the discharge end in the deposited concrete. Stop the flow by lowering the tremie. Provide a continuous flow a nd, unless unavoidable, do not interrupt it until completing the work. The Department will allow dewatering when the concrete is sufficiently strong to withstand hydrostatic pressure, but in no case in less than 3 calendar days after placing, or such additional length of time as the Engineer may direct. Remove all laitance or other unsatisfactory material from the exposed surfaces by scraping, chipping, or other means which will not injure the concrete surface, as the Engineer directs. When it is necessary to use a concrete seal in construction of a foundation, construct it as hereinafter described. A c oncrete seal in a foundation is that volume of concrete placed under water by means of a tremie or other approved means for sealing the entire bottom area of the excavated pit within the cofferdam against hydrostatic pressure, to dewater the excavation and construct the remainder of the foundation in dewatered forms. Use Class A Modified concrete for the seal, and in general make the thickness of the seal course 0.43 times the hydrostatic head exerting pressure on the bottom of the foundati on, or of a thickness as specified in the Plans. Place the corners of the seal to an elevation lower than the remaining surface of the seal course for the purpose of dewatering. In such cases, do not exceed an elevation difference between the corners and the remaining surface of 6 inches.
C.Placing Flowable Fill. To place flowable fill requires a minimum trench width of 6 inches clearance on each side of the pipe. The Engineer will allow standing water to be in the trench when backfilling with flowable fill. Deep trenches may require bleeder trenches or placement in layers to drain excess water. Because certain types of pipe may float, backfill in lifts or anchor the pipe when necessary. Backfilling in lifts is more applicable to long lines of pipe, allowing time for a substantial amount of the water to dissipate before applying the next lift. The Department will allow the use of adequately spaced anchors made of small lumber or metal straps to anchor the pipe. For larger diameter pipe, it may be possible to maintain a surge of flowable fill on top of the pipe to prevent floating. Floating usually does not occur after the level of the backfill is above the springline of the pipe. Ensure that the pipe remains in the correct horizontal position and elevation. Place flowable fill by discharging directly from truck chutes into the trench or place by means of conveyors, buckets or pumps. When pumping, fill the voids 601-20 adequately with solid particles to provide cohesion during the transport through the pump line under pressure to prevent segregation and line blockage. Maintain continuous flow through the pump line to prevent segregation and line blockage. Place the flowable fill from the top of the compacted bedding to the bottom of the pavement structure. Unless th e Engineer directs otherwise, allow a minimum of 2 hours before adding and compacting any material above the flowable fill. To expedite settling and hardening in cool weather, drain or pump the bleed water from the surface or overfill the trench to allow bleed water to flow out. When overfilling, remove all excess material after hardening. The flowable fill will bleed water within 5 to 10 minutes after placement. The release of water by bleeding causes the solid particles to realign and become firm. A delay in bleeding indicates there are too many fines in the mixture or insufficient water. If the maximum water was added, reduce the fly ash quantity in increments of 50 pounds until the mixture bleeds freely. Add approximately 60 pounds of sand to replace each 50-pound increment of fly ash to maintain the original yield. When 2 increment reductions, 100 pounds total, do not promote free bleeding of the mixture, evaluate other possible remedies. The flowable fill is too dry when cracks develop as it flows into place.
D.Weather Limitations and Protection. Designate an employee for the Engineer to contact in case of unexpected situations. The Department reserves the right to discontinue concrete placement when the means of protection or method of placement does not produce satisfactory results. Maintain the temperature of the mixture at or below 90 F during placement. Unless the Engineer determines that safety concerns or other considerations prohibit a shutdown, cease concrete production when the mixture exceeds 90 F until adequate methods are in place to redu ce or maintain the mixture temperature. Ensure that the temperature of the concre te mixture immediately before placing in bridges or box culverts is between 50 and 90 F. When the ambient air temperature is above 90 F, cool the temperature of the forms, reinforcing steel, steel beam flanges, and other surfaces that will come in contact with the mixture to below 90 F by means of a water spray or other approved methods. Allow excess water to drain, or remove it from the forms before placing concrete. Do not place concrete in box culverts or bridges if the ambient temperature exceeds 100 F. Maintain a minimum surface concrete temperature of 45 F for 3 calendar days after placement and at a minimum surface concrete temperature of 40 F for an additional 4 calendar days, unless acceptable cylinder strength is achieved, as determined by the engineer. Do not place concrete during times of th e year that ambient temperatures may be expected to drop below the 45 F or 40 F limits, unless there are adequate provisions at the job site for maintaining concrete at the specified temperature. Do not place concrete in contact with any material coated with frost or having a temperature of 32°F or lower. Submit a written plan detailing the methods to be used for protecting concrete for the Engi neer’s review. When performing cold weather concrete work, provide and install recording thermometers or other approved temperature measuring devices. In cold weather, heat all water and/or aggregate so the temperature of the mixed concrete is no less than 50 F or more than 90 F at the time of placement. To avoid the possibility of flash set when water or aggregate is heated to above 100 F, mix the water and aggregate before adding the cement, and do not exceed a temperature of 90 F for the mixture of water and aggregate when adding the cement. When using artificial heat, provide a means to maintain adequate moisture in the air within the enclosure. Maintain surfaces of all concrete in a moist condition as specified for curing during the entire curing period. When using artificial heat, do not exceed a temperature of 90 F for concrete near the source of heat, and maintain the temperature of concrete remote from the source of heat higher than 601-21 the designated 45 F or 40 F for the time of curing after placement. When using stoves or salamanders, make adequate provisions for fire protection. Assume all risk connected with placing concrete under these conditions, and even with the Engineer’s permission to do the work, take responsibility for proper results. Should concrete placed under such conditions prove unsatisfactory, remove and replace it with satisfactory concrete. Do not use fly ash or Type 1P cement in bridge decks, JPC pavement, JPC base, or JPC shoulders between November 1 and March 1 if the item is to be opened to public traffic and exposed to deicing salts. If the item will remain closed to public traffic until the following spring or later, the Department will allow the use of fly ash or Type 1P cement during this period.
601.03.10 Construction Joints.
A.General Requirements for Structures. When work of placing concrete is delayed until the concrete attains its initial set, deem the point of stopping to be a construction joint. Locate construction joints in the structure as specified in the Contract for the different types of structures; but, when the volume of concrete is too great to be placed without the use of additional construction joints, locate and construct the additional construction joints without impairing the strength or appearance of the structure as the Engin eer approves. Avoid construction joints through paneled wingwalls or other surfaces to be treated architecturally. To avoid visible joints as far as possible upon exposed faces, finish the top surface of concrete adjacent to the forms by smoothing with a mason’s plastering trowel. Where a featheredge might be produced at a construction joint, as in the sloped top surface of a wingwall, use an inset form work to produce a blocked out portion in the preceding layer that produces an edge thickness of 6 inches or more in the succeeding layer. Do not stop or temporarily discontinue work on any section or layer within 18 inches below the top of any face unless details of the work provide for a coping having a thickness less than 18 inches. When the details provide for a coping having a thickness less than 18 inches, the Engineer may allow placement of the construction joint at the underside of the coping. Whenever construction joints are required and in the opinion of the Engineer an insufficient quantity of reinforcement is projecting to secure satisfactory bond, accomplish bonding as specified in B) below.
B.Bonding Construction Joints for Structures. In joining fresh concrete to concrete that has already set, or to preceding layers, thoroughly clean the surface of work already in place of all laitance, loose, and foreign material. Then, wash and scrub this surface with wire brooms and thoroughly drench with water until saturated. Keep the surface saturated until placing new concrete. Immediately before placing new concrete, draw all forms tight against concrete already in place. After interrupting concrete placement and forming a construction joint, interlock with the succeeding concrete by forming suitable keys in the concrete. Form these keys by inserting and subsequently removing beveled wood strips. Thoroughly saturate the wood strips with water before inserting them. The Department may allow the use of steel dowels instead of keys. The Engineer will determine the size and placement of keys and dowels.
C.Non-Structural Concrete Items. When non-structural concrete items are constructed on top of rigid pavement, ensure that construction joints in the non-structural items coincide with the pavement joints. Install expansion joint material 1/2 inch thick and cut it to conform to the cross section of the non-structural item at all construction joints. When a construction joint is within 100 feet of a break in alignment or a drainage structure; treat the construction joint as a contraction joint.
601.03.11 Falsework. Design and construct falsework that provides the necessary
rigidity, supports the loads imposed, and produces, in the finished structure, the lines and 601-22 grades specified in the Plans. Have a Regist ered Professional Engineer design all falsework that is not a Department standard design for structures with clear span lengths of 20 feet or more and all falsework where traffic openings are specified. Furnish the Engineer detailed working drawings in triplicate and design calculations for falsework. Do not begin any falsework construction until the Engineer has reviewed the falsework drawings. Take full responsibilit y for any falsework constructed prior to the Engineer's review of falsework drawings. Do not place any concrete until the Engineer has completed the review of the falsework drawings. Provide time for the Engineer to complete this review that is proportionate to the complexity of the falsework design; however always provide at least 3 weeks. For falsework over railroads or navigable streams, the Engineer’s review of the falsework drawings will be contingent upon the drawings being satisfactory to the railroad company involved, US Coast Guard, Army Corps of Engineers, or other agency having jurisdiction, as applicable. The Department will allow the revision of falsework drawings at any time. When requesting a revision, allow sufficient time for the Engineer’s review before starting construction on the revised portion. When using footing type falsework foundations, decide the bearing value of the soil, and show the values assumed in the design of the falsework on the falsework drawings. Show assumed values for both wet and dry soil conditions. Construct slab forms between girders with no allowance for settlement relative to the girders. Ensure that the design load for falsework consists of the sum of dead and live vertical loads. Include the weight of concrete, reinforcing steel, forms, and falsework in the dead loads. Assume the weight of concrete, reinforcing steel, and forms to be no less than 160 pounds per cubic foot of concrete. In addition to the full dead load, assume a live load of 50 pounds per square foot for horizontal surfaces and finishing machine weight, if necessary, in the design of falsework and centering. Design the falsework so that horizontal loads are resisted in any direction by diagonal bracing, blocking, ties, or other means the E ngineer approves, to be no less than 2 percent of the total dead load. Design falsework footings to carry the load imposed upon them without exceeding the estimated soil bearing values and all anticipated settlements. When post-tensioning the concrete, design the falsework to support any increased or readjusted loads caused by the post-tensioning. Ensure that the design of all plywood form panels and studs supporting them is as specified for forms. Design all joists s upporting slabs and overhangs as falsework. When falsework is over or adjacent to roadways or railways, install all details of the falsework system which contribute to horizontal stability and resistance to impact at the time each element of the falsework is erected and leave them in place until removing the falsework. Construct falsework to reasonably conform to falsework drawings. Use materials in the falsework construction of the quality necessary to sustain stresses required by the falsework design. Use workmanship in falsework construction of such quality that the falsework will support the loads imposed without excessive settlement or deformation. Use suitable jacks or oak wedges in connection with falsework to set the forms to the required grade and to take up any excessive settlement in the falsework, either before or while placing concrete. If unanticipated events occur, including undue settlements, which in the opinion of the Engineer would prevent obtaining a structure conforming to the Contract, discontinue placing concrete and provide corrective measures satisfactory to the Engineer. In the event satisfactory measures are not provided before ini tial set of the concrete in the affected area, discontinue placing concrete at a location the Engineer determines. Remove all unacceptable concrete. Do not place temporary supports or shoring u nder prestressed concrete or structural steel girders when paving bridge slabs or when taking top of beam elevations. When placing falsework installations over or adjacent to an open public road, include design considerations and protection to ensure that the falsework system is not disturbed by 601-23 errant highway vehicles or from vibration forces caused by passing vehicles. Include provisions to protect traffic from falling objects.
601.03.12 Forming.
A.Forms for Structures. Clean the inside surfaces of forms of all dirt, mortar, and foreign material. Thoroughly coat forms which will later be removed with form oil before use. Do not deposit concrete in forms until completing all work connected with constructing the forms, placing all materials required to be embedded in the concrete for the unit to be poured, and the Engineer has inspected forms and materials. Control the rate of depositing concrete in forms to prevent over stressing the forms due to fluid pressure. Provide forms for all concrete surfaces not completely enclosed or hidden below the permanent ground surface that conform to the requirements herein for forms for exposed surfaces. The Engineer will consider interior surfaces of underground drainage structures the same as to be completely enclosed surfaces. Prior to using the forming system for exposed surfaces and when the Engineer requests, furnish the Engineer the form design and materials data so the Engineer may verify compliance with this section. Design and construct forms for exposed concrete surfaces so the formed surfaces of concrete do not deflect excessively in any direction between studs, joists, form stiffeners, form fasteners, or wales. Place plywood with the face grain perpendicular to the studs or joists. If placement of the plywood with the grain parallel to the studs or joists is desired, furnish the Engineer calculations showing that excessive deflection or stresses will not occur. Provide a clear span between supporting studs or joists that is no more than 20 times the thickness of the form facing and that does not deflect more than 1/360 of the clear span. Should any form or forming system, even though previously reviewed before use, produce a surface with excessive bulges, discontinue its use until making modifications satisfactory to the Engineer. Form all exposed surfaces of each element in a concrete structure with the same forming material or with materi als which produce similar surface textures, color, and appearance. Face forms for exposed surfaces with form panels. Only use form panels in good condition free of defects, such as scar s, dents, or delaminations, for exposed surfaces. In general, furnish and place form panels for exposed surfaces in uniform widths of 3 feet or more and in uniform lengths of 5 feet or more, except where the dimensions of the member formed are less than these dimensions. Arrange panels in symmetrical patterns conforming to the general lines of the structure. Precisely align form panels on each side of the panel joint using supports or fasteners common to both panels, to obtain a continuous, unbroken concrete plane surface. Construct forms for exposed surfaces with 3/4 inch chamfer strips attached to prevent mortar runs and to produce smooth, straight chamfers at all sharp edges of the concrete. Grinding of chamfers is not allowed as a primary construction method. Grinding is only acceptable as a mean s of correction or repair as approved by the engineer. Use form fasteners consisting of form bolts, clamps, or other devices as necessary to prevent spreading of the forms during concrete placement. Do not use twisted wire loop ties to hold forms in position. The Department will allow casting of anchor devices into the concrete for later use in supporting forms or for lifting precast members when the Engineer allows. Do not use driven types of anchorages for fastening forms or form supports to concrete on bridge decks. 601-24 Construct all forms to allow removal without damaging the concrete. Frame forms for copings, offsets, railings, and all ornamental work so there will be no damage to or marring of the concrete when removing the forms. Leave openings in forms at intervals no greater than 10 feet vertically. Ensure that the openings are adequate to allow free access to the forms for the purpose of inspection, working, and vibrating the concrete. Set and maintain all forms true to lines and grades designated until the concrete has hardened. After placing concrete, remove the forms according to Subsection 601.03.14. For narrow walls where access to the bottom of forms is not readily attainable otherwise, leave the lower form boards loose so they may be removed to remove all chips, dirt, sawdust, or other extraneous material from inside the forms immediately before placing concrete. Construct metal ties or anchorages within the forms to allow their removal to a depth of at least one inch from the face without injury to the concrete. Design all fittings or metal ties such that upon their removal the cavities that remain will be the smallest possible size. Regardless of their position in the completed construction, ram and fill cavities with mortar, and ensure that the surface is sound, smooth, even, and uniform in color. When using ordinary tie wires within the forms for areas where concrete will be exposed and will receive surface finish, cut back all wires at least 1/4 inch from the face of the concrete with chisels or nippers. Fill the resulting cavities with mortar, and ensure that the surface is sound, smooth, even, and uniform in color. Use nippers for cutting wires in fresh concrete. Cut the wires that are not included within the areas where the concrete will receive surface finish flush with the concrete surface. The Engineer will not require grouting unless concrete is damaged in cutting wires. Maintain forms that are intended for reuse in good condition to ensure accuracy of shape, strength, rigidity, mortar tightness, and surface smoothness. Do not use forms that are unsatisfactory in any respect in the opinion of the Engineer and remove them immediately from the job site. Use forms for circular section concrete columns that are plastic, plastic lined, metal, or other approved material in order to provide a smooth and true surface free from fins, joints, and other irregularities. Apply the above wooden form specifications relative to design, mortar tightness, filleted corners, beveled projecti ons, bracing, alignment, removal, reuse, and oiling to metal forms, also. Countersink all bolt heads. Design clamps, pins, or other connecting devices to hold the forms rigidly together and to allow removal without injury to the concrete. Keep metal forms free from rust, grease, or other foreign matter that may discolor the concrete.
B.Forms for Non-Structural Construction. Provide forms used for non-structural construction, free from warps, of sufficient strength to resist warping during construction, and of a height approximately equal to the depth of the section to be constructed. Thoroughly clean, oil well, and securely stake, brace, and hold forms to the required line and grade before depositing any concrete. Use approved flexible forms for construction of circular sections where the radius is 100 feet or less.
C.Slip Forming for Non-Structural Construction. The Department will allow the use of slip form or extruding machines for non-structural concrete items whose design is compatible with the slip form or extrusion process. For concrete placed by the slip form or extrusion process, the Engineer may waive the minimum slump requirements for the concrete being placed. Control the slump so that during each continuous run the maximum range of slump between the various batches or loads does not exceed one inch. Produce items by the slip form or extr usion process that are comparable in quality to those produced by use of side form methods. When work is not satisfactory, the Engineer may require the use of side forms instead of the slip form 601-25 or extrusion process, as well as corrective work.
D.Slip Forming for Bridge Barrier Wall. The Department will allow slip form construction of bridge barrier wall when the Engineer approves test sections. Test sections will be the first 25 feet in length and may be poured on the structure with the Engineer’s prior approval. If test sec tions are unacceptable, the Contractor will remove the entire test section at no expense to the Department. Core or slice the test section as the Engineer directs. The Engineer will review the cores or slices to ensure concrete consolidation around the horizontal steel reinforcement. When concrete is not consolidated around the steel or the quality is not comparable to the side form methods, the Engineer may require the use of side forms and corrective work. The Engineer may waive the minimum slump requirements. Control the slump so that during each continuous run, the maximum range of slump between the various batches of loads does not exceed one inch. Conform to the alignment tolerance requirements of Subsection 601.03.18. Construct joints and bevels according to the Plans. Construct barrier wall to the dimensions specified on the Plans.
601.03.13 Camber. Set falsework and forms to provide structural camber indicated
or as directed.
601.03.14 Removal of Falsework and Forms. In determination of time for removal
of falsework and forms, consider the location and character of the structure, weather, and other conditions influencing hardening of the concrete and materials used in the mixture. Do not remove falsework centering and falsework supporting any concrete work or loosen any wedges without obtaining the Enginee r’s permission. Even with the Engineer’s permission, take full responsibility for the safety of the work. The Department will allow the removal of forms for ornamental work, railing, parapets, and vertical surfaces that do not carry loads after 18 hours, unless otherwise directed or approved. Column forms may be removed after 18 hours, provided no significant structural loads will be placed before concrete design strength is reached.
1.The Department will allow the removal of supporting forms and falsework for structural units subjected to bending stresses, 3 days after placing the last concrete in the unit upon conformance to the following conditions:
a.Advise the Engineer in writing at least 24 hours in advance of placing concrete that early removal is necessary or desirable, and request that additional cylinders for the required testing be made.
b.Submit, for approval, a written request for the intended use of any special procedures or modifications to the mixture such as increased cement content, use of Type III cement, use of high range water reducing admixture. If supplying a high range water reducing admixture, subject to the Engineer’s approval, the Department will allow the use of a higher than specified slump.
c.Ensure that results of the compressive strength tests demonstrate a minimum of 80% the required 28-day compressive strength for the class of concrete specified. The Engineer will sample for compressive strength at the minimum frequencies indicated in the Manual of Field Sampling and Testing Practices. The Department will cast and test compressive strength cylinders according to KM 64-305 and ASTM C 39, respectively. Cure cylinders to be tested for early removal of forms and falsework as nearly as possible in the identical manner that the concrete in the structural unit is cured. The Engineer will allow early removal of forms and falsework when all of the cylinders achieve the specified minimum compressive strength. Upon conforming to the above conditions, the Department will allow the removal of supporting forms and falsework for structural units subjected to bending stresses to begin 3 days after placing the last concrete in the unit. 601-26
2.If early release cylinders are not requested or have failed strength requirements, do not remove the falsework, centering, and forms supporting any girder, slab, beam, arch, or member subject to direct bending stress, or forms inside concrete barrels, until the minimum curing time has elapsed as shown in the following table. The Engineer will take air temperature readings at approximately 7:30 AM and 3:00 PM each day during the curing period and determine the average temperature from those readings. The curing time will start after placing the last concrete in the member considered. The Engineer will add one day to the following calendar days shown in the table for each day the average ambient air temperature falls below 40 F. REQUIRED TIME IN CALENDAR DAYS BEFORE REMOVING FORMS AND FALSEWORK (1) Item Average Ambient Temperature During Curing Period 41 to 54 °F 55 to 69 °F 70 °F or more Box Culverts, spans 10 feet or less 18 11 7 Box Culverts, spans 10 to 20 feet inclusive 18 12 8 Slab and Girder Spans, 10 feet or less, including Slab Spans between Steel Girders 18 11 7 Slab and Girder Spans, 10 to 20 feet inclusive, including Slab Spans between Steel Girders 18 12 8 Slab and Girder Spans, over 20 feet, including Slab Spans between Steel Girders 21 15 12 Caps of Concrete Pile Bents, Open Column Abutments, and Piers 18 11 7 Caps of Piers with Copings extending 3 feet or less beyond Web Walls 7 5 3 Curbs or Slabs Overhanging 2 feet or less, and Rails in Open Handrails 7 5 3 Falsework under Web Walls 7 5 3 Curbs or Slabs Overhanging more than 2 feet 18 11 7 Walls, Columns, and Vertical Sides of Beams and Girders 18 hours min. as the Engineer directs (1)For mixtures using Type IP cement or fly ash, see Subsection 601.03.03
3.Remove falsework and centering in such a manner and sequence that allows concrete to uniformly and gradually take the stresses due to its own weight. Remove forms without defacing the structure. Always remove forms from the sides of columns and piers before removing falsework or centering beneath 601-27 girders, beams, or other members that they will support, so the Engineer may inspect the quality of concrete. The Engineer will not grant any extension of time to complete work due to falsework remaining in place during curing.
4.Box culvert top slab forms may be removed earlier than 3 days. Submit special mix design and early release cylinder plan to the Engineer for approval if removal of forms earlier than 3 days is desired.
601.03.15 Opening to Traffic. Conform to the following requirements for the time
of opening a completed structure to traffic or a pplication of significant loads. The Engineer will consider construction equipment pass ing over a structure to be traffic.
1.The Engineer will allow early opening to traffic or application of significant loads under the same criteria as early removal for forms and falsework with the following additional requirements:
a.Ensure that results of the compressive strength tests demonstrate a minimum of 100% the required 28 days compressive strength, for the class of concrete specified.
b.When possible, continue to cure concrete for the time specified in the following table even when the specified strength requirements have been met.
2.If early release cylinders are not requested or have failed strength requirements, do not open the structure to traffic or subject it to significant loads until the minimum time has elapsed as specified in the Required Time in Calendar Days Before Removing Forms and Falsework table in Subsection 601.03.14 and the Required Time in Calendar Days Before Applying Significant Loads on Concrete Structures table in this subsection. The curing time will start after placing the last concrete in the structure, with the exception of handrails not designed as load supporting members. The Engineer will add one day to the following calendar days shown in the table for each day the average ambient air temperature falls below 40 F. The Engineer will take air temperature readings at approximately 7:30 AM and 3:00 PM each day during the curing period and determine the average temperature from those readings. 601-28 REQUIRED TIME IN CALENDAR DAYS BEFORE APPLYING SIGNIFICANT LOADS ON CONCRETE STRUCTURES Item Average Ambient Temperature During Curing Period 40 to 54 °F 55 to 69 °F 70 °F or more Box Culverts, spans 10 feet or less 21 13 10 Box Culverts, 10 to 20 feet inclusive 22 14 11 Slab and Girder Spans, 10 feet or less, including Slab Spans between Steel Girders 21 13 10 Slab and Girder Spans, 10 to 20 feet inclusive, including Slab Spans Steel Girders 22 14 11 Slab and Girder Spans, over 20 feet, including Slab Spans between Steel Girders 23 18 14 Overhanging Slabs, age before barrier walls are placed(2)(3) 23 18 14 Caps on Concrete Pile Bents, Open Column Abutments, and Piers Concentrated Loads, as produced by steel superstructures or precast concrete 18 11 7 Distributed Loads, as produced by poured-in- place concrete deck girder superstructures 3 2 1(2) Class “D” Piles, Moved or Driven(1) 28 21 21 Class “D” (HES) Piles, Moved or Driven(1) 7 5 3 Class “D” Modified Piles, Moved or Driven(1) 14 10 7 Bridge Barrier Wall(4) 23 18 14 Backfill against Abutments or Retaining Walls 14 10 7 Pole and Sign Base Foundations Setting the poles or truss legs Tensioning of Messenger Cables or installation of overhead trusswork. 14 28 10 21
1.See Subsection 604.03.
2.No strength requirements apply.
3.The Engineer will not apply time limits when falsework is designed to support barrier wall.
4.Opening to traffic is considered applying a significant load
601.03.16 Joints.
A.Expansion and Contraction Joints for Structures. Construct expansion joints to allow absolute freedom of movement. After completing all work, use a fine 601-29 chisel to carefully remove all loose or thin shells or mortar likely to spall under movement from expansion joints. Provide and place expansion joints at locations specified in the Plans and Standard Drawings as follows:
1.Friction or Sliding Joints. Friction or sliding joints may be either metal, neoprene, rubber, or premolded filler type as specified.
2.Open Joints. Place at locations designated and form by insertion and subsequent removal of a template of timber, metal, or other suitable and approved material. Use a method of insertion and removal of joint templates that avoids the possibility of chipping or breaking the edges and construct the templates so removal is readily accomplished without injury to the work. Do not extend reinforcement across an open joint unless specified in the Plans. Carefully set structural steel angles, channels, plates, or other shapes used in connection with open joints to conform to the crown and grade of the bridge deck. Construct the joint with a uniform opening and to dimensions specified in the Plans.
3.Special Types. Use special types other than those listed when specified in the Plans or when the Engineer so orders in writing. Furnish special details for such joints.
B.Expansion Joints for Non-Structural Items. Install expansion joints at all breaks in alignment and at all locations where one concrete construction abuts another concrete or other type construction. Install expansion joints at each 1,000 feet of continuous construction. The Engineer will not require steel reinforcement in expansion joints. When another concrete item crosses an expansion joint in JPC pavements, construct the expansion joint for the structural or non-structural concrete item one inch wide and construct all other expansion joints 1/2 inch wide. The Engineer will not require expansion joints in paved ditches except at locations where the paved ditch abuts another structure. Cut the one-inch thick expansion joint material to conform to the cross section of the concrete.
C.Contraction Joints for Non- Structural Concrete Items. Either form 1/8-inch wide contraction joints for non-structural concrete items or construct them according to requirements of this subsection at intervals not to exceed 30 feet, except when items are constructed on or adjacent to a rigid pavement or shoulder. For these exceptions, make the joint spacing coincide with that of the pavement or shoulder. Space contraction joints for si dewalks as specified in Section 505. The Engineer will not require the sealing of contraction joints in non-structural items. The Engineer will not require contraction joints for paved ditches. Construct sawed contraction joints to a minimum depth of 2 inches, except that the Engineer will allow one inch of depth for header curbs and integral curbs.
601.03.17 Curing Concrete. Cure reinforced concrete bridge slabs according to
Subsection 609.03. Wet cure all surfaces that are to receive a masonry coating finish, unless using combination material. When using combination material, cure as specified in B) below. Either wet cure all other concrete, exce pt pipe culvert headwalls, as specified in A) below or cure it by application of membrane forming compound as specified in B) below. The Engineer will not require curing for cast-in-place pipe culvert headwalls. At any time the Engineer determines concrete on the project is not being properly cured, the Engineer may suspend all or any concreting operations on the project. At any time during the curing period when the atmospheric temperature is 45 F or less, protect the concrete to satisfy the temperature requirements according to Subsection
601.03.09 D).
A.Wet Curing. Cure concrete for a period of at least 7 calendar days, beginning immediately after placement and finishing, by frequently applying water to all 601-30 surfaces to keep them continuously damp during the full 7-calendar day curing period or until the required strength is attained. Protect exposed concrete surfaces from drying by application of a double thickness of wet burlap or similar approved material and keep the burlap or other approved material continuously wet for a period of 7 or more calendar days. Soak new burlap in water for at least 12 hours before the first use. When the structure or any portion thereof is enclosed and artificial heat is provided for protection, the Engineer will not waive the moist curing requirement. When using steamlines for heating, leave the pipe loose so sufficient steam escapes into the housing to maintain a moist atmosphere at all times. When using stoves or salamanders, maintain vessels containing water on each stove or salamander to maintain a moist atmosphere at all times. The Department will allow the curing of flat horizontal surfaces with curing blankets.
B.Membrane Curing. Do not dilute or alter the membrane forming curing compound. Thoroughly agitate the compound immediately before using it. When the compound is too viscous to apply, warm it in a water bath to approximately 100 F before applying. Uniformly apply the compound to a surface by use of an approved pressure sprayer. The Department will allow the placement of curing compound in one application. When placing in one application, achieve uniform and satisfactory coverage. If the Engineer directs that 2 applications are required because one application is not satisfactory, then make each application at the rate of one gallon per 300 or less square feet. Start the first application as soon as practical after the final finish and as the Engineer directs, and start the second application after finishing the first application. Use a total actual application rate of at least one gallon per 150 square feet or less actual coverage. Do not apply curing compound to construction joints, reinforcing steel, or surfaces to receive a masonry coating, except:
1.The Department will allow the use of materials conforming to the water retention requirements of AASHTO M 148 for liquid membrane forming curing compound, and also conforming to Section 828 for masonry coating, on areas designated to receive masonry coating. Combination materials will be so designated on the List of Approved Materials for Masonry Coating Materials
2.When using combination materials, follow wet curing procedures until completing all patching or other surface corrections and applying the compound. Keep the surface covered with wet burlap or other approved material and alternately expose small sections for surface corrections, to avoid drying. Conform to surface pr eparation requirements for masonry coating in all respects. When inadvertently applying curing compound or masonry coating to surfaces upon which the compound is not allowed for use, remove it by sandblasting or high-pressure water cleaning with or without abrasives added to water stream. Some compounds may require chemical removal. When chemical cleaners are used, neutralize compounds and fully rinse surface with clean water. Do not damage finished concrete. Correct any damage at no cost to the Department. Allow surface to dry before proceeding. Protect the curing compound and maintain it in an acceptable condition for a period of at least 7 calendar days. Moisten and respray curing compound on surfaces on which the curing compound is damaged before the end of the 7-calendar day curing period. Cover surfaces upon which curing compound has been applied and that will be used as work surfaces or otherwise subject to damage to the curing compound with planks, boards, or other protective material to protect the curing compound from damage.
C.Curing Blankets. Only use curing blankets for curing bridge deck slabs and other 601-31 flat horizontal surfaces. Keep the concrete continuously damp for the period of time specified for the item being constructed, beginning immediately after placing and finishing. As soon as possible, without damaging the concrete surface, moisten the concrete by applying water, and immediately cover the surface with the curing blankets. Place the blankets so that adjoining blankets overlap at least 18 inches. Weight all laps and outside edges to prevent displacement of the blankets before completing curing. Ensure intimate contact between the blankets and the concrete surface. If the blankets are disturbed before the curing time expires, immediately replace them. Apply water at any time drying of the concrete is evident. Immediately repair torn places in the blankets by cementing an additional thickness of the same material over the torn area. At the end of each curing period, inspect the blankets; repair all tears or holes before reusing the blankets.
601.03.18 Surface Finish. Apply the following surface finishes to various parts of
concrete structures:
1.Ordinary Surface Finish,
2.Masonry Coating Finish, or
3.Floated Surface Finish. Apply ordinary surface finish to all concrete surfaces not required to have masonry coating finish or a floated surface finish. Consider ordinary surface finish as a final finish on all surfaces not required to have masonry coating. Ensure that exposed finished concrete surfaces do not vary more than 1/4 inch in 10 feet as measured from a straightedge.
A.Ordinary Surface Finish. Immediately following removal of forms, remove all fins and irregular projections from all surfaces except those not to be exposed in the completed work. On all surfaces, that have cavities and depressions resulting from removal of form ties, and all other holes, honeycomb spots, broken corners or edges, and other defects, thoroughly clean the defects, saturate them with water, and carefully point them. Use a mortar of the same cement and fine aggregates mixed in the same proportions as used in the class of concrete being finished. Do not use a mortar that is more than 30 minutes old, and cure the mortar patches as specified for the structures. After the mortar has thoroughly hardened, finish it to obtain a uniform and smooth surface that is the same color and texture as in the surrounding concrete. When required, chip out honeycomb areas before pointing. Carefully tool all open and filled contraction and expansion joints in the completed work and keep them free of all mortar and concrete. Expose the joint filler for its full length with clean true edges. Obtain smooth and even surfaces of uniform color and texture without unsightly bulges, patched areas, depressions, and other imperfections. The Engineer will consider individual surfaces satisfactory and in compliance with requirements for ordinary surface finish when the surfaces have been formed and finished as specified and the Engineer has approved the resultant surface as to uniformity, color, texture, and smoothness. The Engineer will consider each face of a column, wing, girder, or parapet separately in determining if the finish is satisfactory. Protect all exposed surfaces from subsequent construction operations and from drip and disfigurement. Clean and finish any surface disfigured as a result of construction or other operations as the Engineer may require to give a satisfactory surface finish.
B.Masonry Coating Finish. After the Engineer has inspected and accepted the concrete surfaces of bridges and median barriers as having a satisfactory ordinary surface finish, clean the concrete surfaces specified hereinafter of all dust, foreign 601-32 matter, and form oil, and apply a Department approved masonry coating finish. Coat the following surfaces, including all beveled edges:
1.Bridge End Bents, Abutments, Retaining Walls, and Headwalls for box or long span underpasses - every exposed surface including wingwalls, above a point 6 inches below ground or fill line.
2.Bridge Pier Caps - the tops (including exposed surfaces of pads, pedestals, and keys), sides and ends. Do not apply the coating to bearing areas.
3.Bridge Superstructure - the tops, inside and outside faces, and ends of all barrier walls, parapets, curbs, and plinths that will be exposed. Do not apply the coating to the riding surface of the bridge deck.
4.Median Barriers - all exposed surfaces of concrete median barriers and concrete terminal sections appurtenant to the barriers.
5.Exposed Surfaces of Substructure and the Superstructure of Highway, Railway, and Pedestrian Bridges Over a Highway - all surfaces identified in 1), 2), and 3) above and the underneath surfaces of slab overhangs that are outside of exterior girders and the exterior side and bottom of exterior beams, girders and box beams and all exposed surfaces of piers, abutments and walls that are within 200 feet of a public road or street. Extend the masonry coating from a point 6 inches below ground line to the top of the exposed surface. Thoroughly clean all surfaces to rece ive a masonry coating and keep them free of oil, form oil, grease, dust, di rt, mud, curing compound, release agents, loose patching mortar, or any other substance that may prevent bonding. Before applying the masonry coating material, fill all air holes flush with the surface with the masonry coating material or an approved mortar to provide a uniform surface. Surfaces that will receive Masonry Coating Finish must have a roughened surface that meets manufacturer’s recommendations for product performance. Check all surfaces to receive a masonry coating for the presence of dust by wiping a dark cloth across the surface of the concrete. If a white powder can be seen on the dark cloth, clean the concrete by wire brushing, grinding, or water blasting and then allow it to thoroughly dry before applying the masonry coating. The Engineer will recheck the surface for the presence of dust after cleaning. Check all surfaces to receive a masonry coating for the presence of oily conditions by sprinkling or fogging water on the surface of the concrete. If the water stands in droplets without spreading out immediately, this indicates the surface is contaminated with an oily substance, and the Engineer will require cleaning using a detergent and water followed by thorough rinsing with water. The Engineer will recheck the surface for the presence of oily conditions after cleaning. Thoroughly dry all surfaces to receive a masonry coating before applying the coating, unless the coating manufacturer sp ecifically recommends the surface to be wet. The Department’s List of Approved Materials contains each manufacturer’s recommendation. The Engin eer will not consider surfaces to be dry unless an absorbent paper pressed tightly against the surface does not show any trace of moisture. Suspend coating application any time the ambient temperature or the temperature of the concrete does not comply with the coating manufacturer’s recommendations. Prior to application of the materials, furnish the Engineer with copies of the coating material manufacturer’s brochures or booklets. Apply masonry coating materials in strict conformity with the manufacturer’s written instructions and apply the material at a uniform rate of at least 50 10 square feet per gallon. Satisfactorily repair or remove any portions of the coating that are not clean, uniform in color, texture, thickness, tightly bonded, or that are damaged before final acceptance of the project and replace them with an acceptable finish and 601-33 coating. Provide a neat uniform appearance, and prevent the coating from being dripped, sprayed, or otherwise deposited upon concrete or steel surfaces not designated to receive the coating. Remo ve any objectionable deposits or material and repair the surfaces to th e Engineer’s satisfaction.
C.Floated Surface Finish. Finish horizontal surfaces not subject to wear, and those that do not receive the Masonry Coating Finish, such as back walls, and headwalls, by placing an excess of materials in the form and removing or striking off such excess with a wooden template, forcing coarse aggregate below the mortar surface. Do not use mortar topping for surfaces falling under this classification. After striking-off the concrete as described, thoroughly work the surface and float it by hand with a wooden float leaving a fine grained, smooth-sanded surface. Finish concrete bridge floors as specified in Section 609. Finish sidewalks on structures as specified in Section 505.
601.03.19 Construction Date and Identification. On all concrete bridges and box
culverts, stencil the year the Contract was ex ecuted and the structure drawing number on the concrete at the locations designated. Make the figures on the stencil according to details specified in the Plans. For bridges having a clear span of 20 feet or more, stencil the year the Contract was executed and load capacity of the structure on the outside face of the plinth or barrier wall as shown on the Standard Drawing or as directed. On all box culverts, place stenciled figures giving the year in which the Contract is executed on the inlet end of the culvert on the outside face and center of the parapet or headwall. Do not use permanent plates or markers of any kind, other than thos e shown, on any structure. On all bridges, imprint the name(s) of the prime contractor, and the subcontractor when applicable, in the concrete at the location shown or designated. Furnish stencils, all equipment, tools, labor, materials, and other incidentals necessary.
601.04 Measurement.
601.04.01 Concrete. The Department will measure the quantity in cubic yards
according to the dimensions specified in the Plans. The Department will not measure the volume of concrete displaced by pile heads (except when using concrete piles) for payment and will consider it incidental to this item of work. The Department will measure the volume of concrete displaced by concrete pile heads in cubic yards. The Department will not measure forming, including permanent steel forms, for payment and will consider it incidental to this item of work.
601.04.02 Steel Reinforcement. The Department will measure the quantity according
to Subsection 602.04.
601.04.03 Masonry Coating. The Department will measure the quantity in square
yards.
601.04.04 Mass Concrete. The Department will measure the quantity in cubic yards
actually placed.
601.05 PAYMENT. The Department will make payment for the completed and accepted
quantities under the following: Code Pay Item Pay Unit 08100, 08102-08106, 02555 Concrete, Class Cubic Yard 08150 Steel Reinforcement See Subsection 602.05 02998 Masonry Coating Square Yard 10040 Mass Concrete
1.Cubic Yard 601-34
1.The Department will pay for Mass Concrete at a unit price of 2 times the delivered cost of the concrete. When mixing concrete on site, the Department will pay for Mass Concrete at one-half the contract unit price for that class concrete. The Department will consider payment as full compensation for all work required under this section. Appendix A Construction Tolerances Concrete for structures and pavements; accur acy of individual ingredient materials for each batch. ± 2% for aggregates. ± 1% for water. ± 1% for cement in batches of 4 cubic yards or greater. ± 1% for total cementitious materials in batches of 4 cubic yards or greater. 0% to + 4% for cement in batches less than 4 cubic yards. 0% to + 4% for total cementitious materials in batches less than 4 cubic yards. ± 3% if total admixture dosage required ≥ 34oz. ± 1 oz. if total admixture dosage ˂ 34oz. 601-35 SECTION 602 - STEEL REINFORCEMENT
602.01 DESCRIPTION. Furnish and place steel for reinforcement of concrete. Furnish
bars, spirals, welded wire fabric, bar mat, or other specified reinforcement, of the quality, type, size, and quantity designated by the Contract.
602.02 Materials.
602.02.01 Steel Reinforcement. Conform to Section 811.
602.02.02 Epoxy Coating Material. Conform to Section 811.
602.02.03 Welded Steel Wire Reinforcement (WWR). Conform to Section 811.
602.03 Construction.
602.03.01 Protection of Material. Handle and store steel reinforcement to prevent
bending, excessive rusting, or contamination with objectionable substances.
602.03.02 Straightening. Before placing in the work, straighten reinforcement bent
during shipment or handling without injuring the steel. Do not heat the steel, or use steel with sharp kinks.
602.03.03 Bending. Bend reinforcement cold to the dimensions and shapes specified
in the Plans and to within tolerances designat ed in the CRSI Manual of Standard Practice. In bending, do not injure the steel. Bend bars in the shop before shipment, not in the field.
602.03.04 Placing and Fastening. Accurately place all steel reinforcement as shown,
and firmly hold in position while placing and during hardening of concrete. Hold in position to within a tolerance of 1/2 inch, and place to within a tolerance of 1/4 inch of specified clearance from the face of concrete, except for bridge deck reinforcement steel. Place steel reinforcement for bridge slabs to within the tolerances specified in Subsection 609.03.03. Dimensions shown from the face of concrete to bars are clear distances. Bar spacings are from center to center of bars. Tie bars at all intersections, except where spacing is less than one foot in both directions, then tie alternate intersections. Always pass vertical stirrups around the main tension members and securely attach them to the members. Use Engineer approved supports to maintain distances from forms and to accurately position reinforcement as necessary. Use precast blocks composed of mortar or Engineer approved supports for holding reinforcement from contact with the forms. Ensure that the tips of metal chair supports in contact with the surface of the concrete are plastic coated steel. When using plastic coated steel supports, provide a minimum of 1/8 inch thickness of the plastic material between the metal tips and the exposed surface of the concrete. The Engineer will accept metal supports as specified for epoxy coated bars. Securely tie down the steel placed in reinforced concrete slabs to prevent any possibility of steel rising above the specified elevation during placing, vibrating, and finishing the concrete as required by Subsection 609.03. Ensure that metal supports have a shape that will be easily enveloped by the concrete. Separate the top and bottom mats of bars with precast mortar blocks, Engineer approved supports or by other equally suitable de vices. Do not use pebbles, pieces of broken stone or brick, metal pipe, and wooden blocks as separators. Securely place reinforcement in any member, and then obtain the Engineer’s approval before placing concrete. The Engineer may reject concrete placed in violation of this provision. When using epoxy or non-epoxy adhesive or gr out to install steel reinforcing bars into existing concrete, provide an approved Type IV epoxy resin system conforming to Section 826 or if included in the proposal, the Special Note for Non-Epoxy Adhesives. Drill and install reinforcing to the embedment depth shown in the plans. Install epoxy or non- epoxy adhesive in accordance with the manufacturer’s recommendations including 602-1
Source: Kentucky Standard Specifications for Road and Bridge Construction, 2019 Edition. Pages 278–312 of 718.