802CONCRETE FOR STRUCTURES

802.01 Description. This item shall consist of concrete in

bridges, culverts, and miscellaneous structures, in cluding the concrete portion of steel, timber, stone masonry, p recast, prestressed, and composite structures, prepared and constructed according to these specifications and conforming to the lines, grades, dimensions, and designs shown on the plans. Concrete shall consist of approved portland cement, fine aggregate , coarse aggregate, water, and any approved chemical admixtu res mixed in the proportions specified for the various classes o f concrete.

802.02 Materials. The materials used in concrete shall conform

to the requirements specified below. No materials shall be used that contain foreign matter, frost, or lumps or crusts o f hardened substances.

802.03 Handling and Storage of Materials. The handling and

storage of concrete aggregates shall be such as to prevent segregation and contamination with foreign material s. Coarse and fine aggregates shall be separated by bu lkheads or stored in separate stockpiles sufficiently removed from each other to prevent the material at the edges of the piles from becoming intermixed. Coarse aggregate stockpiles not confin ed by bulkheads 665 or bins shall be built up in layers not to exceed 4 ' (1.2 m) in height and each layer shall be completely in place before beginning the next. Coning or building up of stockpiles by depos iting material in one place will not be permitted. In order to contr ol the gradation of the large aggregate for Class B concrete, it may be necessary that the Contractor stockpile the aggregate in two or more g radation ranges, blending by weight as required to obtain the specif ied gradation. There shall be adequate aggregate stockpiled to all ow representative sampling sufficiently in advance of any placement to determine its acceptability, with the minimum amoun t being that required to adequately complete the planned placeme nt. Cement shall be stored in suitable weather-proof bu ildings or silos that will protect the cement from dampness. Provision for storage shall be ample and the shipments of cement as received shall be separately stored in such a manner as to provide easy access for the identification and inspection of each shipment. Stored cement shall meet the test requirements at any time after storage when a re- test is ordered by the Engineer. On small jobs, storage in the open may be permitted by written authorization from the Engineer, in which case a ra ised platform and ample waterproof covering shall be provided.

802.04 Classes of Concrete. The appropriate class of concrete

shall be used in the part of the structure as speci fied or where designated by the Engineer. The classes are as fol lows: Non Air-entrained Air-entrained Miscellaneous Concrete Concrete Concrete Class A Class S(AE) Class M Class B Class S Seal The following requirements shall govern unless othe rwise shown on the plans: Class A concrete shall be used in wingwalls and mis cellaneous construction. Class B concrete shall be used in mass concrete. Class S or S(AE) concrete shall be used in retainin g walls, box culverts, footings, piers, bents, columns, abutment s, and 666 superstructures, including girders, beams, floor sl abs, and parapet walls. Seal concrete shall be used for concrete deposited under water. Class M concrete shall be used in miscellaneous con struction as specified in Sections 500, 600, and 700. Class S(AE) may be substituted for Class S. Class S(AE), Class S or paving concrete under Section 501 may be subst ituted for Class A. Acceptance criteria for strength, water/c ement ratio, and slump shall be that of the Class specified. Differ ent classes of concrete shall not be mixed in the same continuous placement. When Class M concrete is specified, the Contractor may use any commercially produced concrete mix or an approved C lass A, S, S(AE), or paving concrete under Section 501. Unles s otherwise specified, bagged commercial concrete mix may not b e used for Class M concrete. For acceptance purposes, the min imum strength, maximum water/cement ratio, and maximum slump shall be that specified for Class A concrete. For small placemen ts (approximately 1 cubic yard m [ 1 cu m] or less), t he concrete may be mixed on site using a portable mixer. The size of each batch shall not exceed 80% of the manufacturer's rated ca pacity of the mixer. When mixing on site, and with the prior app roval of the Engineer, the materials for each batch may be measu red by volume by converting the mix design weights of each materi al to equivalent volumes.

802.05 Mix Design. (a)General. The concrete mixture shall be

proportioned to ensure a workable and durable concr ete for the various classes, as specified in Table 802-1. The Engineer will not perform any pre-bid testing o f materials. It will be the Contractor’s responsibility to locate a cceptable material sources unless the sources are so noted in the plan s or Special Provisions.

802.06 Quality Control, Acceptance, and Adjustments in

Payments. (a) Quality Control by the Contractor. The Contractor shall be responsible for quality control of materials during handling, blending, mixing, transporting, an d placement operations, and for necessary adjustments in propor tioning of materials used to produce the specified concrete. The Contractor shall be responsible for determining gradation and moisture content of fine and coarse aggregates used in the concrete mixture and for testing the mixture for ai r content, slump, and compressive strength. The Contractor shall det ermine the specific locations for samples and frequency of sam pling for quality control, except the minimum frequency which is list ed below for aggregate gradation shall be used. In addition, th e Contractor shall be required to perform acceptance sampling and test ing at specific 671 times and/or locations specified by the Engineer ac cording to Subsection 802.06(b). Test procedures shall be: Coarse and Fine Aggregates AASHTO T 27 (gradation)* AASHTO T 255 (moisture) Air Content AASHTO T 152 Slump AASHTO T 119 Compressive Strength** AASHTO T 22 (Test specimens for compressive strength determined by cylinders will be obtained according to AASHTO T 23. *1 test per 500 cubic yards (400 cubic meters) of m ix (minimum), sampled from the stockpile. A minimum o f one set of tests per bridge structure will be required. **A minimum of two (2) cylinders shall be cast and tested. Results will be based upon the average result from the two cylinders. An adequate supply of aggregate must be stockpiled to allow representative sampling in advance of any placement , with the minimum amount being that required to complete the day’s planned placement. The initial quality control test result s for gradation must be completed and the test results submitted to the Engineer prior to the beginning of mix production of each class of co ncrete. Subsequent tests shall be taken and tested during p roduction, and the test reports submitted to the Engineer by the end o f the next business day after the sample is taken. Any failing gradati on test result will result in halting production. The aggregate remain ing in the stockpile will be resampled and tested by the Contr actor and the Engineer. If the test results indicate that the ag gregate is outside of the specification limits in Subsection 802.02, the stockpile shall either be corrected or replaced. Passing test repo rts must be submitted to the Engineer before work resumes. The Contractor shall furnish all personnel, equipme nt, and facilities necessary to perform the required sampli ng and testing. The Contractor’s facilities shall be separate from any Field Laboratory and/or Field Office furnished to the Dep artment under the Contract. Quality control sampling and testing by the Contractor shall be performed in a qualified laboratory by a c ertified technician. 672 Requirements for technician certification and labor atory qualification are contained in the Department’s Manual of Field Sampling and Testing Procedures . The Contractor shall maintain records of all samples taken and the results of all tests performed. Test reports shall be signed and copies made availa ble to the Engineer if requested. The Contractor shall certify to the Engineer that t he calibration of the concrete cylinder compression testing machine h as been verified. This verification shall be performed in accordance with AASHTO T 22 and T 67 under any of the following conditions and documented in accordance with AASHTO T 67:

802.07 Measurement of Materials. Materials will be measured

by weighing, except as otherwise specified or where other methods are specifically authorized by the Engineer. Aggre gates shall be measured separately and accurately by weight. Meas uring devices shall be operated in a manner that will consistentl y weigh the cement within ±1% and the individual aggregates wit hin ±2% of the required weight. Measuring devices shall be so des igned and plainly marked that the weights can be accurately and conve niently verified for the quantities of each component actually being used. Cement in standard packages (sack) need not be weig hed, but bulk cement shall be weighed. 677 The mixing water shall be measured by weight or by volume. The water measuring device shall be accurate to wit hin ±1%. Scales shall be satisfactory to the Engineer and sh all be inspected, adjusted, and certified according to Sub section 109.01(f), except that automatic ticket printers and automatic weighing systems will not be required. Where volumetric measurements are authorized by the Engineer for projects where the amount of concrete is small, the weight proportions shall be converted to equivalent volume tric proportions. In such cases, suitable allowance shall be made for variations in the moisture condition of the aggregate, including the bulking effect in the fine aggregate. Representative samples shall be taken and the moist ure content determined for each kind of aggregate. When the ag gregates contain more water than the quantity necessary to produce a saturated surface-dry condition, the batch weights for aggreg ates and water shall be adjusted accordingly.

802.08 Mixing Concrete. Concrete shall be thoroughly mixed in

a mixer of an approved size and type that will ensu re a uniform distribution of the materials throughout the mass. The concrete shall be mixed only in the quantity re quired for immediate use. Concrete that has developed an init ial set shall not be used. Re-tempering concrete will not be permitt ed. Concrete may be proportioned and mixed in a station ary central plant and hauled to the point of delivery in agitat or trucks of approved type or in non-agitating equipment, when a pproved by the Engineer; proportioned in a stationary central plan t and mixed in approved transit mix trucks enroute to the point of delivery; or mixed completely in transit mix trucks at the point of delivery, following the addition of mixing water. The Engineer shall be furnished the manufacturer's rated capacity of each mixer and agitator, along with the recommen ded speed of rotation for the various uses of each mixer. Truck mixers and agitators shall be equipped with means by which the number of revolutions of the drum, blades, or paddles may be readily verified. Mixers and agitators shall not be charged in excess of the manufacturer's rated capacity. Concrete shall be d elivered and discharged from the truck mixer or agitator into th e forms within 1½ hours after the introduction of the mixing water to the cement. In 678 hot weather, or under other conditions contributing to quick setting of the concrete, the maximum allowable time may be reduced by the Engineer. Each batch shall be accompanied by a tim e slip issued at the batch plant. Plants and transit mix trucks shall be equipped wit h adequate water storage and a device for accurately measuring and controlling the amount of water used in each batch. When a sta tionary mixer is used, a mechanical means shall be provided for auto matically preventing the discharge of the mixer until the mat erials have been mixed for a period of not less than one minute. Truck mixers shall be capable of combining the ingr edients of the concrete into a thoroughly mixed and uniform mass, and of discharging the concrete within the specified range of consistency. The concrete shall be mixed not less than 70 nor mo re than 100 revolutions of the drum or blades at the rate of ro tation specified by the manufacturer as the mixing speed. The pick-up and throw-over blades in the drum of all mixers shall be maintaine d in satisfactory condition to assure thoroughly mixed concrete. Agitators shall be capable of maintaining the concr ete in a thoroughly mixed and uniform mass and of dischargin g the concrete within the specified range of consistency. When approved in writing by the Engineer, concrete may be transported in approved non-agitating equipment. B odies of this equipment shall be smooth, watertight, metal contai ners equipped with gates that will permit control of the discharg e of the concrete. Covers shall be provided for protection against the weather. The concrete shall be delivered in a thoroughly mixed a nd uniform mass and discharged within the specified range of consis tency. Placement in forms shall be completed within 30 minutes after introduction of the mixing water to the cement. Concrete shall be mixed according to the mixer manu facturer's specifications in order to obtain an acceptable mas s of concrete. During the period of mixing, the mixer shall operat e at the manufacturer's recommended mixing speed. Additiona l mixing, if any, shall be at the speed designated by the manufa cturer of the equipment as agitating speed. If additional mixing water is required to maintain the specified slump, and is added with the permission of the Engi neer, approximately 20 revolutions of the mixer drum at m ixing speed shall be required before discharge of any concrete. 679 TABLE 802-2 COMPLIANCE, PRICE REDUCTION, & REJECTION LIMITS FOR CONCRETE STRUCTURES Property Compliance Limits Price Reduction Limits Price Reduction Lot Rejection Limits Sublot Rejection Limits Air Content 4% - 8% 3.5%-3.9% and 8.1%-8.4% 3.0%-3.4% and 8.5%-9.0% 10% 20% less than 3.0% and greater than 9.0% less than 2.0% or greater than 10.0% Compressive Strength ≥ f' c 95% f' c or greater 90% f' c or greater but less than 95% f' c 85% f' c or greater but less than 90% f' c 10% 20% 30% Less than 85% f' c Less than 75% f' c f' c is the minimum specified compressive strength in T able 802-1 for the particular class of concrete. 680 When a quality control sample for air content, take n within the allowable time limits for discharge of the concrete and prior to discharge for placement, shows an air content below the specified level by more than the allowable tolerance shown in Table 802-2, the Contractor may use additional air-entraining ad mixture to achieve the desired air content. The air-entrainin g agent and water shall be mixed in a separate container, and the mix ed solution added to the truck mixer and mixed for a minimum of 30 re volutions at the mixing speed. A second air content test shall then be taken to determine if the air content is now within the allo wable limits. The entire contents of the mixer, including wash wa ter, shall be removed from the drum before the addition of materi als for a succeeding batch. There shall be sufficient capacity and transporting equipment to ensure continuous concrete delivery at the rate req uired. If the concrete furnished produces erratic results relative to consistency, strength, or time of initial or final set, the Contractor shall cease the use of that concrete until correcti ons are made to ensure work of the specified quality.

802.09 Handling and Placing Concrete. (a) General. The

Contractor shall provide sufficient supervision, ma npower, equipment, tools, and materials and shall assure pr oper production, delivery, placement, and finishing of the concrete for each placement according to the specifications. Unless otherwise specified, concrete shall be placed continuously be tween authorized construction and/or expansion joints, subject to th e time limits and placement rates specified below. The time interval between batches of concrete shall not exceed 20 minutes. Unless otherwise specified, the minimum p lacement rate shall be 20 cubic yards per hour (15 cu m/h). Any placement that does not produce results that co nform to the specifications shall be repaired or replaced, as re quired, at no cost to the Department. Further placements of a similar na ture and size will not be permitted until corrective measures have bee n taken to assure compliance with the specifications. The minimum placement rate shall not apply to concr ete other than bridges, box culverts, and retaining walls, bu t the interval between batches shall not exceed 20 minutes. 681 In preparation for the placing of concrete, constru ction debris and extraneous matter shall be removed from the interio r of forms. Struts, stays, and braces, serving temporarily to h old the forms in correct shape and alignment pending the placing of concrete, shall be removed when the concrete placement has reached an elevation rendering their service unnecessary.

802.10 Pumping. Concrete may be placed by pumping. The

equipment for pumping shall be arranged and operate d so that no vibrations result that might damage freshly placed concrete. 686 Where concrete is conveyed and placed by mechanical ly applied pressure, the equipment shall be adequate in capaci ty for the work. The operation of the pump shall be such that a cont inuous stream of concrete without air pockets is produced. When pum ping is completed, the concrete remaining in the pipe, if i t is to be used, shall be ejected in such a manner that there will b e no contamination of the concrete or separation of the ingredients. Samples of concrete for slump and air content tests will be obtained at the discharge end of the pipe. The use of aluminum pipe as a conveyance for the co ncrete will not be permitted.

802.11 Depositing Concrete Under Water. Concrete shall not

be deposited in water except when shown on the plan s or with the approval of the Engineer. Concrete deposited in wa ter shall be Seal Concrete. The supply of concrete shall be maintained at the r ate necessary to raise the elevation over the entire seal by a mi nimum of 1' (0.3 m) per hour or an approved retarder shall be used as n ecessary for lesser placement rates. For parts of structures under water, seal concrete shall be placed continuously from start to finish. The surface of the concrete shall be kept as nearly horizontal as practicable. The C ontractor shall provide equipment and personnel to sound the top of the seal in the presence of the Inspector in order to verify the lo cation of the seal at all times. Previously placed seal concrete shall n ot have taken its initial set prior to the placement of adjacent conc rete. Concrete shall be carefully placed by means of a tr emie or other approved method. Still water shall be maintained a t the point of deposit. Concrete shall be deposited in such a man ner that the planned horizontal concrete flow shall be no more t han 15' (4.5 m). This shall be accomplished by locating the points o f deposit in such a manner as to provide for a maximum flow distance of 15' (4.5 m). A tremie shall consist of a tube having a diameter of not less than 10" (250 mm), constructed in sections having flange d couplings fitted with gaskets and an approved foot valve. Th e tremie shall be supported so as to permit rapid lowering when neces sary to retard or stop the flow of concrete. The discharge end shall be closed at the start of the work so as to prevent water entering t he tube and shall be 687 entirely sealed. The tremie tube shall be kept suf ficiently full to prevent the loss of the concrete seal. When a batc h is dumped into the tube, the flow of concrete shall be induced by slightly raising the discharged end, always keeping it in the deposited concrete. If at any time the seal is lost, the tremie shall be rais ed, the discharge end closed for a new start, and then lowered into posit ion with the discharge end in the previously deposited concrete. Aluminum tremies will not be permitted. Dewatering may proceed when the seal concrete has b een allowed to cure for a minimum of 72 hours at a wate r temperature above 45° F (7° C). All laitance or other unsatisf actory materials shall be removed from the exposed surfaces that are to support other structural loads. Prior to the placement, the Contractor shall advise the Engineer of his methods for complying with these requirement s.

802.12 Construction Joints. (a) General. Construction joints

shall be made only where located on plans or shown in the placement schedule, unless otherwise approved by th e Engineer. Before depositing new concrete on or against concre te that has hardened, the forms shall be re-tightened. The placing of concrete shall be carried continuous ly from joint to joint. The face edges of all joints that are ex posed to view shall be carefully finished true to line and elevation. If not detailed on the plans, or in the case of eme rgency, construction joints shall be placed as directed by the Engineer. Shear keys or inclined reinforcement shall be used where necessary to transmit shear or bond the two sections together . When shear keys or inclined reinforcement is not provided, the concrete shall be roughened as directed.

802.13 Falsework. Details for each unit of falsework

construction for bridge span and overhang support s ystems, complete with dimensions and kind and condition of materials, shall be submitted to the Engineer prior to construction for informational 688 and record purposes. These details shall be approv ed by a Registered Professional Engineer, who shall certify that the adequacy of all components has been verified. File copies of all design calculations shall be maintained by the Cont ractor until final acceptance of the project. Construction of the fal sework shall be according to the details submitted to the Engineer for informational purposes. The Contractor shall be responsible for the results obtained by the use of the falsework design. For designing falsework, a weight of 150 pounds per cubic foot (2400 kg/cu m) shall be assumed for fresh concrete. All falsework shall be designed and constructed to provide the ne cessary rigidity and to support the loads without appreciable settle ment or deformation. Falsework shall be set to give the fi nished structure the camber specified. Falsework that cannot be founded on a satisfactory footing shall be supported on piling which shall be spaced, drive n, and removed as specified in the Contractor's falsework details. The use of transverse welds greater than 1 ″ (25 mm) in length used for attachment of hanger brackets, nut plates, or other falsework support devices to the structural steel s hall be approved by the Bridge Engineer prior to construction. The use of welds for attaching screed rail supports larger than 1 ″ (25 mm) diameter to the top flange of the structural steel shall be approve d by the Bridge Engineer prior to construction. All temporary field welds on structural steel shall be performed by a certified welder using low-hydrogen electrodes in accordance with Subsection 807.26 and the ANSI/AASHTO/AWS D1.5 , Bridge Welding Code. Unless otherwise permitted by the En gineer, temporary welds shall be removed by grinding the we ld flush.

802.14 Forms. (a) Standard Forms. Forms shall be mortar-

tight and of sufficient rigidity to prevent distort ion due to the pressure of the concrete and other loads incident t o the construction operations. Forms shall be constructed and maintai ned so as to prevent warping and the opening of joints due to sh rinkage of the lumber. The forms shall be substantial and unyielding and s hall be so designed that the finished concrete will conform to the proper dimensions and contours. The design of the forms s hall take into account the effect of vibration of concrete as it i s placed. 689 Forms for exposed surfaces shall be made of dressed lumber or plywood of uniform thickness, steel, or other appro ved materials that will provide a smooth surface, and shall be mo rtar-tight. Forms shall have 3/4” (20 mm) fillet at all sharp corners unless otherwise directed. In the case of projections, such as gird ers and copings, forms shall be given a bevel or draft to ensure eas y removal. Metal snap-ties within the forms shall be so constr ucted as to permit their removal to a depth of at least 1" (25 mm) from the face of the concrete. Fittings for metal snap-ties shal l be of such design that, upon removal, the cavities that are left will be of the smallest possible size. Metal inserts or anchorages within the forms shall be so constructed as to permit their removal to a depth o f at least 1" (25 mm) from the face of the concrete or be covered by being embedded a minimum of 1" (25 mm) in the concrete. In case ordinary wire ties are permitted, all wires, upon r emoval of the forms, shall be cut back at least 1/4" (6 mm) from the face of the concrete. All cavities shall be filled with cement mortar and the surface left sound, smooth, even, and uniform in color. Forms shall be set and maintained true to the line designated until the concrete is sufficiently hardened. Before depo siting new concrete on or against concrete that has hardened, the forms shall be re-tightened. Forms shall remain in place for the periods specified in Subsection 802.15. When forms appear to be unsa tisfactory in any way, either before or during the placing of con crete, the Engineer shall order the work stopped until the def ects have been corrected. The shape, strength, rigidity, watertightness, and surface smoothness of re-used forms shall be maintained at all times. Any warped or bulged lumber must be re-sized before bei ng re-used. For narrow walls and columns, where the bottom of t he module is inaccessible, the lower portions of the forms shall be so constructed as to facilitate cleaning out of extraneous materia l immediately before placing the concrete. Forms shall be cleaned before being set to line and grade and shall be oiled prior to placing reinforcing steel i n the vicinity of the 690 forms. Materials or methods used in oiling the for ms shall not result in the discoloration of the concrete. In lieu of the conventional stationary forms, concr ete parapet rail may be constructed by using an extrusion machine or other equipment specifically designed for constructing ca st-in-place concrete parapet rail, provided the finished barrie r is true to line and grade and the concrete is properly consolidated.

802.15 Removal of Falsework and Forms. In the determination

of the time for the removal of falsework and forms and the discontinuance of heating, consideration shall be g iven to the location and character of the structure, the weathe r and other conditions influencing the setting of the concrete, and the materials used in the mix. Removal of falsework and forms shall be according t o the following schedule: Minimum Strength Item Time Requirement Bottom Forms for Deck Slabs, Beams, and Caps 7 Days Min. Spec. Top Slabs of RC Box Culverts 7 Days 80% Spec. Forms for Columns and Vertical Walls 24 Hours N/A Side Forms for Footings, Beams, and Caps 12 Hours N/A Side Forms for Parapets, Median Barriers, and Curb Faces 6 Hours N/A 694 Both time and strength requirements must be met bef ore removal of forms and/or falsework begins. Forms on surfaces that will require a Class 2 finis h according to Subsection 802.19 shall be removed at the earliest time permitted under these specifications in order to begin finish ing operations. Forms and their supports shall not be removed witho ut the approval of the Engineer. Supports shall be remove d in such a manner as to permit the concrete to uniformly and g radually take the stresses due to its own weight. Methods of form re moval likely to cause overstressing of or damage to the concrete sh all not be used.

802.16 Weather and Temperature Limitations and Prot ection

of Concrete. When the ambient temperature at the placement sit e is 85° F (29° C) and rising, an approved retarding age nt shall be required in all concrete used in bridge superstruct ures. A retarding agent will not be required in concrete used for bri dge deck curb, parapet, railing, posts, sidewalks, or median treat ment provided they are not placed monolithically with the deck itself. When the internal temperature of the plastic concre te in bridge decks reaches 85° F (29° C), the Contractor shall t ake the necessary precautions to ensure that the temperature of succe eding batches does not exceed 90° F (32° C). Concrete batches wi th temperatures in excess of 90° F (32° C) will be rejected. The m ethod used to control the concrete temperature shall be approved in writing by the Engineer. The temperature of the plastic concrete shall be determined immediately prior to its being deposited in the forms by inserting a thermometer to a depth consistent with the capabilities of the thermometer being used to obtain a true reading . Prior to beginning placement, the Contractor shall ensure th at sufficient materials, labor, and equipment are available durin g placement to implement the previously approved cooling process. The maximum mix temperature for all Class B concret e at the time of placement shall be 75° F (24° C). This req uirement will be strictly adhered to and any concrete delivered to t he job site that does not meet this provision will be rejected. The maximum differential between the internal concrete temperat ure and the concrete surface temperature shall not exceed 36° F (20° C). The Contractor shall devise a method for monitoring the temperature differential for at least seven days and shall have the method approved by the Engineer before the concrete is pla ced. The internal 695 temperature shall be measured as nearly as practica ble to the center of mass of the pour. Methods used to meet these re quirements shall be submitted to the Engineer for approval. Methods that may be used to meet this provision include using ice in th e mixing water, storing cement and aggregates in cool or shaded loc ations, watering down of coarse aggregates, installation of cooling pipes in the concrete, and use of insulation (tenting, quilts, o r sand on polyethylene sheeting). Cooling by watering of fin e aggregates will not be allowed. No concrete shall be placed unless the temperature of the concrete is more than 50° F (10° C) when placed. I f heating of the ingredients is necessary to meet this criterion, it shall be accomplished by a method such as dry heat or steam and not by direct flame. Water shall not be heated to more th an 180° F (82° C), and shall be combined with the aggregate before the addition of cement. Frozen aggregates may not be used. After concrete is placed, it shall be protected by insulated forms, blankets, enclosing and heating, and/or any other m ethod approved by the Engineer that will maintain the temperature adjacent to the concrete at a minimum of 50° F (10° C) for at least 7 days. For concrete other than bridges, box culverts, and reta ining walls, the requirement for maintaining the temperature at or a bove 50° F (10° C) shall not apply, but the concrete shall be protected and/or heated, as necessary, to prevent freezing for a per iod of at least 7 days. For Class B concrete, forms shall remain in place 4 days after placing any time the temperature is below 40° F (4° C) or forecast to drop below 40° F (4° C). In addition, exposed top surfaces of the concrete shall be protected with an insulated blank et. The surface of the concrete shall not be saturated when it is expo sed to freezing air temperatures. The Contractor shall have available and ready for i mmediate use sufficient materials and equipment for maintaining the temperature of the concrete as required above. Concrete that has been frozen or damaged due to wea ther conditions shall be removed and replaced by the Con tractor at no cost to the Department. 696 802.17 Curing Concrete for Structures. (a) Material s. Materials used in curing concrete shall conform to one of the following types:

802.18 Expansion and Fixed Joints. Joints shall be constructed

according to the details shown on the plans.

802.19 Finishing Concrete Surfaces. (a) General. Surface

finishes shall be classified as follows: Class 1. Ordinary Surface Finish. Class 2. Rubbed Finish. Class 3. Textured Coating Finish. Class 4. Exposed Aggregate Finish. Class 5. Tined Bridge Roadway Surface Finish. Class 6. Broomed Finish. Class 7. Grooved Bridge Roadway Surface Finish. All concrete shall be given a Class 1, Ordinary Sur face Finish. In addition, if further finishing is required, such ot her types of finish will be as specified herein. Payment for Class 1 through Class 6 finishes will b e considered a part of the applicable item of concrete used. Meas urement and payment for Class 7 finish will be made according t o Subsections 802.24 and 802.25. Sidewalks shall be given a Class 6 finish. Curbs shall be given a Class 2 or Class 6 finish. Bridge roadway surfaces shall be given a Class 5 fi nish unless Class 7 finish is specified on the plans. The following surfaces shall be given a Class 2 fin ish except when a Class 3 finish is specified on the plans: All Structures. Exposed surfaces of retaining wall s, surfaces of concrete rails, rail posts, rail end posts, rail bases, and parapets, including the outside face. Bridges Over Public Roads. Surfaces above finished ground of piers, columns, abutments, and retaining walls; the outside vertical surfaces of parapets, slabs, and girders; and the underneath side of the overhang outside the exterio r beam. At the option of the Contractor, a Class 3 finish m ay be used on all surfaces requiring a Class 2 finish provided th e same class of finish is used on the entire structure.

802.20 Bridge Roadway Surface Construction. (a) Str iking

Off. After the concrete is placed and consolidated acc ording to Subsection 802.09, bridge roadway surfaces or top s labs of structures serving as finished roadway surfaces sha ll be finished using approved equipment. The Contractor shall sho w the type, size, and weight of the finishing machine and auxil iary equipment that is to be used in the bridge deck construction on the drawings submitted for the span and overhang support system required by Subsection 802.13. Mechanical strike-off machines shall be power drive n, with oscillating type screeds, traveling on rails or hea ders adjusted to conform to the profile or cross section of the road way. The screed shall be adjusted to conform to the profile or the required cross section of the roadway. Consolidation by a vibrato ry action of the finishing machine will not be permitted. The scree ds shall have sufficient strength to retain their shape after adj ustment. The finishing machine shall go over each area of the br idge roadway surface as many times as is required to obtain the required profile and cross section. A slight excess of concrete sha ll be kept in front of the screed at all times. This excess of concret e shall be carried all the way to the edge of the placement or form, and s hall not be worked into the slab but shall be wasted. When a f inishing machine travels on rails supported by fixtures embedded in the concrete area, these supports shall be removed and the holes fille d and finished to the same quality and finish as the surrounding conc rete. The holes shall be cleaned of grease and other foreign matter prior to filling. When non-mechanical strike-off methods are approved , the bridge roadway surfaces or slabs shall be struck of f with a screed 706 that is parallel to the centerline of the roadway, resting on bulk heads or screed strips cut or set to the required c ross section of the roadway. This screed shall be so constructed as to have sufficient strength to retain its shape and the cutting edge s hall be adjusted to conform to the profile of the roadway. Screed stri ps or headers shall be accurately set to the specified grades, checked, and adjusted as necessary prior to the final screeding operation. The screed shall be worked back and forth over the surface until the pr oper profile and cross section is obtained. Longitudinal screeds shall be of sufficient length to finish the full length of spans 50' (15 m) or less in length. Span s over 50' (15 m) in length and continuous spans shall be placed with lengths of placements as shown on the plans. The use of longi tudinal screeds on spans with a horizontal curve is prohibited. Excess water, laitance, or foreign materials brough t to the surface during the course of the finishing operations shall not be reworked into the roadway surface, but shall be removed imme diately upon appearance by means of a squeegee or straightedge d rawn from the center of the roadway surface toward either curb. In general, the addition of water to the surface of the concrete to assist in finishing operations will not be permitte d. If the application of water to the surface is permitted, i t shall be applied as a fog spray by means of approved spray equipment.

802.21 Precast Concrete Products. (a) General. This

subsection pertains to concrete units that have bee n cast prior to erection or installation, and shall include precast concrete slab and girder units, bent caps, rail posts, piling, and ot her items. The casting may be done at the site or at the Contracto r's or Manufacturer's central casting plant and transporte d to the bridge site. The foregoing requirements of Section 802 and those of Section 804 governing materials and construction of reinforced concrete structures, insofar as they are applicable , shall govern the materials requirements, quality control and quality acceptance, and construction methods relative to precast concrete p roducts, except as modified and supplemented by this subsection. In c ase of conflict, the specifications of this subsection shall govern. Concrete in precast products shall be placed in one continuous operation for each unit in a line. The use of spli t pours for multiple units in a prestress line will not be permitted. The Engineer shall be notified prior to beginning a placement and only those completed products bearing identificatio n marks of acceptance by the Department will be permitted for use in 708 construction. The date of casting and a unique ide ntification mark shall be inscribed on each unit.

802.22 Prestressed Concrete Structures. (a) General . This

subsection pertains to all prestressed concrete ele ments in structures and shall govern the manufacture, transportation, a nd storage of 710 beams, slabs, piling, and other structural members of precast concrete prestressed by the pre-tensioning method. This subsection shall govern the installation of all precast prestr essed members except piling, which shall be placed according to t he provisions of Section 805. Plants furnishing precast prestressed concrete prod ucts shall be certified by the Prestressed Concrete Institute. S hop drawings for prestressed concrete structures or components shall be submitted to the Engineer for review and approval before fabrica tion begins. The Engineer shall be notified prior to beginning a placement and only those completed products bearing identificatio n marks of acceptance by the Department will be permitted for use in construction. The date of casting and unique ident ification mark shall be inscribed on each unit.

802.24 Method of Measurement. (a) Concrete of the various

classes will be measured by the cubic yard (cubic m eter) in place, based upon actual volume within the neat lines of t he structure as shown on the plans or revised by authority of the E ngineer. Concrete parapet walls will be included in the volu me of concrete for payment. No deductions will be made for the volume of concre te displaced by reinforcing steel, piling, structural steel, or expansion joint material. No deduction will be made for fillets, s corings, and chamfers 1 square inch (650 sq mm) or less in concr ete cross- sectional area. The quantities shown on the plans will be considere d as the final quantities and no further measurement will be made unless, in the opinion of the Engineer or upon evidence furnished by the Contractor, substantial variations exist between qu antities shown on the plans and actual quantities due to changes in a lignment or dimensions or to apparent errors.

802.25 Basis of Payment. (a) Concrete of the various classes,

completed and accepted and measured as provided abo ve, will be paid for at the contract unit price bid per cubic y ard (cubic meter) for the Class specified, which price shall be full compensation for furnishing all materials, forms, falsework, and bra cing; for mixing, placing, consolidating, finishing, and curing; for performing mix designs and quality control and acceptance sampling and testing; and for all labor, equipment, tools, and incidental s necessary to complete the work. Reinforcing steel, metal drains, and structural ste el placed in this concrete will be paid for under other contract item s. Unless otherwise provided, conduits, joint fillers and sea lers, water stops, flashing, and roofing shown on the plans will not b e measured or paid for separately, but full compensation therefor will be considered included in the contract unit prices bid for the various classes of concrete.

803.01 Description. This item shall consist of cleaning, surface

preparation, and treating concrete surfaces, includ ing concrete cracks, bridge decks, and other concrete surfaces a t the locations shown on the plans. The protective surface treatme nt used will be specified in the Contract and will be one of the th ree classes described in these specifications.

803.02 Materials. The protective surface treatment shall meet

one of the following requirements:

803.04 Method of Measurement. (a) Class 1 Protective

Surface Treatment. Class 1 Protective Surface Treatment applied at the direction of the Engineer will be measured b y the gallon (liter) of boiled linseed oil used in the mixture prior to thinning. The material used for thinning the mixture will not be measured. 724 (b) Class 2 Protective Surface Treatment. Class 2 Protective Surface Treatment will be measured by the square ya rd (square meter). Measurement will be made of the actual are a covered as directed.

803.05 Basis of Payment. (a) Class 1 Protective Surface

Treatment. Work completed and accepted and measured as provided above will be paid for at the contract uni t price bid per gallon (liter) for Class 1 Protective Surface Treat ment, which price shall be full compensation for cleaning, wetting, a nd other preparation of the surface to be treated; for furni shing the linseed oil and thinner; for mixing and application of the mixt ure; and for all labor, tools, equipment, and incidentals necessary to complete the work.

CONCRETE FOR STRUCTURES in other states

• Alaska 501 · CONCRETE FOR STRUCTURES
• Connecticut 6.01 · Concrete for Structures
• Ohio 511 · Concrete for Structures