Art. 503.01 Concrete Structures does not contain a pay item for rock excavation for structures and this item is required, it will be paid for according to Article 109.04. Removal and disposal of unstable and/or unsuitable material will be paid for at the contract unit price per cubic yard (cubic meter) for REMOVAL AND DISPOSAL OF UNSUITABLE MATERIAL FOR STRUCTURES. When the contract does not contain a pay item for removal and disposal of unstable and/or unsuitable material for structures and this item is required, it will be paid for according to Article 109.04. Where it is necessary to excavate below the plan bottom of footing elevation, the excavation will be paid for at the contract unit prices for the class of excavation involved. Furnishing and placing the crushed stone, gravel, or other material will be paid for according to Article 109.04. Cofferdams, when specified, will be paid for at the contract unit price per each for COFFERDAM (TYPE 1) or COFFERDAM (TYPE 2), at the locations specified. When added to the contract, cofferdams will be paid for according to Article 109.04. Tree removal and protection of existing plant material will be paid for according to Section 201. Additional suitable material required for backfilling within the roadbed, will be paid for according to Article 109.04. When ordered by the Engineer in writing, cofferdam inspection by a certified diver will be paid for according to Article 109.04. SECTION 503. CONCRETE STRUCTURES
503.01 Description. This work shall consist of constructing cast-in-place
concrete structures.
503.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Portland Cement Concrete ..................................................................... 1020
b.Protective Coat ....................................................................................... 1023
c.Preformed Expansion Joint Fillers .......................................................... 1051
d.Waterproofing Materials ..................................................... 1060.01 - 1060.08
e.Nonmetallic Water Seals ........................................................................ 1054
f.Reinforcement Bars .................................................................................. 508
g.Grout .................................................................................................. 1024.01
h.Metal Hardware Cast into Concrete .................................................... 1006.13
503.03 Equipment. Equipment shall be according to the following.
Item Article/Section
a.Hand Vibrator ................................................................................ 1103.17(a)
b.Vibrating Screed ....................................................................... 1103.17(g)(1)
c.Finishing Machine ........................................................................... 1103.13(a)
d.Fogging Equipment ......................................................................... 1103.17(k)
e.Underwater Concrete Placement Equipment ..................................... 1103.18 Concrete Structures Art. 503.05 CONSTRUCTION REQUIREMENTS
503.04 Excavation and Backfill. Excavation and backfill shall be according
to Section 502. Substructures, foundations, and footings shall be constructed in open excavation wherever practicable.
503.05 Falsework. The falsework shall be designed, constructed, and
maintained for the required loads and site conditions. The Contractor shall submit detailed plans and computations for falsework, prepared and sealed by an Illinois Licensed Structural Engineer, for examination by the Engineer. If such plans are not satisfactory to the Engineer, the Contractor shall make such changes in them as may be required. For continuous concrete slab and cast-in-place concrete girder bridges, falsework shall be provided for the full length of each continuous unit and the full width of the structure. For calculating the strength of falsework, a weight (mass) of 150 lb/cu ft (2400 kg/cu m) shall be assumed for the concrete. The design of the falsework shall take into account the weight of the concrete and also other loads incidental to the construction operations. All falsework shall be designed and constructed to provide the necessary rigidity and to support the imposed loads without appreciable settlement or deformation. The Contractor shall make allowance for the deflection, shrinkage, and settlement of falsework, in addition to the allowance for the amount of dead load deflection and camber shown on the plans. A method satisfactory to the Engineer shall be used to detect any settlement that may occur during the placing of the concrete. Falsework bents shall be founded upon piling driven to a capacity sufficient to support the load without appreciable settlement. If the soil is firm and well compacted, the Contractor may, as an alternate, place falsework bents upon concrete footing or mud sills of sufficient size that the pressure on the soil will not exceed 1 1/2 tons/sq ft (145 kPa) or the Contractor may support falsework from the piers or abutments, provided sleeves for any tie bolts can be cast into the concrete. Sleeves or other appurtenances cast into the concrete shall be constructed so as to permit their removal to a depth of at least 1 1/2 in. (40 mm) from the face without injury to the concrete. Drilling into existing piers or abutments that are to remain as a part of the final structure will not be permitted for the support of falsework. The Engineer may require the Contractor to use screw jacks or hardwood wedges to take up any settlement in the form work, either before or during the placing of the concrete. Falsework supporting forms for cast-in-place concrete shall remain in place until tests show that the concrete has attained the required flexural strength and the curing period is completed. In the absence of tests to determine the flexural strength, the falsework shall remain in place until at least 14 days have elapsed after the placing of the concrete, exclusive of days in which the temperature falls below 45 °F (7 °C). When either fly ash or ground granulated blast-furnace slag has been used in the concrete mixture, falsework shall remain in place a minimum of 28 days from the time of concrete placement in the absence of strength tests. Art. 503.06 Concrete Structures No superimposed load, either dead or live, will be allowed upon the bridge or component during the period the falsework is required to remain in place. If longitudinal construction joints are provided in the roadway of any superstructure, the falsework shall not be released under one portion adjacent to such a joint until the concrete in that portion has attained the required strength and the concrete has been placed in the portion on the opposite side of such joint. The falsework shall not be removed from either side of such joint until all the concrete has attained the required flexural strength and the curing period is completed. A compressive strength established through field testing to be equivalent to the required flexural strength may be used if approved by the Engineer. Falsework shall be removed in such a manner as to permit the concrete to take uniformly and gradually the stress due to its weight (mass).
503.06 Forms. Forms shall be set and maintained to the lines and grades
shown on the plans, and shall be tight to prevent concrete leakage. For continuous concrete slab and cast-in-place concrete girder bridges, forms shall be provided for the full length and width of each continuous unit formed. The Contractor shall submit detailed plans for forms for review and approval by the Engineer. A weight (mass) of 150 lb/cu ft (2400 kg/cu m) shall be assumed for the concrete in the design of the forms. The design of the forms shall provide for accommodation of incidental loads, settlement, deadload deflection, shrinkage, and deformation of the form components. The forms shall provide the structural capacity required to produce finished concrete to the lines and grades specified on the plans. Forms shall be constructed of wood or metal. Supporting or attaching forms by welding to or drilling or cutting holes in beams will not be allowed. Wood forms for exposed surfaces shall be made of dressed lumber or plywood. Except for curved and special surfaces, wood forms shall be surfaced on both sides and both edges and shall be sized to uniform thickness. Metal forms shall be of such thickness that they will remain true to shape. All bolts and rivet heads in contact with concrete shall be countersunk. Clamps, pins, and other connecting devices shall be designed to hold the forms rigidly in place and to allow removal without injury to the concrete. Metal forms which do not present a smooth surface or line up properly shall not be used. Metal forms shall be free from rust, grease, or other foreign matter. Forms shall be filleted at all sharp corners. Triangular moldings used for fillets or V-shaped notches shall have two equal sides. Where the size of the molding is specified, the dimension stated shall be the width of each of the equal sides. Moldings for fillets and notches shall be 3/4 in. (19 mm). The moldings for corners on handrails and handrail posts shall be 1/2 in. (13 mm). All moldings shall be cut with true edges, surfaced on all sides, and not warped, cracked, or frayed. Forms shall be given a bevel or draft in case of all projections, such as girders and copings. Concrete Structures Art. 503.06 When directed by the Engineer, temporary openings shall be provided in the bottom of forms for cleaning out all extraneous material immediately prior to placing concrete. Tie rods, bolts and anchorages within the forms shall be constructed so as to permit their removal to a depth of at least 1 1/2 in. (40 mm) from the face without injury to the concrete. Wire ties, when used, shall be cut back at least 1/2 in. (13 mm) from the face of the concrete upon removal of the forms, except on surfaces not exposed to view, they may be cut flush. All fittings for metal ties shall be of such design that, upon their removal, the cavities which are left will be of the smallest practicable size. Prior to reinforcement bar placement, forms shall be coated with form oil. When the surfaces are not exposed to view, wood forms may be saturated with water, in lieu of form oil, immediately prior to placement of the concrete. Forms shall remain in place until permission is obtained from the Engineer for their removal. For Class SI concrete substructure components that will be self- supporting after the forms are removed, and for Class BS concrete components, except those defined in Article 503.16(b), the forms shall remain in place until the concrete has attained the required flexural strength and the curing period is completed. For the remainder of cast-in-place concrete components the forms shall remain in place at least 24 hours. Superimposed loads, either dead or live, shall not be applied to a concrete component during the period the forms are required to remain in place, and until the component has attained sufficient strength to support subsequent loads. In the absence of tests to determine the flexural strength, the forms shall remain in place until at least 14 days have elapsed after placing the concrete, exclusive of days the temperature falls below 45 °F (7 °C). When either fly ash or ground granulated blast-furnace slag has been used in the concrete mixture, forms shall remain in place a minimum of 28 days from the time of concrete placement in the absence of strength tests. A compressive strength established through field testing to be equivalent to the required flexural strength may be used if approved by the Engineer. The method of form removal shall not result in damage to the concrete. If forms are removed prior to the completion of the required curing period, curing shall be resumed with an approved curing method for the remainder of the curing period. Additional requirements for form liners and bridge deck forms shall be as follows.
a.Form Liners. When form liners are specified, the Contractor shall submit plans for the form liner pattern along with an installation procedure for approval by the Engineer. All form liner joints and tie holes shall be sealed. Form release agents shall be according to the recommendations of the form liner manufacturer. The form release agent shall be compatible with all curing agents and admixtures. Art. 503.06 Concrete Structures The temperature differential between the form liner and concrete shall not be greater than 9 °F (5 °C) for normal ambient conditions. During cold weather, the form liner shall be applied in the same ambient conditions as concrete placement is to take place. In ambient conditions above 90 °F (32 °C), form liner attachment shall allow for thermal expansion. Variations in dimensions for the cast-in-place concrete with a textured surface shall be within the following tolerances: the width and depth of textured joints shall be within ± 1/8 in. (± 3 mm); the location of the joints shall be within ± 1/2 in. (± 13 mm); and the maximum variation of a joint from a straight line shall be ± 1/4 in. (± 6 mm) in 10 ft (3 m). A 2 x 2 ft (600 x 600 mm) test sample that includes the proposed textured surface shall be cast and supplied to the Engineer for his/her approval 30 days prior to pouring the cast-in-place concrete.
b.Bridge Deck Forms. Forms used in casting concrete bridge decks will not be allowed to remain in place permanently. All tie rods, bolts, anchorages, brackets, and other forming hardware which is incorporated into the bridge deck shall be either epoxy coated or galvanized. Areas of epoxy coating which have been damaged shall be repaired. When the Contractor uses cantilever forming brackets on the exterior beams or girders, the following procedures will be required.
1.Bracket Placement. The resulting force of the leg brace of the cantilever bracket shall bear on the web within 6 in. (150 mm) of the bottom flange of the beam or girder.
2.Beam Ties. The exterior beams or girders, supporting cantilever forming brackets, shall be tied together. On stage construction where cantilever brackets are supported on one exterior line of beams or girders, this line shall be tied to the furthest opposite interior line. The ties shall be spaced at 4 to 8 ft (1.2 to 2.4 m) centers; except, when steel beams or girders are used and the finishing machine rails are located outside of the exterior beam or girder, the tie spacing shall be 4 ft (1.2 m) maximum. Cross frames on steel girders which do not have a top strut shall not be considered a tie. Ties shall be a minimum of No. 4 (No. 13) epoxy coated reinforcement bars with threaded ends. Each tie bar shall be furnished with a tie bar stabilizing system capable of drawing the tie bar taut. The tie bar stabilizing system shall be approved by the Engineer and shall consist of adjustable tie clips, lag studs, and turnbuckles. The tie clips shall mechanically attach to the outside fascia girder or interior girders as required, and the individual tie bar. The tie bars shall be placed parallel to the transverse reinforcement. The tie bar shall not be placed lower than the bottom transverse reinforcement or higher than the top transverse reinforcement. No welding will be permitted to the structural steel or stud shear connectors, or reinforcement bars for concrete Concrete Structures Art. 503.07 beams, for the installation of the tie bar stabilizing system. After installation, the tie bar shall be drawn taut until the bar does not vary from a straight line from center of tie clip to center of opposite tie clip.
3.Beam Blocks. Hardwood 4 x 4 in. (100 x 100 mm) blocks, or material of an equivalent strength, shall be wedged between the webs of exterior and first interior beams within 6 in. (150 mm) of the bottom flanges at each location where the top of the beams are tied together. If the Contractor elects to use cantilever brackets with an alternate procedure, the Contractor shall submit design calculations and detailed plans for approval by the Engineer.
503.07 Placing and Consolidating. No concrete shall be placed on ice,
snow, or frozen foundation material. The method and manner of placing concrete shall be such as to avoid segregation or separation of the aggregates or the displacement of the reinforcement. The external surface of all concrete shall be thoroughly worked during the operations of placing in such a manner as to work the mortar against the forms to produce a smooth finish free of honeycomb and with a minimum of water and air pockets. Open troughs and chutes shall extend as nearly as practicable to the point of deposit. Dropping the concrete a distance of more than 5 ft (1.5 m) or depositing a large quantity at any point and running or working it along the forms will not be permitted. The concrete for walls with an average thickness of 12 in. (300 mm) or less shall be placed with tubes so that the drop is not greater than 5 ft (1.5 m). For self-consolidating concrete, the maximum distance of horizontal flow from the point of deposit shall be 15 ft (4.6 m). The distance may be increased if the dynamic segregation index (DSI) at the maximum flow distance is 10.0 percent or less according to ITP SCC-8 (Option C). The maximum distance using the DSI shall be 25 ft (7.6 m). In addition, this specified horizontal flow distance shall apply to precast products. In the case of precast prestressed concrete products, refer to the Department’s “Manual of Fabrication for Precast Prestressed Concrete Products” for the specified horizontal flow distance requirements. When the form height for placing the self-consolidating concrete is greater than 10 ft (3.0 m), direct monitoring of form pressure shall be performed by the Contractor according to ITP SCC-10. The monitoring requirement is a minimum, and the Contractor shall remain responsible for adequate design of the falsework and forms. The Contractor shall record the formwork pressure during concrete placement. This information shall be used by the Contractor to prevent the placement rate from exceeding the maximum formwork pressure allowed, to monitor the thixotropic change in the concrete during the pour, and to make appropriate adjustments to the mix design. This information shall be provided to the Engineer during the pour. When concrete is pumped, the equipment shall be suitable in kind and adequate in capacity for the work and arranged so that vibrations will not damage freshly placed concrete. Aluminum pipe or conduit will not be permitted in pumping or placing concrete. Mixed concrete shall be supplied to maintain continuous operation of the pumping equipment. Art. 503.07 Concrete Structures When air entrained concrete is pumped, an accessory or accessories shall be incorporated in the discharge components to minimize air loss. The maximum allowable air loss caused by the pumping operation shall be 3.0 percent with the minimum air content at the point of discharge meeting the requirements of
Article 1020 — 04.
Placing of concrete shall be regulated so that the pressures caused by the concrete shall not exceed those used in the design of the forms. Special care shall be taken to fill each part of the forms by depositing the concrete as near its final position as possible, to work the coarser aggregates back from the face, and to force the concrete under and around the reinforcement bars without displacing them. Leakage through forms onto beams or girders shall not be allowed to harden and shall be removed while in a plastic state. The concrete shall be consolidated by internal vibration unless self-consolidating concrete is used. Self-consolidating concrete may be used for inaccessible locations where consolidation by internal vibration is not practicable. The self-consolidating concrete shall be rodded with a piece of lumber, conduit, or vibrator if the material has lost its fluidity prior to placement of additional concrete. The vibrator will only be permitted if it can be used in a manner that does not cause segregation as determined by the Engineer. Any other method for restoring the fluidity of the concrete shall be approved by the Engineer. The Contractor shall provide and use a sufficient number of vibrators to ensure that consolidation can be started immediately after the concrete has been deposited in the forms. The vibrators shall be inserted into the concrete immediately after it is deposited and shall be moved throughout the mass so as to thoroughly work the concrete around the reinforcement, embedded fixtures, and into the corners and angles of the forms. Vibrators shall not be attached to the forms, reinforcement bars, or the surface of the concrete. Application of vibrators shall be at points uniformly spaced and not farther apart than 1 1/2 times the radius over which the vibration is visibly effective. The vibrator shall penetrate through each successive layer and into the preceding layer sufficiently to uniformly blend the two layers together. The duration of the vibration at the points of insertion shall be sufficient to thoroughly consolidate the concrete into place but shall not be continued so as to cause segregation. When consolidating concrete in bridge decks and approach slabs, the vibrator shall be vertically inserted into the concrete for 3 - 5 seconds or for a period of time determined by the Engineer. Vibration shall be supplemented by spading when required by the Engineer. Concrete shall be placed in continuous horizontal layers and up to a maximum depth of 20 in. (0.5 m). When it is necessary by reason of an emergency to place less than a complete horizontal layer in one operation, such layer shall terminate in a vertical bulkhead. Separate batches shall follow each other closely and in no case shall the interval of time between the placing of successive batches be greater than 20 minutes. Concrete Structures Art. 503.09 If mix foaming or detrimental material is observed during placement or at the completion of a pour, the material shall be removed while the concrete is still plastic. After the concrete has taken its initial set, care shall be exercised to avoid jarring the forms or placing any strain on the ends of projecting reinforcement.
503.08 Depositing Concrete Underwater. Concrete shall not be exposed to
the action of water before setting, or deposited in water, except with the approval of the Engineer and under his/her immediate supervision. When concrete is deposited underwater, it shall be carefully placed in its final position by means of a tremie or concrete pump and shall not be disturbed after being deposited. Still water shall be maintained at the point of deposit and all form work designed to retain concrete underwater shall be watertight. The consistency of the concrete shall be carefully regulated and segregation of the materials shall be prevented. When the tremie or concrete pump line is pre-lubricated with a cement/water mixture, the excess material shall be wasted. The discharge end of the tremie or concrete pump line shall be sealed prior to starting concrete placement according to Article 1103.18. The steel pipe shall be lowered to the bottom of the excavation and filled with concrete. The steel pipe shall be lifted slightly to allow the concrete to flow out of the steel pipe and embed the discharge end in concrete. The discharge end of the steel pipe shall remain embedded in the concrete throughout concrete placement. If, at any time the discharge end is not embedded in the concrete during placement, work shall be stopped and the steel pipe brought to the surface. The steel pipe shall be resealed according to Article 1103.18 and the process restarted. All vertical movements of the steel pipe shall be done in a manner to prevent a loss of concrete embedment. Concrete placement shall be continuous. If concrete placement is interrupted for longer than 30 minutes and resistance to flow is anticipated, the steel pipe shall be brought to the surface, the discharge end resealed according to Article 1103.18, and the process restarted. Horizontal distribution shall be accomplished by halting placement, raising the steel pipe to the surface, then horizontally moving the steel pipe to its new location, reestablishing the seal according to Article 1103.18, and the process restarted. Horizontal distribution may also be accomplished by simultaneously using multiple tremie pipes. The maximum distance between tremie insertions or tremie spacings shall be limited to three times the depth of the pour. The concrete shall not be vibrated when placed underwater, and the method of depositing the concrete shall produce approximately horizontal layers.
503.09 Construction Joints. Construction joints shall be made only at
locations shown on the plans or approved by the Engineer, except in cases of breakdowns or other unforeseen and unavoidable delays. All construction joints shall be bonded unless noted otherwise. When not shown on the plans, their location shall be confined, as far as possible, to regions of low Art. 503.09 Concrete Structures shearing stress and to locations that will be hidden from view. When possible, the location of construction joints shall be planned in advance and the concrete placed continuously from joint to joint. The reinforcing steel shall extend through such joints. If a construction joint is necessary in the sloped portion of a wingwall or similar location where a featheredge would result, the joint shall be constructed so as to produce an edge thickness of not less than 6 in. (150 mm) in the succeeding layer. No construction joint shall be placed within 18 in. (450 mm) of the top of any wall or pier unless the details of the work provide for a coping having a thickness of less than 18 in. (450 mm), in which case, at the option of the Engineer, a construction joint may be made at the underside of the coping. The face edges of all joints which are exposed to view shall be carefully finished true to line and elevation. Shear keys, formed into or out from the surface of the previously placed concrete or steel dowels, shall be used where required. Shear keys formed into the concrete shall be formed by the insertion and subsequent removal of beveled wood strips which shall be thoroughly saturated with water prior to insertion. Steel dowels may, at the discretion of the Engineer, be used in lieu of keys. The size and spacing of the keys and dowels will be as determined by the Engineer. Between adjacent sections of retaining walls and abutment walls, a V-shaped groove shall be formed in the exposed face of the walls by the use of 1/2 in. (13 mm) triangular molding on each side of the joint. Care shall be exercised not to injure the concrete or break the concrete-steel bond at any time. In constructing bridge decks and approach slabs where longitudinal joints are specified, a platform shall be constructed outside the longitudinal joints and supported on the lower form, and personnel will not be permitted to stand or walk on the projecting reinforcement bars until the concrete has hardened. The Contractor, subject to approval of the Engineer, may pour a bridge deck full width with horizontal bonded construction joints between the deck and curbs, parapets, or sidewalks.
a.Unbonded Construction Joints. Unbonded construction joints shall be made by forming or striking off the initial concrete placed to a true and even surface and allowing it to set. Loose material shall be removed. The new concrete shall be thoroughly consolidated against the existing concrete.
b.Bonded Construction Joints. For bonding to hardened concrete, the existing cement paste shall be removed to create a prepared surface. The surface shall be prepared by washing with water under pressure or by sandblasting to expose clean, well bonded aggregate. To facilitate the removal of the cement paste, the form in contact with the first pour or the exposed surface of the first pour, may be thoroughly covered with a surface retarder. When the surface retarder is applied directly to the fresh concrete surface, its application shall be completed within 30 minutes after concrete placement. The surface retarder shall be a ready-to-use liquid compound that delays the set of a concrete surface, and shall be approved by the Engineer in advance Concrete Structures Art. 503.12 of beginning the work. It shall produce results satisfactory to the Engineer and will be evaluated on the tests performed by the Engineer, and on the manufacturer's data recommendations. The prepared surface of the existing concrete shall be wetted a minimum of one hour before application of the new concrete. The surface shall be maintained in a dampened condition during that period. Immediately before placing the new concrete, any excess water shall be removed.
503.10 Expansion Joints. Expansion joints shall be constructed to permit
freedom of movement. After all other work is completed, all thin shells of mortar and projections of the concrete into and around the joint space that are likely to spall under movement or prevent the proper operation of the joint shall be carefully removed. Expansion joint devices shall be furnished and installed according to Section 520.
a.Open Joints. Reinforcement shall not extend across or into an open joint. Open joints in railings or under projecting portions of rail posts shall be formed with square corners unless beveled corners are specified. When not protected by metal expansion guards, open joints in decks and sidewalks shall be finished with an edging tool satisfactory to the Engineer.
b.Filled Joints. When preformed joint filler is specified, the material may be any one of the types specified in Section 1051. The preformed joint filler shall be placed in correct position before the adjacent concrete on one side of the joint is poured. The joint filler shall be cut from the least practicable number of pieces to fit exactly and completely fill the space shown on the plans. Loose fitting or open points between sections of filler or between filler and forms will not be permitted.
c.Edge Supports. The plates, angles, or other structural shapes provided as edge supports at open joints between adjacent spans shall be furnished and installed according to Article 520.03.
503.11 Drainage Openings. When specified, drain holes shall be
constructed in abutment walls, wingwalls, retaining walls, and culvert sidewalls. The locations of drains on all concrete superstructures shall be adjusted so as to prevent the discharge of drainage water against any portion of the structure, or directly onto any railroad, highway or unprotected embankment beneath the structure. Drains consisting only of openings formed in the deck and curbs shall be provided with a surrounding drip notch in the bottom surface of the slab. Deck drains shall be placed and securely fastened in position before the concrete is placed.
503.12 Nonmetallic Water Seals. Nonmetallic water seals shall be installed
as shown on the plans. Provisions shall be made to adequately support the water seal during construction. The projecting edges and ends of partially embedded water seals shall be protected from damage. Art. 503.13 Concrete Structures When splices are required, they shall be made by heating or vulcanizing to form continuous watertight joints. For the polyvinylchloride water seal, the heat shall be sufficient to melt but not char the plastic.
503.13 Foundations and Footings. When concrete footings are constructed
in excavation other than rock, forms shall be used for all vertical surfaces, except when the excavation can be made and will remain true to the required lines and grades until the concrete is placed in the excavated space. When forms are omitted, the entire excavated space shall be filled with concrete to the elevation of the top of the footing. When concrete footings are constructed in rock, if the forms are omitted, the entire space shall be filled with concrete up to the top of the footing, or to the top of the rock if the latter is lower. In all cases, where sumps are required for the disposal of water, they shall be constructed outside the footing areas and forms shall be used for the footings at each sump. The concrete footing for each substructure unit shall be placed monolithically, except when joints are specified. Vertical construction and expansion joints shown on the plans in abutments and wing walls shall not extend through the footing. In retaining walls or other structures, where joints extend through the footing, the water seal required in the joints between adjacent sections of wall need not extend below the top of the footing. When concrete encasement is specified, this work shall include the furnishing and placing of the reinforcement required for encasement and any excavation necessary to construct it.
503.14 Seal Coats in Cofferdams. When conditions are encountered which
render it impractical to dewater a cofferdam before placing concrete, the Contractor will be permitted to construct a concrete seal coat. Seal coats will not be authorized, except where properly constructed cofferdams cannot be dewatered satisfactorily by ordinary means. The seal coat shall be constructed below the elevation of the footing and will not be considered a part of the footing. Seal coats shall be designed to withstand the hydrostatic pressure taking into account the resistance afforded by the cofferdam and foundation piles or drilled shafts. Seal coats shall be constructed of Class SC concrete. When seal coat concrete is required underwater it shall be placed according to
Article 503 — 08.
503.15 Surface Finish. Depressions resulting from the removal of ties, and
holes left by attachments to rod or bolt anchorages, shall be neatly pointed with a grout mixed in the proportions of, and color matched to, the concrete being treated. Air pockets or rough places larger than 1/2 in. (13 mm) diameter shall be pointed as specified in the foregoing paragraph. Honeycombed areas shall be chipped out by the Contractor and inspected by the Engineer before being pointed. Concrete Structures Art. 503.15 After being pointed, form liners and all other surfaces that will be exposed to view after completion of the work, except those surfaces specified in Articles 503.16(a) and (b)(1), shall be given a normal finish.
a.Normal Finish. A normal finish shall consist of the removal of fins, rough spots, stains, hardened mortar or grout, and form lines by rubbing with a No. 16 carborundum stone or an abrasive of equal quality without materially changing the texture of the surface. The rubbing shall be continued sufficiently to produce a surface matching the surrounding surface. When the surface of concrete shows a film of oil left from an excess of oil on the forms, or the concrete is oil-stained, or is otherwise not of uniform color, the Engineer may require the Contractor to employ the following cleaning method. Mix one part cement and 1 1/2 parts fine sand with sufficient water to produce a grout having the consistency of thick paint. Cement from the source of the cement used in the concrete shall be used in the grout. Wet the surface of the concrete sufficiently to prevent absorption of water from the grout and apply the grout uniformly with brushes, completely filling air bubbles and holes. Immediately after applying the grout, float the surface with a suitable float, scouring the wall vigorously. While the grout is still plastic, the surface shall be finished with a sponge rubber float removing all excess grout. This finishing shall be done at the time when grout will not be pulled from holes or depressions. Next, allow the surface to dry thoroughly, then rub it vigorously with dry burlap to completely remove any dried grout. There shall be no visible film of grout remaining after this rubbing. The entire cleaning operation for any area must be completed the day it is started. No grout shall be left on the wall overnight. No cleaning operations shall be undertaken until all patching and filling of tie holes has been done.
b.Rubbed Finish. Surfaces to receive a rubbed finish will be designated on the plans. The surfaces shall be thoroughly wet with a brush and rubbed with a No. 16 carborundum stone, or an abrasive of equal quality, bringing the surface to a paste. The rubbing shall be continued sufficiently to remove all roughness and projections, producing a smooth dense surface free from pits and irregularities. The material which has been ground to a paste in the above process shall be carefully spread or brushed uniformly over the rubbed surface and permitted to reset. The final finish shall be obtained by a thorough rubbing with a No. 30 carborundum stone, or an abrasive of equal quality, first wetting with a brush as for the initial rubbing. The finish rubbing shall continue until the entire surface is of a smooth texture and uniform in color.
c.Bearing Seats. Seats for bridge bearings shall be finished smooth at the proper plane and elevation with a steel trowel within 1/8 in. (3 mm) of the specified elevation before the bearings are placed. Seat areas between bearings shall be sloped to drain away from the bearings. After the water sheen has disappeared, the surface shall be given a final finish by brushing with a whitewash brush. The brush shall be drawn across the seat Art. 503.16 Concrete Structures longitudinally with the bridge deck, with adjacent strokes slightly overlapping, producing a uniform, slightly roughened surface with parallel brush marks.
503.16 Concrete Superstructures. The concrete in bridge decks, approach
slabs, or other monolithic superstructures shall be placed in one continuous operation between expansion or construction joints specified. Sidewalks, curbs, and medians shall be placed monolithically with the superstructure unless a construction joint is specified. When falsework is utilized to support steel or precast concrete beams during erection, the falsework shall be removed prior to pouring the deck. The concrete bridge deck or top riding surface of the superstructure shall be constructed so that the top of the finished surface shall be at the final plan elevation after taking into account any anticipated deflection of the supporting members due to the weight of the deck, median, and parapets. Fogging equipment shall be in operation unless the evaporation rate is less than 0.1 lb/sq ft/hour (0.5kg/sq m/hour) and the Engineer gives permission to stop. The evaporation rate shall be determined according to the following formula. ) ( 10 ) 4 . 0 1 )(( 65 . 2 5 . 2 Englishx VrT T Eac ) ( 10 ) 4 ]( ) 18 ( ) 18 [( 565 . 25 . 2 Metricx VT rT E ac Where: E = Evaporation Rate, lb/sq ft/h (kg/sq m/h) cT = Concrete Temperature, °F (°C) aT = Air Temperature, °F (°C) r = Relative Humidity in percent/100 V = Wind Velocity, mph (km/h) The Contractor shall provide temperature, relative humidity, and wind speed measuring equipment. Fogging equipment shall be adequate to reach or cover the entire pour from behind the finishing machine or vibrating screed to the point of curing covering application, and shall be operated in a manner which shall not accumulate water on the deck until the curing covering has been placed. If there is a delay of more than ten minutes during concrete placement, wet burlap shall be used to protect the concrete until operations resume. Concrete placement operations shall be coordinated to limit the distance between the point of concrete placement and concrete covered with curing material. The distance shall not exceed 35 ft (10.7 m). For pour widths greater than 50 ft (15 m), the distance shall not exceed 25 ft (7.6 m).
a.Riding Surfaces of Superstructures. Superstructure riding surfaces shall be finished and textured as follows.
1.Initial Finishing. After the concrete is placed and consolidated, it shall be struck off and finished with a power driven finishing machine. Concrete Structures Art. 503.16 The finishing machine will not be required for that portion of the surface outside of the outer construction joints shown on the plans when the distance from the construction joint to the parapet flow line is less than 6 ft (2 m). The concrete surface in these areas shall be finished with a hand operated float. At the Contractor’s option, a vibrating screed may be used in lieu of a finishing machine for superstructures with a pour width less than or equal to 24 ft (7.3 m). After the concrete is placed and consolidated, it shall be struck off with a vibrating screed allowing for camber, if required. A slight excess of concrete shall be kept in front of the cutting edge at all times during the striking off operation. After screeding, the entire surface shall be finished with hand-operated longitudinal floats per Article 1103.17(e) with a blade width of 6 in. (150 mm). If the Contractor chooses to use a vibrating screed, straightedge testing while finishing will not be required. Long-handled floats per Article 1103.17(f) may be used to smooth and fill occasional porous or open-textured areas in the concrete surface, but shall not be used to float the entire surface. The Contractor shall take immediate corrective action to eliminate the causes of the porous or open-textured areas as they occur. Water will not be permitted to be applied to the surface unless it can be demonstrated to the Engineer that workability cannot be obtained. If water is permitted by the Engineer, it shall be applied in a fine mist by means of a sprayer, at a distance not to exceed 12 in. (300 mm) from the surface. Application by brushes or any other method that concentrates water will not be permitted. Excess concrete, mortar, or paste produced by the finishing process shall not be discarded into areas that will be covered by sidewalks, medians, curbs, or parapets or otherwise incorporated into the work but shall be removed and disposed of properly.
2.Straightedge Testing and Surface Correction. After the finishing has been completed and while the concrete is still plastic, the surface shall be tested for trueness with a 10 ft (3 m) straightedge, or a hand- operated longitudinal float having blades a minimum of 10 ft (3 m) in length and 6 in. (150 mm) in width. The Contractor shall furnish and use an accurate 10 ft (3 m) straightedge or float which has a handle not less than 3 ft (1 m) longer than 1/2 the pour width. The straightedge or float shall be held in contact with the surface and passed gradually from one side of the superstructure to the other. Advance along the surface shall be in successive stages of not more than 1/2 the length of the straightedge or float. Any depressions found shall be immediately filled with freshly mixed concrete, struck off, consolidated, and refinished. High areas shall be cut down and refinished.
3.Texture. All riding surfaces shall be textured in the plastic state and subsequently saw cut grooved after the concrete has cured. Art. 503.16 Concrete Structures
a.Plastic Texture. The texture shall be formed into the plastic concrete with a burlap or artificial turf carpet drag. The burlap or artificial turf shall be attached to a work bridge riding on rails, or other approved device that will permit control of the time and rate of texturing. The burlap or artificial turf carpet shall have a length equal to the width of the pour or from face-to-face of curbs, as applicable. The burlap or carpet shall be laid on the concrete surface and dragged, parallel to the centerline of the roadway, in the direction that the superstructure is being poured with approximately 2 ft (600 mm) of its width in contact with the concrete surface. The drag shall be operated so as to produce a uniform finish. The burlap shall be double thickness and shall be kept saturated with water while in use. The artificial turf carpet may be weighted, if necessary, for maintaining intimate contact with the concrete surface.
b.Saw Cut Grooving. The grooving operation shall not be started until after the expiration of the required curing or protection period and after correcting excessive variations by grinding or cutting has been completed. The grooves shall be cut into the hardened concrete, perpendicular to the centerline, using a mechanical saw device equipped with diamond blades that will leave grooves 1/8 in. wide and 3/16 in. ± 1/16 in. deep (3 mm wide and 5 mm ± 1.5 mm deep). The Contractor shall have the option of constructing the grooves at either a random spacing of 5/8 to 1 1/4 in. (15 to 30 mm) centers with an average spacing of 7/8 in. (22 mm) or a uniform spacing of 3/4 in. (19 mm) centers. The grooving shall be stopped 1 ft (300 mm) from the faces of curbs or parapets and 2 in. ± 1 in. (50 mm ± 25 mm) from deck drains and expansion joints. If grooving must be performed as part of stage construction, the grooving may be deferred until at least two adjacent lanes have been poured. The removal of slurry shall be continuous throughout the grooving operations. The grooving equipment shall be equipped with vacuum slurry pickup equipment which shall continuously pick up water and sawing dust, and pump the slurry to a collection tank. The slurry shall be disposed of off site according to Article 202.03. Cleanup shall be continuous throughout the grooving operation. All grooved areas shall be flushed with water as soon as possible to remove any slurry material not collected by the vacuum pickup. Flushing shall be continued until all surfaces are clean.
4.Surface Smoothness. All riding surfaces shall be tested for trueness at the expiration of the required curing or protection period. The entire surface shall be tested by means of a 16 ft (5 m) straightedge placed parallel to the grade line and touching the surface. Variations measured from the face of the straightedge to the surface of the superstructure shall not exceed 3/16 in. (5 mm). Variations greater than 3/16 in. Concrete Structures Art. 503.18 (5 mm) shall be removed by grinding or cutting. Bushhammering or any method involving impact shall not be used.
b.Concrete Superstructures other than Decks or Approach Slabs. Concrete parapets and railings, and those concrete curbs, sidewalks, and medians not placed monolithically with the deck or slab shall be placed after the deck or slab concrete has attained the required strength and the curing period is complete.
1.Curbs, Sidewalks, and Medians. Forms for concrete sidewalks, curbs, and medians shall be adjusted to correct elevation, camber, and alignment after the deck or superstructure has been placed. After the concreting has been completed, they shall be struck off and finished with floats and trowels. The edge of curbs, or walks not more than 2 ft (600 mm) in width, shall be either beveled by the use of 3/4 in. (19 mm) triangular molding at the top of the face forms or edged with an edging tool. The edge of walks over 2 ft (600 mm) in width shall be finished with an edging tool. Transverse construction joints shall not be edged and transverse grooves shall not be provided. The top surface of sidewalks shall be finished according to
Article 424 — 06, except the surface shall not be divided by grooves.
2.Parapets and Railings. Forms for concrete parapets and railings shall be held rigidly to line and grade and removed without injury to the concrete. Special care shall be exercised to secure smooth, tight fitting forms. All moldings, panel work, and bevel strips shall be straight and true with neatly mitered joints and all corners in the finished work shall be true, sharp, and clean cut. Alignment of forms and grade of top chamfer strips shall be checked immediately after the placing of concrete in the forms. Rail posts, openings, and panels shall be constructed with vertical lines, regardless of the grade on which the railing is constructed.
503.17 Curing. Concrete shall be cured according to Article 1020.13.
503.18 Waterproofing. The surfaces of concrete structures designated on
the plans shall be waterproofed as follows.
a.Surfaces Below Ground. Surfaces below the ground which are to be waterproofed shall be given either one coat of asphalt primer and two mop coats of petroleum asphalt Type I; or two mop coats of asphalt emulsion.
b.Surfaces Above Ground. Surfaces above the ground line which are to be waterproofed shall be given one coat of asphalt primer and two mop coats of petroleum asphalt Type II. With the approval of the Engineer, spraying will be permitted in lieu of mopping. Art. 503.18 Concrete Structures The surfaces to be waterproofed shall be smooth and free from projections or porous places. The surfaces shall be cleaned of dust, dirt, grease, and loose particles and shall be dry at the time the waterproofing is applied. Petroleum asphalt shall not be applied until at least seven days have elapsed after placing of the concrete. Asphalt emulsion may be applied as soon as the forms are removed. No waterproofing shall be done in wet weather, or if local conditions indicate that rain is imminent, or when the temperature of the air in the shade is below 50 °F (10 °C), without the written permission of the Engineer, except as specified for asphalt emulsion below. When waterproofing with petroleum asphalt, the primer shall be applied to the surface of the concrete in a uniform coating and may be applied without heating. The primer shall be applied at least 24 hours before applying the first mopping of hot asphalt. The two mop coats shall be heated to a temperature which will permit uniform application. Asphalt shall not be heated above 350 °F (175 °C). The amount applied in the two moppings shall be approximately 8 gal/100 sq ft (3 L/sq m) of finished work. If any imperfections appear in the waterproofing, additional coats will be required. When waterproofing with asphalt emulsion, two uniform coats, free from holes or holidays, shall be applied. The second coat shall be applied as soon as the first coat has dried. The minimum total quantity applied in the two coats shall be 3 gal/100 sq ft (1 L/sq m). When the temperature of air in the shade is below 45 °F (7 °C), and the requirements of Article 1020.13(d) have been complied with, asphalt emulsion waterproofing may be applied down to a temperature of 32 °F (0 °C). Regardless of the temperature during application the material shall be kept at a temperature above 50 °F (10 °C). A minimum drying time of 24 hours is required before backfilling, but no backfilling shall commence until the requirements of
Article 502 — 10 are met.
503.19 Protective Coat Application. A protective coat shall be applied to the
entire top surface of bridge decks, approach slabs, hubguards, and the top and inside vertical faces of sidewalk, parapets, end posts, and wings when the concrete is at least 14 days old. This work shall be performed after saw cut grooving, and before the bridge is marked and opened to traffic. Before the protective coat is applied, the concrete surface shall have at least a 48-hour drying period since the last rain and shall be cleaned to remove all oil, grime, and loose particles which would prevent the mixture from penetrating the concrete. Immediately prior to application of the protective coat, the surface shall be blown with oil-free compressed air. After the surface is clean and before applying protective coat, relief joints being sealed according to Section 588 shall be covered with a masking tape to prevent protective coat from contacting the vertical faces of the joint. The protective coat shall consist of two applications of the mixture and each application shall be at a rate of 50 sq yd/gal (11 sq m/L) or less. The protective coat shall be sprayed on the surface using hand methods or with a mechanical spraying machine which will perform the work in a satisfactory manner. The spray nozzle(s) shall be within 18 in. (450 mm) of the concrete or as directed by the Engineer. The interior of the distributor tank shall be thoroughly cleaned prior to placing the protective coat therein. Unless otherwise directed by the Engineer, the Concrete Structures Art. 503.21 temperature of the concrete and air shall be 40 °F (4 °C) or higher at the time of application. The second application of the protective coat shall be made when, in the opinion of the Engineer, the concrete has regained its dry appearance. Traffic shall be prohibited from the area until the concrete has regained its dry appearance. If an application of sand is required by the Engineer for blotter material, it will be paid for according to Article 109.04.
503.20 Opening Structures to Traffic. Concrete structures shall be opened
to traffic according to Articles 503.05, 503.06, and 1020.13.
503.21 Method of Measurement. This work will be measured for payment as
follows.
a.Contract Quantities. The requirements for the use of Contract Quantities shall conform to Article 202.07(a).
b.Measured Quantities. This work will be measured for payment in place and the volume computed in cubic yards (cubic meters). The dimensions used will not exceed those shown on the plans or ordered in writing by the Engineer. Increased quantities from the omission of forms for footings will not be measured for payment. Deductions will be made for the volume of piling, except for steel H pile, encased in the concrete. No deduction will be made for the volume of concrete displaced by steel reinforcement, drain holes, floor drains, and expansion joint material. The reduction in quantity of concrete involved in scoring and chamfers 2 sq in. (1300 sq mm) or less in cross sectional areas will be neglected in all measurements for payment. When shown on the plans or ordered in writing by the Engineer, concrete for seal coats will be measured for payment within the cofferdam sheeting. The vertical dimension used in computing the volume will be the average thickness of the seal between the top of the seal not to exceed the elevation shown on the plans for the bottom of the footing and the bottom of the excavation, but in no case lower than the elevation shown on the plans for the bottom of the seal coat. The horizontal dimensions used will be the average measurement from center to center of the interlocks of the sheet piling in opposite walls of the cofferdam, but in no case will these dimensions be taken as more than 2 ft (600 mm) beyond the neat lines of the footing in any direction, except that provision may be made for a sump at one end of the cofferdam if necessary. Reinforcement bars will be measured for payment according to
Article 508 — 10.
Bridge deck grooving will be measured for payment in place and the area computed in square yards (square meters). No deductions will be made for grooving omissions at deck drains, expansion joints, longitudinal joints, or lane lines. Art. 503.21 Concrete Structures Protective coat will be measured for payment in place and the area computed in square yards (square meters). Form liner textured surfaces will be measured for payment in place and the area computed in square feet (square meters). Joint fillers, water seals, drain holes, floor drains and welded wire reinforcement, except when specified, will not be measured for payment. Rubbed finish will be measured for payment in place and the area computed in square feet (square meters).
503.22 Basis of Payment. This work will be paid for at the contract unit price
per cubic yard (cubic meter) for CONCRETE STRUCTURES, CONCRETE SUPERSTRUCTURE, and CONCRETE SUPERSTRUCTURE (APPROACH SLAB). Other cast-in-place concrete for structures will be paid for at the contract unit price per cubic yard (cubic meter) for CONCRETE HANDRAIL, CONCRETE ENCASEMENT, and SEAL COAT CONCRETE. Reinforcement bars will be paid for according to Article 508.11. Expansion bolts, when specified, will be paid for according to Article 540.08. Rubbed finish will be paid for at the contract unit price per square foot (square meter) for RUBBED FINISH. Form liner textured surfaces will be paid for at the contract unit price per square foot (square meter) for FORM LINER TEXTURED SURFACE. Floor drains, other than frames and grates, will be paid for at the contract unit price per each for FLOOR DRAINS. Texturing of bridge decks and approach slabs by saw cut grooving will be paid for at the contract unit price per square yard (square meter) for BRIDGE DECK GROOVING. Protective coat will be paid for at the contract unit price per square yard (square meter) for PROTECTIVE COAT. Concrete protected according to Article 1020.13(d) may be paid for at the adjusted unit prices which will be the following percentages of the contract unit price for the classes of concrete involved. These adjustments will be made only when they are authorized in writing by the Engineer. No adjustment will be made in the contract unit prices for any concrete if winter work is necessary to meet the required completion dates specified in the contract. Precast Concrete Structures Art. 504.02 UNIT PRICE ADJUSTMENTS Percent Type of Construction Adjustment in Unit Price For concrete in substructures, culverts (having a waterway opening of more than 10 sq ft (1 sq m)), pump houses, and retaining walls (except concrete pilings, footings, and seal coats): When protected by: Protection Method II 115 % Protection Method I 110 % For concrete in superstructure (approach slab): When protected by Method I or II 107 % For concrete in superstructures: When protected by: Protection Method II 123 % Protection Method I 115 % For concrete in footings: When protected by Method I or II 107 % For concrete in slope walls: When protected by Method I 107 % SECTION 504. PRECAST CONCRETE STRUCTURES
504.01 Description. This work shall consist of the construction of structures
or portions thereof, with precast concrete or precast, prestressed concrete structural members.
504.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Portland Cement Concrete ..................................................................... 1020
b.Reinforcement Bars ........................................................................... 1006.10
c.Prestressing Steel .............................................................................. 1006.10
d.Welded Wire Reinforcement .............................................................. 1006.10
e.Transverse Tie Rods and Dowel Rods .............................................. 1006.06
f.Nonshrink Grout ................................................................................. 1024.02
g.Epoxy Bonding Compound ................................................................ 1025.01
h.Precast Concrete Products ..................................................................... 1042
i.Preformed Bearing Pads ........................................................................ 1082
j.Metal Hardware Cast into Concrete .................................................... 1006.13
k.Packaged, Dry, Combined Materials for Mortar ...................................... 1017
l.Bond Breaker (Note 1) Note 1. The bond breaker shall be one of the following three options: Two coats of Type I, II, or III membrane curing compound, meeting the requirements of Article 1022.01, applied with a roller.
Referenced in this section
CONCRETE STRUCTURES in other states
Get an email when 503 changes
Illinois revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 327–346 of 1,217. View official source ↗