4−54 SECTION 414 WARM MIX ADDITIVE
414.01 DESCRIPTION . This work consists of incorporating a WMA (Warm Mix Additive) in HMA
(Hot Mix Asphalt).
414.02 MATERIALS. One unit of WMA shall be added to each ton of HMA . All WMA shall be
selected from the RIDOT Approved Materials List and shall be added at a dosage rate recommended by the manufacturer.
414.03 CONSTRUCTION METHODS. If HMA is designated as “with WMA”, the Contractor shall
use a WMA. If HMA is not designated as “with WM A”, the Contractor may request to use a WMA at his own discretion and expense. Additionally, the Engineer may direct the Contractor to use a WMA. If a WMA is used it shall be for an entire day’s production for that class of HMA.
414.04 METHOD OF MEASUREMENT. WMA will be measured by the number of units actually
used in accordance with the specifications and/or as directed by the Engineer.
414.05 BASIS OF PAYMENT The accepted quantity of the WMA will be paid for at its respective
contract unit price per each as listed in the Proposal. 5−1 PART 500 CONCRETE PAVEMENTS SECTION 501 PORTLAND CEMENT CONCRETE PAVEMENT AND BASE
501.01 DESCRIPTION. This work consists of constructing Portland cement concrete base or
pavement, with or without reinforcement, on a prepared subgrade or subbase in reasonably close conformity with the dimensions and details indicated on the Plans, all in accordance with these Specifications. 501.02 MATERIALS. Materials shall meet the requirements of SECTION M.02; PORTLAND CEMENT CONCRETE and SECTION M.05; METALS , of these Specifications.
501.03 CONSTRUCTION METHODS. 501.03.1 Construction Requirements. The classifications, proportioning, testing, batching,
mixing, handling, placing, finishing and curing of Portland cement concrete pavement or base shall conform to the applicable requirements of SECTION 601; PORTLAND CEMENT CONCRETE, of these Specifications. 501.03.2 Equipment.
a.Finishing Machines . Equipment for finishing concrete pavement shall be mechanical, self-propelled, spreading and finishing machines capable of consolidating the concrete and producing a finished surface as specified herein. Finishing machines shall be equipped with at least two oscillating type transverse screeds which shall be adjustable to produce a crowned or flat surface as required.
b.Vibrators. Vibrators, for full width vibration of concrete paving, may be either the surface pan type or the internal types with either immersed tube or multiple spuds. They may be attached to the spreader or the finishing machine, or may be mounted on a separate carriage to accommodate either slip form or side form paving me thods. They shall not come in contact with the joint, load transfer devices, subgrade, reinforcing, or side forms. The frequency of the surface vibrators shall not be less than 3,500 impulses per minute and the frequency of the internal type shall not be less than 5,000 impulses per minute for tube vibrators and not less than 7,000 impulses per minute for spud vibrators. Vibrators shall be rubber tipped to prevent damage to epoxy-coated reinforcing steel.
c.Concrete Saw. When sawing joints is elected or specified, the Contractor shall provide sawing equipment adequate in number of units and power to complete the sawing with a water-cooled diamond edge saw blade or an abrasive wheel to the required dimensions and at the required rate. The Contractor shall provide at least one standby saw in good working order. An 5−2 ample supply of saw blades shall be maintained at the site of the work at all times during sawing operations. The Contractor shall provide adequate artificial lighting facilities for night sawing.
d.Forms. Straight side forms shall be made of a metal having a thickness of not less than 7/32-inch and shall be furnished in sections not less than 10 feet in length. Forms shall have a depth equal to or greater than the prescribed edge thickness of the concrete, without horizontal joint, and a base width equal to or greater than the depth of the forms. Flexible or curved forms of proper radius shall be used for curves of 100-foot r adius or less. Flexible or curved forms shall be of a design acceptable to the Engineer. Forms shall be provided with adequate devices for secure setting so that when in place they will withstand, without visible spring or settlement, the impact and vibration of the consolidating and finishing equipment. Flange braces shall extend outward on the base not less than two-thirds the height of the form. Forms with battered top surfaces, and bent, twisted, or broken forms shall be removed from the work. Repaired forms shall not be used until inspected and approved by the Engineer. Built-up fo rms shall not be used except where the total area of pavement of any specified thickness on the project is less than 2,000 square yards. The top face of the form shall not vary from a true plane more than 1/8-inch in 10 feet, and the upstanding leg shall not vary more than 1/4-inch. The forms shall contain provisions for locking the ends of abutting form sections together tightly, and for secure setting. 501.03.3 Preparation of Grade. After the roadbed has been graded and compacted to meet the density requirements of Subsection 301.03.2 of these Specifications, the grade shall be trimmed approximately to correct elevation, extending the work at least 2 feet beyond each edge of the proposed concrete pavement or base. 501.03.4 Setting Support.
a.Base Support. The foundation under the forms shall be hard and true to grade so that the form, when set, will be firmly in contact for its whole length and at the specified grade.
b.Form Setting. Forms shall be set sufficiently in advance of the point where concrete is being placed. Forms shall be staked into place with not less than 3 pins for each 10-foot section. A pin shall be placed at each side of every joint. Form sections shall be tightly interlocked, free from play or movement in any direction. The forms sha ll not deviate from true li ne by more than 1/4-inch at any point. No excessive settlement or springing of forms under the finishing machine will be tolerated. Forms shall be cleaned and oiled prior to the placing of concrete.
c.Grade and Alignment. The alignment and grade elevations of the forms shall be checked and corrections made by the Contractor bef ore placing the concrete. When any form has been disturbed or any grade has become unstable, the form shall be reset and rechecked. 501.03.5 Conditioning of Subgrade or Base Course. When side forms have been securely set to grade, the subgrade or base course shall be brought to proper cross section. High areas shall be trimmed to proper elevation. Low areas may be filled and compacted to a condition similar to that of surrounding grade, or filled with concrete integral with the pavement. The finished grade shall be maintained in a smooth and compacted condition until the pavement is placed. Unless waterproof subgrade or base course cover material is specified, the subgrade or base course shall be uniformly moist when the concrete is placed. If it subsequently becomes too dry, the subgrade or base course shall be sprinkled, but the method of sprinkling shall not be such as to form mud or pools of water. 5−3501.03.6 Placing Concrete. Concrete shall not be placed on soft, muddy, or frozen subgrade or subbase. Also, concrete shall not be placed when subgrade is frozen under adjacent pavement which is to remain in place. The concrete shall be deposited on the grade in such manner as to require as little rehandling as possible. Unless truck mixers, tr uck agitators, or nonagitating hauling equipment are equipped with means for discharge of concrete without segregation of the materials, the concrete shall be unloaded into an approved spreading device and mechanically spread on the grade in such manner to prevent segregation of the materials. Placing shall be continuous between transverse joints without the use of intermediate bulkheads. Necessary hand spreading shall be done with shovels, not rakes. Workmen shall not be allowed to walk in the freshly mixed concrete with boots or shoes coated with earth or foreign substances. Where concrete is to be placed adjoining a previously constructed lane of pavement and mechanical equipment will be operated upon the exis ting lane of pavement, that pavement shall meet the minimum flexural strength of 525 pounds per square inch when tested by the third-point method in accordance with AASHTO T97. If only finishing equipment is carried on the existing lane, paving in adjoining lanes may be permitted after three days. Concrete shall be thoroughly consolidated against and along the faces of all forms and along the full length and on both sides of all joint asse mblies, by means of internal vibrators inserted in the concrete. Vibrators shall not be permitted to come in contact with a joint assembly, the grade, reinforcement, or a side form. In no case shall the vibrator be operated longer than 10 seconds in any one location. The vibration shall be of sufficient duration to thoroughly consolidate the concrete but not so long as to produce segregation. Concrete shall be deposited as near to expansion and contraction joints as possible without disturbing them, but shall not be dumped from the discharge bucket or hopper onto a joint assembly unless the hopper is well centered on the joint assembly. Should any concrete materials fall on or be worked into the surface of a completed slab, they shall be removed immediately by approved methods. 501.03.7 Test Specimens. The Contractor shall furnish the concrete necessary for casting test beams and cylinders. The beams shall be cured by a designated method as specified for the pavement according to AASHTO T23. 501.03.8 Strike-off of Concrete and Placement of Reinforcement. Following the placing of the concrete, it shall be struck off to conform to the cross section shown on the Plans and to an elevation such that when the concrete is properly consolidated and finished, the surface of the pavement will be at the elevation shown on the Plans. When reinforced concrete pavement is placed in two layers, the entire width of the bottom layer shall be struck off to such length and depth that the sheet of fabric or bar mat may be laid full length on the concrete in its final position without further manipulation. The reinforcement shall t hen be placed directly upon the concrete, after which the top layer of the concrete shall be placed, struck off and screeded. Any portion of the bottom layer of concrete which has been placed more than 30 minutes without being covered with the top layer shall be removed and replaced with freshly mixed concrete at the Contractor's expense. When reinforced concrete is placed in one layer, the reinforcement may be positioned in advance of concrete placement or it may be placed in plastic concrete, after spreading by mechanical or vibratory means. The surface of reinforcing steel shall be free from any material which could impair bond of the steel with the concrete, all in accordance with the applicable requirements of SECTION 5−4 808; CAST-IN-PLACE STRUCTURE CONCRETE MASONRY , of these Specifications.
501.03.9 Joints. Joints shall be constructed of the type and dimensions, and at the locations
required by the Plans or Special Provisions.
a.Longitudinal Joint. Longitudinal sawed joints shall be cut by means of approved concrete saws to the depth, width and line shown on the Plans. Suitable guide lines or devices shall be used to assure cutting the longitudinal joint on the true line as shown on the Plans. The longitudinal joint shall be sawed before the end of the curing period and before any equipment or vehicles are allowed on the pavement. The sawed area shall be thoroughly cleaned and, if required, the joint shall immediately be filled with sealer.
b.Transverse Expansion Joints. The expansion joint filler s hall be continuous from form to form, shaped to the subgrade and to the keyway along the form. Preformed joint filler shall be furnished in lengths equal to the pavement width or equal to the width of one lane. Damaged or repaired joint filler shall not be used unless approved by the Engineer. The expansion joint filler shall be held in a vertical position. An approved installing bar, or other device, shall be used if required to secure preformed expansion joint filler at the proper grade and alignment during placing and finishing of the concrete. Finished joints shall not deviate more than 1/4-inch in the horizontal alignment from a straight line. If joint fillers are assembled in sections, there shall be no offsets between adjacent units. No plugs of concrete shall be permitted anywhere within the expansion space.
c.Transverse Contraction Joints. Transverse contraction joints shall consist of planes of weakness created by cutting grooves in the su rface of the pavement and, when shown on the Plans, shall include load transfer assemblies.
1.Sawed Contraction Joints shall be created by sawing grooves in the surfaces of the pavement or base to the dimensions and at the spacing and lines shown on the Plans with an approved concrete saw. After each joint is sawed, the saw cut and adjacent concrete surface shall be thoroughly cleaned. If curing blankets are used they shall be remov ed from the pavement only at the location(s) where a joint is to be sawed and only a sufficient width to allow the cut to be made. As soon as the cut has been made curing material shall be replaced. In no case shall either the top or edges of concrete be left unprotected for more than one-half hour. Sawing of the joints shall commence as soon as the concrete has hardened sufficiently to permit sawing without excessive raveling, usually 4 to 24 hours. All joints shall be sawed before uncontrolled shrinkage cracking takes place. If necessary, the sawing operations shall be carried on during the day and night, regardless of weather conditions. The sawing of any joint shall be omitted if a crack occurs at or near the joint location prior to the time of sawing. Sawing shall be discontinued when a crack develops ahead of the saw. The pavement within the lane where cracks occur shall be removed to the full width of the lane and replaced. The minimum lane length of pavement replacement shall be 6 feet. If cracking occurs on both sides of the same joint, the dowel assembly and a minimum of 3 feet on each side of the joint shall be removed and replaced, all at the Contractor's expense. In general, all joints should be sawed in sequence. All contraction joints in lanes adjacent to previously constructed lanes shall be sawed before uncontrolled cracking occurs. If extreme condi- 5−5tions exist which make it impractical to prevent e rratic cracking by early sawing, the contraction joint groove shall be formed prior to initial set of concrete.
2.Transverse Construction Joints shall be constructed when there is an interruption of more than 30 minutes in the concreting operations. No transverse joint shall be constructed within 10 feet of an expansion joint, contraction joint, or plane of weakness. If sufficient concrete has not been mixed at the time of interruption to form a slab at least 10 feet long, the excess concrete back to the last preceding joint shall be removed and disposed of.
3.Load Transfer Devices . Dowels, when used, shall be held in position parallel to the surface and centerline of the slab by a metal device that is left in the pavement. The dowels shall be thoroughly coated with an approved lubricant to prevent the concrete from binding to that portion of the dowel. An approved metal dowel cap or sleeve shall be furnished for each dowel bar used with the expansion joints. The caps or sleeves shall fit the dowel bar tightly and the closed end shall be watertight. In lieu of using dowel assemblies at contraction joints, dowel bars may be placed in the full thickness of pavement by a mechani cal device approved by the Engineer.
501.03.10 Final Strike-off, Consolidation and Finishing of Concrete Pavement.
a.Sequence. The sequence of operations shall be the strike-off and consolidation; machine finishing; floating; straightedging; and texturing. Following the placement of concrete, it shall be struck off to conform to the cross section indicated on the Plans and to an elevation such t hat once the concrete is properly consolidated and finished, the surface of the pavement will be at the elevation indicated on the Plans. In general, the addition of surficial water to the surface of the concrete to assist in finishing operations will not be permitted. If the application of water to the surface is permitted, it shall be applied as a fog spray by means of approved spray equipment.
b.Finishing at Joints. The concrete adjacent to joints shall be compacted or firmly placed without voids or segregation against the joint material, also under and around all load transfer devices, joint assembly units, and other features designed to extend into the pavement. Concrete adjacent to joints shall be mechanically vibrated as required in Subsection 501.03.6 . After the concrete has been placed and vibrated adjacent to the joints as required in Subsection 501.03.6 , the finishing machine shall be brought forward, operating in a manner to avoid damage or misalignment of joints. If uninterrupted operation of the finishing machine, to, over, and beyond the joints causes segregation of concrete, damage to, or misalignment of the joints, the finishing machine shall be stopped when the front screed is approximately 8 inches from the joint. Segregated concrete shall be removed from in front of and off the joint; the front screed shall be lifted and set directly on top of the joint and the forward motion of the finishing machine resumed. When the second screed is close enough to permit the excess mortar in front of it to flow over the joint, it shall be lifted and carried over the joint. Thereafter, the finishing machine may be run over the joint without lifting the screeds, provided there is no segregated concrete immediately between the joint and the screed or on top of the joint. 5−6 c. Machine Finishing.
1.Nonvibratory Method. The concrete shall be distributed or spread as soon as placed. As soon as the concrete has been placed, it shall be struck off and screeded by an approved finishing machine. The machine shall go over eac h area of pavement as many times and at such intervals as necessary to give the proper compac tion and to leave a surface of uniform texture. Excessive operation over a given area shall be avoi ded. The tops of the forms shall be kept clean by an effective device attached to the machine and the travel of the machine on the forms shall be maintained true without lift, wobbling, or other variation tending to affect the precision finish. During the first pass of the finishing machine, a uniform ridge of concrete shall be maintained ahead of the front screed for its entire length.
2.Vibratory Method. When vibration is specified, vibrators for full width vibration of concrete paving slabs shall meet the requirements in Subsection 501.03.2, Para. b . If uniform and satisfactory density of the concrete is not obtained by the vibratory method at joints, along forms, at structures, and throughout the pavement, the Contractor will be required to furnish equipment and methods which will produce pavement conforming to the Specifications. All the provisions in Para. c.1, above, not in conflict with the provisions for the vibratory method shall govern.
d.Hand Finishing. Unless otherwise specified, hand finishing methods will not be permitted except under the following conditions: In the event of breakdown of the mechanical equipment, hand methods may be used to finish the concrete already deposited on the grade when the breakdown occurs. Narrow widths or areas of irregular dimensions where operations of the mechanical equipment is impractical may be finished by hand methods. Concrete, as soon as placed, shall be struck off and screeded. An approved portable screed shall be used. A second screed shall be provided for striking off the bottom layer of concrete, if reinforcement is used. The screed for the surface shall be at least 2 f eet longer than the maximum width of the slab to be struck off. It shall be of approved design, sufficiently rigid to retain its shape, and be constructed either of metal or of other suitable material shod with metal. Consolidation shall be attained by the use of a suitable vibrator or other approved equipment. If necessary, this shall be repeated until the surface is of uniform texture, true to grade and cross section, and free from porous areas.
e.Floating. After the concrete has been struck off and consolidated, it shall be further smoothed, trued, and consolidated by means of a longitudinal float, using one of the following methods as specified or permitted:
1.Hand Method. The hand-operated longitudinal float shall be not less than 12 feet in length and 6 inches in width, properly stiffened to prevent flexibility and warping. The longitudinal float, operated from foot bridges resting on the side forms and spanning but not touching the concrete, shall be worked with a sawing motion, while held in a floating position parallel to the road centerline, and passing gradually from one side of the pavement to the other. Movement ahead along the centerline of the pavement shall be in successive advances of not more than one-half the 5−7length of the float. Any excess water or soupy material shall be wasted over the side forms on each pass.
2.Mechanical Method. The mechanical longitudinal float shall be of a design approved by the Engineer, and shall be in good working condition. The tracks from which the float operates shall be accurately adjusted to the required crown. The float shall be accurately adjusted and coordinated with the adjustments of the transverse finishing machine so that a small amount of mortar is carried ahead of the float at all times. The forward speed shall be adjusted so that the float will lap the distance specified by the Engineer on each transverse trip. The float shall pass over each area of pavement at least two times, but excessive operation over a given area will not be permitted. Any excess water or soupy material shall be wasted over the side forms on each pass.
3.Alternative Mechanical Method. As an alternative to t he Mechanical Method described above, the Contractor may use a machine composed of a cutting and smoothing float, or floats, suspended from and guided by a rigid frame. The fram e shall be carried by four or more visible wheels riding on, and constantly in contact with, the side forms. If necessary, following one of the preceding me thods of floating, long-handled floats having blades not less than 5 feet in length and 6 inches in width may be used to smooth and fill in open textured areas in the pavement. Long-handled floats shall not be used to float the entire surface of the pavement in lieu of, or supplementing, one of the preceding methods of floating. When strike-off and consolidation are done by the hand methods and the crown of the pavement will not permit the use of the longitudinal float, the surface shall be floated transversely by means of the long-handled float. Care shall be taken not to work the crown out of the pavement during the operation. After floating, any excess water and laitance shall be removed from the surface of the pavement by a straightedge 10 feet or more in length. Successive drags shall be lapped one-half the length of the blade.
f.Straightedge Testing and Surface Correction. After the floating has been completed and the excess water removed, but while the concrete is still plastic, the surface of the concrete shall be tested for trueness with a 10-foot straightedge. For this purpose, the Contractor shall furnish and use an accurate 10-foot straightedge swung from handles 3 feet longer than one-half the width of the slab. The straightedge shall be held in contact with the surface in successive positions parallel and perpendicular to the road centerline and the whole area gone over from one side of the slab to the other as necessary. Adv ance along the road shall be in successive stages of not more than one-half the length of the straight edge. Any depressions found shall be immediately filled with freshly mixed concrete, struck off, consolidated, and refinished. High areas shall be cut down and refinished. Special attention shall be given to assure that the surface across joints meets the requirements for smoothness. Straightedge test ing and surface corrections shall continue until the entire surface is found to be free from obs ervable departures from the straightedge and the slab conforms to the required grade and cross section.
g.Final Finish. The final finish shall be specified or shown on the Plans and shall consist of one of the three finishes described as follows:
1.Broom Finish . If the surface texture is to be a broom finish, it shall be applied when the water sheen has practically disappeared. The broom shall be drawn from the center to the edge of the pavement with adjacent strokes slightly overlapping. The brooming operation shall be so executed that the corrugations produced in the surface shall be uniform in appearance and not 5−8 more that 1/8-inch in depth. Brooming shall be completed before the concrete is in such condition that the surface will be torn or unduly roughened by the operation. The surface thus finished shall be free from rough and porous areas, irregularities, and depressions, resulting from improper handling of the broom. Brooms shall be of the qua lity, size, and construction and be so operated as to produce a surface finish meeting the approval of the Engineer. Subject to satisfactory results being obtained and approval of the Engineer, the Contractor will be permitted to substitute mechanical brooming in lieu of the manual brooming as herein described.
2.Belt Finish . If the surface texture is to be a belt finish, when straightedging is complete and water sheen has practically disappeared and just before the concrete becomes nonplastic, the surface shall be belted with a 2-ply canvas belt not less than 8-inches wide and at least 3 feet longer than the pavement width. Hand belts shall have suitable handles to permit controlled, uniform manipulation. The belt shall be operated with short strokes transverse to the road centerline and with a rapid advance parallel to the centerline.
3.Drag Finish . If the surface texture is to be a drag finish, a drag shall be used which shall consist of a seamless strip of damp burlap or cotton fabric, which shall produce a uniform surface of gritty texture after dragging it longitudinally along the full width of pavement. For pavement 16 feet or more in width, the drag shall be mounted on a bridge which travels on the forms. The dimensions of the drag shall be such that a strip of burlap or fabric at least 3 feet wide is in contact with the full width of pavement surface while the drag is used. The drag shall consist of not less than 2 layers of burlap with the bottom layer approximately 6 inches wider than the upper layer. The drag shall be maintained in such condition that the resultant surface is of uniform appearance and reasonably free from grooves over 1/8-inch in depth. Drags shall be maintained clean and free from encrusted mortar. Drags that cannot be cleaned shall be discarded and new drags substituted.
h.Edging at Forms and Joints. After the final finish, but before the concrete has taken its initial set, the edges of the pavement along each side of each slab, and on each side of transverse expansion joints, formed joints, transverse constr uction joints, and emergency construction joints, shall be worked with an approved tool and rounded to the radius required by the Plans. A well-defined and continuous radius shall be produced and a smooth, dense mortar finish obtained. The surface of the slab shall not be unduly disturbed by tilting of the tool during use. At all joints, any tool marks appearing on the slab adjacent to the joints shall be eliminated by brooming the surface. In doing this, the rounding of the corner of the sl ab shall not be disturbed. All concrete on top of the joint filler shall be completely removed. All joints shall be tested with a straightedge before the concrete has set, and corrections made if one side of the joint is higher than the other or if they are higher or lower than the adjacent slabs.
i.Concrete Base. In the case of concrete base, the above requirements for finishing and/or longitudinal floating are waived. 501.03.11 Surface Test.
a.Concrete Pavement. As soon as the concrete has hardened sufficiently, the pavement surface shall be tested with an approved 10-foot straightedge furnished by the Contractor. Areas showing high spots of more than 1/4-inch but not exceeding 1/2-inch in ten feet shall be marked 5−9and immediately ground down with an approved grinding t ool to an elevation where the area or spot will not show surface deviations in excess of 1/4-inch when tested with a 10-foot straightedge. Where the departure from correct cross section exceeds ½-inch, the pavement shall be removed and replaced by and at the expense of the Contractor. Any area or section so removed shall be not less than 10 feet in length nor less than the full width of the lane involved. When it is necessary to remove and replace a section of pavement, any remaining portion of the slab adjacent to the joints that is less than 10 feet in length, shall also be removed and replaced.
b.Concrete Base. The surface of the concrete base shall be roughened by any means acceptable to the Engineer such as brooming, tinni ng, or burlap drag. The surface shall be finished so that there will be no deviation of more than 3/ 8-inch between any two contact points when tested with a 10-foot straightedge. 501.03.12 Curing. Immediately after the finishing operations have been completed and as soon as marring of the concrete will not occur, the entire surface of the newly placed concrete shall be cured in accordance with the applicable provisions of Subsection 601.03.8 of these Specifications.
501.03.13 Removing Forms. Unless otherwise provided, forms shall not be removed from freshly
placed concrete until it has set for at least 12 hours, except auxiliary fo rms used temporarily in widened areas. Forms shall be removed carefully so as to avoid damage to the pavement. After the forms have been removed, the sides of the slab shall be cured as outlined in one of the methods indicated above. Major honeycombed areas will be considered as defective work and shall be removed and replaced. Any area or section so removed shall not be less than 10 feet in length nor less than full width of the lane involved. When it is necessary to remove and replace a section of pavement, any remaining portion of the slab adjacent to the joints that is less than 10 feet in length, shall also be removed and replaced. 501.03.14 Sealing Joints. If the joints are to be sealed, they shall be filled with joint sealing material before the pavement is opened to traffic, and as soon after completion of the curing period as is feasible. Just prior to sealing, each joint shall be thoroughly cleaned of all foreign material, including membrane curing compound and the joint faces shall be cleaned and surface dry when the seal is applied. Material for seal applied hot shall be stirred during heating so that localized overheating does not occur. The sealing material shall be applied to each joint opening to conform to the details shown on the Plans or as directed by the Engineer. The pouring shall be done in such a manner that the material will not be spilled on the exposed surfaces of the concrete. Any excess material on the surface of the concrete pavement shall be removed immediately and the pavement surface cleaned. The use of sand or similar material as a cover for the seal will not be permitted. Poured joint-sealing material shall not be placed when the air temperature in the shade is less than 50 OF, unless approved by the Engineer. When specified, preformed compression seals and lubricant adhesive shall conform to Subsection M.02.10.3 of these Specifications.
501.03.15 Protection of Pavement. The Contractor shall protect the pavement and its
appurtenances against both public traffic and traffic caused by his own employees and agents. 5−10 Any damage to the pavement, occurring prior to final acceptance, shall be repaired or the pavement replaced. 501.03.16 Opening to Traffic. The Engineer will decide when the pavement or base shall be opened to traffic. Pavement or base will not be opened to traffic until specimen beams have attained a flexural strength of 525 pounds per square inch when tested by the third-point method, in accordance with AASHTO T97. 501.03.17 Concrete Pavement-Slip Form Method. If the Contractor elects to use the slip-form method, the following provisions shall apply:
a.Grade. After the grade or base has been placed and compacted to the required density, the areas which will support the paving machine sha ll be cut to the proper elevation by means of a properly designed machine. The grade on which the pavement is to be constructed shall then be brought to the proper profile by means of a properly designed machine. If the density of the base is disturbed by the grading operations, it shall be corrected by additional compaction before concrete is placed. The grade should be constructed sufficiently in advance of the placing of the concrete. If any traffic is allowed to use the prepared grade, the grade shall be checked and corrected immediately ahead of the placing of the concrete.
b.Placing Concrete. The concrete shall be placed with an approved slip-form paver designed to spread, consolidate, screed, and float-fin ish the freshly placed concrete in such manner that a minimum of hand finish will be necessary to provide a dense and homogenous pavement in conformance with the Plans and Specifications. The machine shall vibrate the concrete for the full width and depth of the strip of pavement being placed. Such vibration shall be accomplished with vibrating tubes or arms working in the concrete. The sliding forms shall be rigidly held together laterally to prevent spreading of the forms. The forms shall trail behind the paver for such a distance that no appreciable slumping of the concrete will occur, and that necessary final finishing can be accomplished while the concrete is still within the forms. The concrete shall be held at a uniform consistency, having a slump of not more than 2 inches. The slip-form paver shall be operated with as nearly a continuous forward movement as possible and all operations of mixing, delivering and spreading concrete shall be so coordinated as to provide uniform progress with stopping and starting of the paver held to a minimum. If, for any reason, it is necessary to stop the forward movement of the paver, the vibratory and tamping elements shall also be stopped immediately. No tractive force shall be applied to the machine, except that which is controlled from the machine.
c.Finishing. The surface smoothness and texture shall meet the requirements of Subsection 501.03.10 and Subsection 501.03.11 .
d.Curing. Unless otherwise specified, curing shall be done in accordance with one of the methods included in Subsection 601.03.8 . The curing media shall be applied at the appropriate time and shall be applied uniformly and completely to all surfaces and edges of the pavement.
e.Joints. All joints shall be constructed in accordance with Subsection 501.03.9 and sealed in accordance with Subsection 501.03.14 .
f.Protection Against Rain. In order that the concrete may be properly protected against the effects of rain before the concrete is sufficiently hardened, the Contractor will be required to 5−11have available at all times materials for the protection of the edges and surface of the unhardened concrete. Such protective materials shall consist of standard metal forms or wood plank having a nominal thickness of not less than 2 inches and a nominal width of not less than the thickness of the pavement at its edge for the protection of the pavement edges, and covering material such as burlap or cotton mats, curing paper, or plastic sheeting material for the protection of the surface of the pavement. When rain appears imminent, all paving operations shall stop and all available personnel shall begin placing forms against the sides of the pavement and covering the surface of the unhardened concrete with the protective covering. 501.03.18 Tolerance in Pavement or Base Thickness. The thickness of the pavement or base will be determined by the average caliper measur ement of cores tested in accordance with AASHTO T148. For the purpose of establishing an adjusted unit price for the pavement or base, units to be considered separately are defined as 1,000 linear feet of pavement in each traffic lane starting at the end of the pavement bearing the smaller station number. The last unit in each lane shall be 1,000 feet plus the fractional part of 1,000 feet remaining. One core will be taken at random by the Department in each unit. When the measurement of the core from a unit is not deficient more than 3/8-inch from the Plan thickness, full payment w ill be made. When such measurement is deficient more than 3/8-inch and not more than 1 inch from the Plan thickness two additional cores at intervals of not less than 300 feet will be taken and used in the average thickness for that unit. An adjusted unit price as provided in Subsection 501.05.2 will be paid for the unit represented. Other areas such as intersections, entrances, crossovers, ramps, etc., will be considered as one unit and the thickness of each unit will be determined separately. Small irregular unit areas may be included as part of another unit. At such points as the Engineer may select in each unit, one core will be taken for each 1,000 square yards of base or pavement, or fraction thereof, in the unit. If the core so taken is not deficient more than 3/8-inch from the Plan thickness, full payment will be made. If the core is deficient in thickne ss by more than 3/8-inch but not more than 1 inch from the Plan thickness, two additional cores will be taken from the area represented and the average of the three cores determined. If the average measurement of these three cores is not deficient more than 3/8-inch from the Plan thi ckness, full payment will be made. If the average thickness of the three cores is deficient more than 3/8-inch but not more than 1 inch from the Plan thickness, an adjusted unit price as provided in Subsection 501.05.2 will be paid for the area represented by these cores. In calculating the average thickness of the bas e, measurements which are in excess of the specified thickness by more than 3/8-inch will be considered as the specified thickness plus 3/8-inch, and measurements which are less than the specif ied thickness by more than 1 inch will not be included in the average. When the measurement of any core is less than the Plan thickness by more than 1 inch, the actual thickness of the base in this area will be determined by taking additional cores at 10-foot intervals parallel to the centerline in each direction from the affected location until in each direction a core is found which is not deficient by more than 1 inch. Areas found deficient in thickness by more than 1 inch shall be evaluated by the Engineer. If the Engineer decides that the deficient areas should be removed, they shall be removed and replaced with concrete of the thickness shown on the Plans. Exploratory cores for deficient thickness will not be used in averages for adjusted unit price. 5−12 The method of establishing the adjusted unit price for pavement based on the measurement of cores is specified below in Subsection 501.05.2 .
501.04 METHOD OF MEASUREMENT. "Portland Cement Concrete Pavement" and "Portland
Cement Concrete Base" will be measured by the num ber of square yards of each actually provided in accordance with the Plans and/or as directed by the Engineer. The width for measurement will be the width of the pavement shown on the typical cross section of the Plans, additional widening where called for, or as otherwise directed in writing by the Engineer. The length will be measured horizontally along the centerline of each roadway or ramp.
501.05 BASIS OF PAYMENT. 501.05.1 General. The accepted quantities of "Portland Cement Concrete Pavement" and
"Portland Cement Concrete Base" will be paid for at their respective contract unit prices per square yard as listed in the Proposal. The prices so-stated constitute full and complete compensation for all labor, materials and equipment, including reinforcing steel, dowels, joint material, and all incidentals required to finish the work, complete and accepted by the Engineer. 501.05.2 Price Adjustments. Where the average thickness of pavement is deficient in thickness by more than 3/8-inch, but not more than 1 inch, payment will be made at an adjusted price as specified in the following table: Concrete Pavement Deficiency Deficiency in Thickness Proportioned Part Determined by Cores of Contract Unit Inches Price Allowed __________________________ _____________________ 0 to 3/8 100 percent 3/8 to 1/2 80 percent 1/2 to 5/8 72 percent 5/8 to 3/4 68 percent 3/4 to 7/8 57 percent 7/8 to 1 50 percent When the thickness of pavement or base is deficient by more than one inch and the judgment of the Engineer is that the area of such deficient pavement or base should not be removed and replaced, there will be no payment for the area so-retained. No additional payment over the contract uni t price will be made for any pavement or base which has an average thickness in excess of that shown on the Plans. 5−13SECTION 502 FULL DEPTH CLEANING AND SEALING OF JOINTS AND CRACKS TWO AND ONE HALF (2½) INCHES NOMINAL WIDTH OR LESS IN PORTLAND CEMENT CONCRETE PAVEMENT
502.01 DESCRIPTION . This work consists of performing all operations required for cleaning and
sealing cracks and joints in existing Portland cem ent concrete pavement of 2½-inch nominal width or less at the locations indicated on the Plans or as directed by the Engineer , all in accordance with these Specifications. 502.02. MATERIALS.
a.Joint Seal. Poured joint seal material shall be hot poured asphalt rubber compound conforming to the requirements of AASHTO M173 and approved by the Engineer.
502.03 CONSTRUCTION METHODS. 502.03.1 Equipment. Equipment shall be subject to the approval of the Engineer and maintained
in satisfactory working condition at all times.
a.Cutter. Equipment for reshaping cracks shall be a vertical spindle type cutter.
b.Air Compressor. Air compressors shall be portable and capable of furnishing not less than 100 cubic feet of air per minute at not less than 90 pounds per square inch pressure at the nozzle. The compressor shall be equipped with traps that will maintain the compressed air free of oil and water.
c.Self-propelled Sweeper. A small self-propelled sweeper designed especially for use in cleaning highway and airfield pavements shall be used to remove debris, dirt, and dust from joints or cracks in concrete pavement.
d.Hand Tools shall consist of brooms, wire brushes, shovels, metal bars with chisel shaped ends, and any other tools which may be used to accomplish this work.
e.Melting Kettle. The unit used to melt the joint sealing compound shall be a double boiler, indirect fired type. The space between the inner and outer shells shall be filled with a suitable heat transfer oil or substitute having a flash point of not less than 550 OF. The kettle shall be equipped with a satisfactory means of agitating the joint sealer at all times. This may be accomplished by continuous stirring with mechanically operated paddles or by a continuous circulating gear pump attached to the heating unit. The kettle must be equipped with thermostatic control calibrated between 200 OF and 550OF.
f.Application System. The joint seal shall be placed by hot extrusion with a wand type instrument. The system shall include a flow control valve which allows all cracks to be filled to refusal. 502.03.2 Preparation of Cracks and Joints. All transverse and longitudinal joints and any cracks shall be sealed. Just prior to sealing, each joint or crack shall be thoroughly cleaned to the full
Source: Rhode Island Standard Specifications (Bluebook), 2024 Edition. Pages 232–245 of 826.