540BONDED CONCRETE OVERLAY OF ASPHALT-SURFACED PAVEMENT

PAVEMENT

540.1DESCRIPTION —This work is the construction of a Portland cement concrete overlay with a

thickness of 4 to 8 inches and is bonded to an existing asphalt-surfaced pavement. It includes asphalt surface preparation, overlay construction, construction of transitions, joint sawing and sealing, and other construction details, as indicated.

540.2MATERIAL—

• Class AA Cement Concrete—Section 704 except, revise the Table A Maximum Water Cement Ratio by weight to 0.42. If the maturity method is intended to be used, correlate the degree-hours of cure to compressive strengths in accordance with PTM No. 640 except, at time intervals of 8 hours, 1, 7, 28 and 56 days.

• Expansion Joint Filler. Section 705.1

• Tape Bond Breaker. An acceptable self-adhesive tape with width matching that of the sealant reservoir.

• Joint Backing Material. Section 705.8

• Longitudinal Joint Material. Section 705.2, for use in transition areas only

• Load Transfer Units. Sections 705.3(a) and (b), for use in transition areas only

• Joint Sealing Material. Section 705.4(a). Self-leveling, Section 705.4(b), or (c)

• Concrete Curing Material. Section 711.1 and 711.2(a), ASTM C309 Type 2

• Concrete Covering Material. Section 711.1

• Concrete Admixtures. Section 711.3

• Class 4 Geotextile, Non-woven. Section 735, for use in transition areas only

• Epoxy Bonding Compound. Section 706.1 Type V

• Pre-Mixed Non-Shrink Grout. An approved type as listed in Bulletin 15

540.3CONSTRUCTION—Section 501.3, modified as follows:

to this work, including, but not limited to, surface preparation, the timing and sequence of the work, including timing of mixing, hauling, placing, curing, monitoring of concrete temperature, joint sawing, and sampling and strength testing or evaluation for opening to traffic. Indicate variations in timing of activities in response to anticipated variations in air temperature at the time of placement. Submit the QC Plan for the Representative’s review before the start of the project . Do not begin construction - related work until the QC Plan has been accepted.

indicated in the plans as specified in Section 492. Instead of replacing unsound pavement as specified in Section 492.3(c) with asphalt materials, replace with Class AA Cement Concrete in conjunction with the placement of the concrete overlay. Saw cutting and chipping with pneumatic hammers may be used to remove areas inaccessible by a milling machine. Clean and f ill in cracks greater than 3/4 inches with non-shrink grout or other material approved by the Department which will enable bond to the concrete overlay before pavement surface cleaning. No standing waters hould remain on the surface after the milling operation. If standing water occurs, immediately provide measures, acceptable to the Department, to drain the water from the milled surface. Completely clean the milled pavement surface to completely remove all loose debris . Protect the cleaned and prepared surface from oil or grease drippings from compressors, concrete trucks, spreaders, pavers, etc. Remove all deleterious materials before overlaying. Conduct final cleaning of the surface no more than 30 minutes before the placement of the concrete overlay to remove loose material and debris. If using a compressed air stream, ensure that it is free of oil, moisture, and other potential contaminants, and that has a minimum pressure of 100 pounds per square inch measured at the source. Immediately before placing the concrete overlay, ensure the asphalt surface is less than 120F. Fog- misting, protective covers or blankets will be allowed to achieve the proper condition of the surface , however, do not allow any standing water or moisture to remain on the pavement surface.

is indicated, develop a joint layout plan to be accepted by the Department and lay out joints before placement of concrete. Avoid placing longitudinal joints in the wheel paths. In general, maximum panel dimensions should not exceed 18 times the concrete overlay thickness, and the length of the longer panel dimension divided by the shorter panel dimensio n should not exceed 1.5. The Representative may allow or require slight deviations from nominal panel dimensions to match joints in adjacent pavement or structures, or to avoid the construction of panels with dimensions or shapes that would otherwise be subject to premature cracking. Sawing is the only acceptable technique for creating concrete overlay joints. Saw joints as soon as concrete has sufficiently hardened to allow sawing without excessive raveling resulting from the sawing operation and to prevent random cracking. The use of “early entry” saws is recommended. FHWA’s HIPERPAV or similar software approved by the Department may be used in determining a project - specific sawing window. If necessary, conduct sawing operations continuously, both day and night, regardless of weather conditions. Saw joints with a green cut saw to a depth of D/3 and a minimum width of 1/8 inch. If initial saw cuts do not extend through the sl ab edge to avoid “blowouts” or edge damage of green concrete, extend these cuts through the edge as soon as it can be done without causing damage. Omit sawing if a crack occurs at or within 1.5 feet of a joint location, before or during sawing, and address as specified in Section 5 90. Do not seal joints at this time. Clean joints of all deleterious material after sawing. If pavement is cured by means other than white -pigmented, liquid membrane -forming curing compound, remove curing materials from overlay, at the location where a joint is to be cut. Remove only sufficient covering to provide space necessary for sawing joints. As soon as the joint is made, replace the covering. The maximum time period allowed for pavement curing covers to be removed is 1/2 hour. If white-pigmented, liquid membrane-forming curing compound is used, cure the joint area, as specified in Section 501.3(l)1.c.

indicated. In areas where transitions contain existing treated base course or concrete pavement directly below the overlay, place geotextile as a debonding layer as specified in Section 212.

• Replace the first sentence of Section 501.3(l)1 with the following:

Apply curing materials after finishing and texturing, and within 30 minutes of the dissipation of bleed water. Maintain the curing materials until the pavement has achieved sufficient strength for opening to traffic as specified in Section 540.3(q).

• Add the following paragraphs at the end of Section 501.3(l)1:

Provide adequate insulating blankets to prevent rapid heat loss if the air temperature is 45F or less. Insulation may be removed when the air temperature exceeds 45F or when the average compressive strength of the concrete exceeds 3,000 pounds per square inch. Remove insulation in a manner such that the rate of temperature change at the concrete surface does not exceed 40F within any 1-hour period. Concrete that experiences a higher rate of temperature change will be considered defective. The application or removal of insulation covers may be controlled by the use of maturity method as specified in Section 540.3(q), with full removal of insulation allowed after the minimum required degree-hours of curing has been accumulated at the top of the slab.

• Replace the second sentence of the second paragraph of Section 501.3(l)1.c with the following: Apply curing compound homogenously to provide a uniform, solid white opaque coverage on all exposed concrete surfaces. Apply at a minimum rate of 1 gallon (± 0.1 gallon) per 125 square feet or as specified by the manufacturer’s recommendations, whichever is greater. If conditions warrant, the curing compound can be applied in two equal rates of application, with the first applied as stated previously and the second applied immediately after sawing operations have been completed. Joint faces must be protected from exposure to curing compound or cleaned thoroughly before sealant installation.

sealant material in accordance with the manufacturer’s recommendations and as specified in Section 501.3(n).

Section 506.3(o)

The Representative will determine when pavement will be opened to traffic based on when the concrete attains the minimum required compressive strength of 3,000 pounds per square inch as measured either by compressi ve strength testing of cylinders in accordance with PTM No. 604 or by the maturity method in accordance with AASHTO T 413.

Before final acceptance of each phase of the project, proceed as follows:

• The Department will divide the concrete overlay pavement into lots representing not more than 3,000 square yards of pavement in each traffic lane. Include ramps in a separate lot (s). The Inspector will select one coring location at random within each lot according to PTM No. 1. Drill cores according to PTM No. 606 and in the presence of the Inspector. For projects at intersections or less than 3,000 square yards, drill two cores. Thoroughly clean the vertical surface of the core hole of laitance and loose and foreign material. Fill the holes with the mixture used to construct the course and consolidate. As an alternative, use a premixed, non-shrink grout.

• Provide a measuring apparatus conforming to PTM No. 614. The Inspector will determine the core depth according to PTM No. 614.

• If any core measurement is deficient by more than 1/4 inch in required depth, drill additional cores in the presence of and for measurement by the Inspector. Drill the additional cores at 100 -foot intervals in both directions longitudinally from each deficient core, in the same traffic lane, until

the depth is no more than 1/4 inch deficient. Each core will represent the condition in the same traffic lane for a distance of 50 feet in both directions longitudinally.

• The Inspector will consider the pavement to be defective if any core measurement is deficient in required depth as indicated in Table B.

Unless otherwise directed in writing by the District Executive, remove and replace, at no cost to the Department, pavement that is: defective in construction or sawing of joints as specified in Section 540.3(i); defective in curing requirements as specified in Section 540.3(l); defective in surface tolerance, as specified in Section 501.3(o); defective in depth, as specified in Section 540.3(s); defective in air content, as specified in Section 704.1(c)3; defective in compressive strength as specified in Section 704.1(d), or showing surface defects resulting from the effects of freezing and thawing, rain, hail, improper final finish, or honeycombing. The minimum pavement removal and replacement will be one panel in length and width. Where deficiencies are exhibited in successive panels of pavement, remove and replace entire panels. After removal of defective pavement, reestablish replaced joints. If removing and replacing pavement defective in depth, start at the determined point of deficiency as determined by the Representative. Remove and replace defective work transversely for the full -lane width and longitudinally, until the pavement is not more than 1/4 inch deficient in depth, as specified in Section 540.3(s).

540.4MEASUREMENT AND PAYMENT—

Ownership of the milled material will be indicated by the selected item of work. The transition areas will be excluded.

This unit price includes all work associated with the construction of the concrete overlay except the cement concrete material and the profile milling. The price also excludes the concrete overlay transitions and the concrete pavement cores.

For producing the cement concrete needed for the overlay and delivering it to the jobsite. Pay quantity for the overlay will be computed based on the indicated depth and the placement area. An additional quantity, not to exceed 2% of the computed overlay q uantity, may be paid as compensation for the cost of cement concrete material needed to replace unsound pavement material removed as part of the profile milling operation. Excludes cement concrete material used in transition areas . Submit written request for additional compensation with justification . The justification should in dicate the cubic yardage of concrete delivered to the job site from delivery tickets and show a deduction for the volume of the overlay and the quantity of concrete wasted.

This unit price includes all associated items of work within the limits of the transitions.

The price includes the measuring apparatus, which remains the Contractor's property upon completion of the project. The Department will not pay for additional cores drilled when the depth is deficient by more than 1/4 inch.

cores, lot payment for both the bonded concrete overlay and the cement concrete material will be adjusted as specified in Table B.

TABLE B Adjustment for Depth Deficient in Depth Determined by Cores (inches) Payment Percent of Contract Unit Price, by Lot, Based on Nominal Overlay Depth (%) ≤ 4.00 inches 4.25 to ≤ 6.00 inches > 6.00 inches -0.25 to 0.00 100 100 100 -0.30 to -0.26 95 97 99 -0.35 to -0.31 85 90 95 -0.40 to -0.36 75 80 90 -0.45 to -0.41 65 70 85 -0.50 to -0.46 50 60 75 -0.60 to -0.51 Defective Work 50 65 -0.75 to -0.61 Defective Work Defective Work 50 > -0.75 Defective Work Defective Work Defective Work

place, unless otherwise directed in writing by the District Executive. When the District Executive directs that defective pavement be left in place, final payment for this pavement will be at 5% of the contract unit prices of the concrete overlay and the cement concrete.