Section 502 — Concrete Pavement Restoration
Description
502.01This work consists of concrete pavement restorati on.
Material
502.02Conform to the following Subsections: Epoxy mortar 725.14(a) Epoxy resin adhesives 725.12 Hydraulic cement 701.01 Non-shrink grout 701.04(b)(1) Polyurethane grout 725.14(c) Reinforcing steel 709.01 Sealants, fillers, and seals 712.01 Water for cementitious materials 725.01(a)
502.03General. Design the concrete mix according to Subsection 501.03. If colored concrete is required, submit preliminary samples of the colored concrete according to Subsection 601.03(b) .
502.04Equipment. Provide equipment conforming to the following:
(a)Water blaster. Provide a high- pressure water jet machine with at least 2500 pounds per square inch pressure and that can remove residual sealant, oil, or other foreign material in joints.
(b)Air compressors. Provide air compressors with a minimum nozzle pressure of 100 pounds per square inch and that can dislodge loose debris and dry joints and cracks.
(c)Grout plant. Provide a grout plant that consists of a positive displacement cement injection pump and a high- speed colloidal mill. Operate colloidal mill at speeds necessary t o make a homogeneous mixture. Provide an injection pump having a pressure capability of 275±25 pounds per square inch when pumping a grout slurry mixed to a 12- second flow cone time. Provide an injection pump that can continuously pump at a minimum rate of 1.5 gallons per minute. The system may be modified by adding a recirculating hose and valve at the discharge end of the pump. Produce grout through a meter or scale that can measur e the total day’s consumption. Provide hoses and fittings to produce a posi tive seal during grout injection.
(d)Drills. Provide drills that meet the following:
(1)Drills for pavement jacking. Provide rock drills that can drill straight holes through the concrete slab with a minimum diameter recommended by the grout manufacturer. Provid e rock drills weighing no more than 60 pounds that can drill with a downward pressure of no more than 200 pounds. Provide an auger to open clogged holes and existing pavement jacking holes.
(2)Drills for dowels and tie bars. Provide drills that can drill spec ified hole diameters for dowel bars or reinforcing steel tie bars. Provide drills for dowel bars that can drill holes that meet the vertical and horizontal tolerance of ±¼ inch along the centerline of the dowel with respect to a horizontal line that is perpendicular to the plane established by the joint. Operate equipment to prevent damage to the structural integrity of the existing slab.
(e)Surface diamond grinder. Provide power driven, self -propelled grinding equipment, specifically designed to improve smoothness and texture of concrete pavement with diamond blades. Provide equipment that:
(1)Cuts or planes at least 36 inches in width;
(2)Does not encroach on traffic outside of the work area; and
(3)Grinds the surface without causing spalling.
(f)Hydroblaster. Provide hydroblasting equipment conforming to Subsection 560.05.
(g)Cold planing (milling) machine. Provide a micro milling machine that does not exceed the bearing capacity of the concrete pavement and conforming to Subsection 413.02(b) .
(h)Slab stabilization testing. Provide the following testing equipment:
(1)A 2-axle truck with dual rear wheels. Load the rear axle to 18 kips evenly distributed between the wheel paths;
(2)Static load measuring gauges consisting of 4 gauges on 2-gauge mounts, 2 gauges per mount, that can detect slab movement under load; and
(3)A modified Benkelman beam or similar approv ed device.
(i)Polyurethane grout pump. Provide a grout pump that can inject high density polyurethane material through a drilled hole and beneath a slab and can control the flow rate of the material as required to stabilize and lift the slab. Provide control devices that can maintain proper temperature and proportionate mixing of polyurethane material according to the manufacturer’s recommendations.
(j)Shotblasting. Provide equipment with an air stream free of oil according to ASTM D4285 and that can remov e rust, oil, and other foreign material. Provide equipment meeting the requirements of ASTM D4259.
502.05Partial -Depth Patching (less than 4 inches in depth). This work consists of patching spalls, potholes, corner breaks, or other surface distresses in concret e pavement.
(a)Patch material. Use a polymer concrete conforming to Section 572 for patches less than or equal to 1½ inches deep. Use hydraulic cement concrete conforming to Section 501 for patches greater than 1½ inches deep.
(b)Patch area preparation. Extend the limits of repair at least 4 inches outside the deteriorated area. Saw vertically along the perimeter of the patch area, parallel to the existing joint, and to at least 1½ inches deep. Near vertical edges from milling or grinding machines are acceptable. Repair saw overcuts and nicks to adjacent pavement outside the perimeter of the repair area with noncorrosive, non-shrink grout. Break out concrete within the patch area to at least 1½ inches deep to expose sound concrete. Shot blast exposed concrete faces and reinforcing steel until free of rust and foreign material. Remove and replace deteriorated reinforcing steel. Clean patch area of loose particles, oil, dust, traces of asphalt concr ete, and other contaminants, using clean water under pressure or compressed air, no more than 24 hours before patching. If compressed air is used, provide a filter in the airline to ensure that the air is oil -free. Remove non -concrete shoulders adjacent to the patch longitudinally to the depth of the patch and to a maximum width of 12 inches to facilitate placing formwork. Dispose of the concrete according to Subsection 203.07.
(c)Placing concrete. For hydraulic cement concrete, remove shot blast residue immediately before placing the epoxy resin adhesive. Apply an epoxy resin adhesive according to the manufacturer’s recommendations. Delay hydraulic cement concrete placement until the epoxy becomes tacky. Place and conso lidate the concrete to eliminate voids at the interface of the patch and existing concrete. Place and consolidate hydraulic cement concrete according to Subsection 501.07. Place and consolidate polymer concrete according to Section 572 and methods recommended by the manufacturer.
(d)Joints. If a repair area abuts a working joint, repair the joint similar to the existing joint to maintain a working joint. Form a new joint to the same width as the existing joint. Use compressible joint filler material as inserts to prevent intrusion of the repair material into the joint. Seal the joint according to Subsection 502.07.
(e)Finishing concrete. Finish patches according to Subsection 501.09 to match the plane and texture of the adjacent existing pavement. Cure hydraulic cement concrete according to Subsection 501.10. Cure polymer concrete as recommended by the manufacturer. Restore and compact shoulders with material similar to the existing shoulder.
502.06Full Depth Patching. This work consists of removing existing concrete pavement the full depth and replacing with new concrete according to Section 501.
(a)Concrete removal. Saw cut slabs full depth leaving vertical edges at the limits of the patch. Do not damage adjacent concrete slabs. Remove the concrete by lifting the slab without disturbing the underlying surface. Clean out the area with hand tools. Dispose of the concrete according to Subsection 203.07. Remove and replace adjacent slabs damaged by con crete removal. Repair spalls using partial- depth patching methods according to Subsection 502.05 . Repair saw overcuts of repair areas and nicks to adjacent pavement outside the perimeter of the repair area with non -shrink g rout.
(b)Roadbed preparation. Recondition the base and subgrade material within the patch area according to Subsection 303.06. If required, excavate the underlying material to a maximum depth of 12 inches and replace with crushed aggregate according to Section 302. Prevent adjacent concrete slabs from being undermined.
(c)Joints. Construct joints acco rding to Subsection 501.08. Install dowels, tie bars, or both into existing concrete pavement slabs as shown in the plans. Drill dowel or tie bar holes into the face of the existing concrete at the required diameter, length , and spacing. Provide a drill conforming to Subsection 502.04(d)(2) . Clean and dry the holes before installing the dowels or tie bars. Use an epoxy resin adhesive to permanently anchor the dowel or tie bar into the existing concrete. Place the epoxy resin starting from the back of the hole and use enough quantity to ensure the epoxy material is forced up and around the dowel or tie bar after insertion. Place a thin, donut -shaped grout retention disk around the dowel or tie bar and up against the face of the existing concrete to prevent epoxy resin adhesive material from flowing out of the hole. Seal joints according to Subsection 501.11.
(d)Reinforcing steel. If required , provide welded steel wire f abric reinforcement for crack control. If required, provide and place reinforcing bars according to Section 554. Support reinforcing bars and welded steel wire fabric on chairs or bolsters.
(e)Concrete placement. Construct side forms to overlap the ends of the existing slab. Securely fasten side forms so they do not move when concrete is placed. To accommodate forms for the patch, excavate the adjacent shoulders a maximum width of 12 inches. Place concrete according to Subsection 501.07. Cast each patch in one continuous full -depth operation. After removal of the forms, backfill, compact, and return the excavated shoulder area to its previous condition.
(f)Finishing concrete. Finish patches according to Subsection 502.05(e) .
502.07Resealing Joints and Crack Repair. This work consists of repairing or resealing joints and cracks in existing concrete pavement.
(a)Preparation of joints and cracks. Limit the length of joints and cracks prepared to that which can be resealed within the same shift. Do not damage joints or previously repaired patches. Remove existing sealant from the crack faces to expose new, clean concrete. If the crack widths vary and the c rack faces are raveling and irregular, cut a crack reservoir to a depth of ¾ inch. Thoroughly clean the joint or crack of foreign material by shotblasting, waterblasting, or with a mechanical wire brush. Repeat the process until a new, clean concrete face is exposed. Dry the joint with compressed air. Use sawing if other methods do not properly clean the joint. Limit sawing to exposing clean, new, concrete faces in the joint with a maximum allowable cut of ⅛ inch on each face of the joint.
(b)Backer rod. Insta ll the backer rod to the required depth after the joints and cracks are clean and dry. Do not stretch or twist the backer rod during installation. Limit the length of backer rod installed to that which can be sealed during the same shift.
(c)Sealant application. Seal joints and cracks immediately after placing the backer rod. Apply sealant according to the manufacturer’s recommendations. If the joint or crack becomes contaminated or damp, remove the backer rod, clean and dry the joint or crack, and reinstall a new backer rod before placing the sealant. For a non- self-leveling joint sealant, tool the sealant immediately after application to provide firm contact with the joint faces and to form the required recess below the slab surface.
502.08Pavement Jacking. This work consists of raising and supporting the concrete pavement to the specified grade tolerances by drilling and injecting non-shrink or polyurethane grout.
(a)Drilling holes. Develop a pattern for grout injection holes and submit for approval. Drill vertical holes less than 2 inches in diameter.
(b)Jacking. Establish string lines from the pavement high points to monitor slab movement. Lower an expanding rubber packer or hose into the holes. Provide a positive seal and connection to the discharge ho se on the grout plant. Do not allow the discharge end of the packer or hose to extend below the bottom of the concrete pavement. If jacking continuously- reinforced concrete pavement, allow pumping to raise the pavement to within ⅛ inch of the string line grade. Allow pumping to raise the pavement to within ¼ inch of the transverse and longitudinal grades if jacking jointed pavement and bridge approach slabs. Continuous jacking pressures to 200 pounds per square inch are allowed. Use pressures to 300 pounds per square inch only for short periods of 30 seconds or less. If the pavement is bonded to the subbase, brief pressure rises of 10 seconds or less to 600 pounds per square inch may be allowed. Stop pumping if grout extrudes through cracks, joints, or shoulders. Discontinue pumping if back pressure in the hose exceeds 600 pounds per square inch.
(c)Overjacking. Grind pavement raised above the specified tolerances to grade. Remove and replace the pavement according to Subsection 502.06 if the overjacking is greater than 1 inch.
(d)Cracks. Radial cracks from the grout injection holes will be considered caused by improper injection technique. For slabs with more than 10 feet of new cracks, remove and replace the slab or a portion of slab according to Subsection 502.06. For slabs with less than 10 feet of new cracks, seal cracks according to Subsection 502.07.
(e)Hole patching. After completing the jacking and the hole plugs are removed, fill drill holes flush with the pavement surface with a non -shrink grout or epoxy mortar.
502.09Undersealing and Slab Stabilization. This work consists of pumping a non- shrink or polyurethane grout through holes drilled in the pavement into voids underneath the slabs to stabilize and underseal concrete pavement.
(a)Preliminary testing. Perform testing at night or when there is no evidence of slab lock -up due to thermal expansion. Testing may be allowed to continue if the slabs are not interlocked or under compression. Provide testing equipment conforming to Subsection 502.04(h) . Test designated slab using a static method as follows:
(1)Position one set of gauges with one gauge referenced to the corner of the slab on both sides of the joint near the pavement edge;
(2)Set the gauges to zero with no load on the slab on each side of the joint;
(3)Move the test truck into position and stop with the center of the test axle 12 inches behind the joint and the outside test wheel 12 inches from the pavement edge. Read the back gauge;
(4)Move the test truck across the joint to a similar position 12 inches forward from the joint and stop. Read the forward gauge; and (5) Underseal slabs with a deflection of more than ⅟ 32 inch.
(b)Drilling holes . Develop hole pattern and submit for approval. Drill vertical holes less than 2 inches in diameter to provide a positive seal for the pumping nozzle. For the first undersealing, drill holes to a depth that penetrates unbound base or subgrade. Avoid penetrating the subgrade by more than 3 inches.
(c)Cleaning holes. After the holes are drilled and before pumping the underseal grout, clean the hole with compressed air to remove debris and provide a passage for the grout.
(d)Pumping underseal grout. Pump grout in each hole. Seal the nozzle of the discharge hose in the hole to maintain the grout pressure underneath the slab. Do not allow the nozzle end to extend below the bottom of the concrete. Monitor slab lift according to Subsection 502.08. Limit upward movement of the pavement to ⅛ inch. Continue pumping into a hole until grout flows out other holes, joints, or cracks, or until the slab starts to lift. Stop grouting if there is lift in the slab or the adjacent shoulder. During stabilization operations, limit continuous pumping pressures to 125 pounds per square inch. Allow a short pressure surge of up to 300 pounds per square inch when starting to pump grout into the hole to ensure grout penetrates the void structure . Do not plug other holes while grouting. Grind pavement raised more than the ⅛ inch.
(e)Cracks. If cracks develop, complete the required repairs according to Subsection 502.07.
(f)Hole patching. Patch holes according to Subsection 502.08(e) .
(g)Stability testing. Test for stability 24 hours after designated slabs have been undersealed according to Subsection 502.09(a) . Complete a second underseal operation on slabs that continue to show excess movement. Submit the number, depth, and location of holes for the second undersealing for approval. The CO may direct replacement of slabs that continue to show movement more than that specified after undersealing twice. Remove and r eplace designated slabs according to Subsection 502.06.
502.10Surface Diamond Grinding. This work consists of grinding existing concrete pavement to eliminate joint or crack faults and providing positive lateral drainage. Uniformly transition auxiliary or ramp lane grinding from the mainline edge to provide positive drainage and an acceptable riding surface. Provide a grinding unit conforming to the requirements of Subsection 502.04(e) . Produce a pavement surface that is true to grade, smooth, and consisting of a longitudinal corduroy-type texture. Produce grooves from 0.08 to 0.15 inch wide with a space between the grooves from 0.065 to 0.125 inch wide. Produce peak ridges approximately ⅟ 16 inch higher than the grooves. Adjust blade spacing to achieve the specified texture. Establish a positive and immediate means for removal of grinding residue. Remove solid residue from the pavement surfaces before it is blown by traffic action or wind and dispose of residue according to Subsection 203.07. Do not allow residue to flow into gutters or drainage facilities. Measure the ground pavement surfaces according to Subsection 501.12. Straightedge requirements do not apply across longitudinal joints or outside of ground areas.
502.11Concrete Cleaning. This work consists of cleaning the existing concrete pavement surface with an approved high- pressure washing device. Remove dust, dirt , oil, and other foreign material, including the existing crack sealant material, without causing damage to the surface or exposing coarse aggregate. Vacuum the concrete surface to remove and collect water and debris after the pavement cleaning. Dispose of the water and debris according to Subsection 203.07.
502.12Opening to Traffic. Do not allow traffic on restored pavement until the concrete has a compressive strength of 4000 pounds per square inch if tested according to AASHTO T 22 or until the grout used for jacking or undersealing the pavement has attained 600 pounds per square inch if tested with a 0.25-square inch probe according to AASHTO T 197. As an alternative method of determining the compressive strength of the restored pavement, in situ compressive strength can be measured by developing a strength- maturity relationship of the approved concrete mixture according to AASHTO T 325. Submit the strength -maturity relationship for approval at least 14 days before production. Provide a concrete maturity meter during the test placement and production that meets the following:
(a)Conforms to AASHTO T 325;
(b)Rugged, waterproof, and can withstand the construction environment;
(c)Able to operate without an external power source for a t least 14 days;
(d)Able to collect and store temperature and maturity data for at least 14 days; and
(e)Able to determine equivalent maturity hours according to the Arrhenius function. Do not allow traffic on sealed joints while the sealant is tacky and traffic debris embeds into the sealant.
502.13Acceptance. See Table 502-1 for sampling, testing, and acceptance requirements. Material for concrete pavement restoration will be evaluated under Subsections 106.02 and 106.03. The concrete mixture’s slump, air content, density, temperature, and compressive strength wi ll be evaluated under Subsections 106.02 and 106.04. Concrete pavement restoration construction will be evaluated under Subsections 106.02 and 106.04. Crushed aggregate will be evaluated under Section 302. Hydraulic cement concrete will be evaluated under Section 501. Polymer concrete will be eval uated under Section 572. Reinforcing steel will be evaluated under Section 554.
Measurement
502.14Measure the Section 502 pay items listed in the bid schedule according to Subsection 109.02 and the following as applicable: When measuring grout for pavement jacking and undersealing by the cubic foot, measure by metering.
Payment
502.15The accepted quantities will be paid at the contract price per unit of measurement for the Section 502 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 . Table 502-1 Sampling, Testing, and Acceptance Requirements
Material or
Product
(Subsection) Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Source
Aggregate
(703.01 & 703.02) Measured & tested for conformance (106.04 & 105) Quality − AASHTO M 80, M 6, & M 43 1 per material type Source of material Yes 14 days before paving −
Mix Design
Concrete
composition (501.03 ) Measured & tested for conformance (106.04 & 105) All − Subsection
501.031 per mix design Source of material Yes 14 days before paving −
Production
Concrete Measured &
tested for conformance (106.04 ) Density − AASHTO T 121 1 per load(2) Point of discharge(3) No Upon completing tests − Air content − AASHTO T 152 " " " " − Slump − AASHTO T 119 " " " " − Temperature − Field measured " " " " − Table 502-1 (continued) Sampling, Testing, and Acceptance Requirements
Material or
Product
(Subsection) Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Production (continued)
Concrete Measured &
tested for conformance (106.04 ) Compressive strength(1),(4) − AASHTO T 23 & T 22 1 set per 200 yd2 but not less than 1 set per day Point of discharge(3) (4) " Deliver verification cylinders to the CO or designated location within 28 days
Aggregate
(coarse & fine) Process control (153.03 ) Gradation − AASHTO T 27 & T 11 1 per day minimum Bin discharge, conveyor belt, or stockpile No Before batching − Moisture − AASHTO T 255 " " " " − Concrete " Surface tolerance − Straightedge measurements
Subsection
501.09Subsection
501.09Concrete surface, after floating " While concrete is still workable − Table 502-1 (continued) Sampling, Testing, and Acceptance Requirements
Material or
Product
(Subsection) Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Finished Product
Concrete
pavement Measured & tested for conformance (106.04 ) Surface tolerance − Straightedge measurements
Subsection
501.12Successively, after concrete has cured Finished pavement surface No 24 hours −
(1)A single compressive strength test result is the average result from two 6 - by 12- inch or three 4 - by 8- inch cylinders cast from the same load and tested at 28 days.
(2)This frequency may be reduced by the CO if produced material proves to be consistent.
(3)Sample according to AASHTO R 60.
(4)Make at least four 6 - by 12 -inch or six 4- by 8-inch compressive strength test cylinders and carefully transport the cylinders to the project curing facility. Two or three cylinders will be used for 28 -day compressive strength tests. The remaining cylinders will be used by the CO for verification testing or other designated purposes. DIVISION 550