729 - MULTI-LAYER POLYMER CONCRETE OVERLAY .
TABLE 729-3: EPOXY CURE TIMES for MULTI-LAYER POLYMER CONCRETE OVERLAYS Course Average Temperature of Overlay Components, °F 55-59 60-64 65-69 70-74 75-79 80-85 85+ Minimum Cure Time (hours) 1 5 4 3 2.5 2 1.5 1 2 6.5 6.5 5 4 3 3 3
Cure the second course for 8 hours if the air temperature falls below 55 F during the curing period before opening to traffic.
Accelerators and inhibitors may be requ ired to achieve proper set times. Pr oportion all materials as recommended by the material supplier.
specification or as specified by th e material manufacturer/supplier.
day’s work whichever is smaller. Submit a sequence plan to the Engineer. Test patches shall be full depth, placed by the normal construction sequence. Test patches should be representative of the work being performed.
Type 1 – Failure in the concrete at a depth greater than or equal to ¼ inch over more than 50% of the test area for 3 out of 4 tests in the test patch. Type 2 – Failure in the concrete at a depth less than ¼ inch over more than 50% of the test area for 3 out of 4 tests in the test patch. Minimum Tensile Rupture Strength of 250 psi from an average of 3 out of 4 tests on a test patch regardless of depth of failure.
less than 250 psi, or the failure in the concrete is less than 50% of the test area, ad ditional surface preparation is necessary.
overlay bond. No additional su rface preparation is required.
tapping or chaining and areas where the overlay was damaged by the Contractor’s operation. Saw cut the unbonded or damaged areas to the top of the deck surface, remove the overlay with small air t ools (15-pound class maximum) or shot blasting. Aggressively sandblast or shot blast the concrete bridge deck surface at the unbonded area to remove contaminants. Replace the overlay according to standard placement proc edures at no additional compensation.
placement.
expected to drop below 40 F during installation.
Do not place the overlay if gel time is less than 10 minutes. The overlay may be placed outside the specified temperature ranges with the approval of the Engineer and the material manufacturer/supplier. Discuss changes to temperature limitations at the preconstruction conference. 729 - MULTI-LAYER POLYMER CONCRETE OVERLAY
700-113Submit changes, including a written statement from the polymer manufacturer/supplier recommending the changes,
to the Engineer for approval.
729.4MEASUREMENT AND PAYMENT
The Engineer will measure multi-layer polymer concre te overlay by the square yard. The Engineer will measure the bridge roadway width and the bridge length from end of wearing surface to end of wearing surface. Payment for "Multi-Layer Polymer Concrete Overlay" at the contract unit price is full compensation for the specified work. 730 - EPOXY RESIN CRACK REPAIR
700-114SECTION 730
EPOXY RESIN CRACK REPAIR
730.1DESCRIPTION
Repair cracks in the concrete by epoxy injection at th e locations shown in the Contract Documents, or as designated by the Engineer. B I D I T E M U N I T S Epoxy Resin Crack Repair Linear Foot
730.2MATERIALS
Provide a Type IV, Grade 1, Class B or C epoxy ma terial for injection purp oses that complies with For sealing surface cracks, provide either: Silicone Rubber Surface Crack Sealant (c lear or gray) that complies with SECTION 1724 . Type IV, Grade 3, epoxy ma terial that complies with SECTION 1705 .
730.3CONSTRUCTION REQUIREMENTS
work starts on the project. Arrange to have a representative of the Bureau of Research present when the work begins. The KDOT representative will remain on the project until both the Contractor and Inspectors have an understanding of the proper procedures for this work. Provide a log and record the followi ng data as injection proceeds: The date the injection ports are set; The date the injection is performed; The length of the crack injected; The amount of epoxy used; The temperature of the concrete in which the injection is performed; and The air temperatures when injection is performed.
The Project Engineer must approve the injection log and verify the correctness of the recorded data. Upon completion of the project, provide the Project Engineer with th e recorded data. The Project Engineer will forward this information to the Bureau of Structures and Geotechnical Services. Make a representative of the material manufacturer available at the request of the Engineer. Injected epoxy resin must be allowed to set a minimum of 4 hours before allowing traffic on the structure. The materials, construction procedures, and the completed project will be inspected and approved by the Engineer.
cracks, clean the surface to whic h the sealant will be applied. Do not apply the sealant to wet surfaces. Apply the sealant with a minimum thickness of ⅛ inch, and a width of ¾ inch on both sides and ends of the crack. If silicone rubber sealant is used, allow the sealant to cure a minimum of 24 hours. If an epoxy sealant is used, follow the epoxy manufacturer’s recommendations for minimum cure time requirements based on substrate and ambient temperatures.
used, vacuum drilling of the port holes is required. Place drilled injection ports at a depth recommended by the injection equipment manufacturer. 730 - EPOXY RESIN CRACK REPAIR
700-115Space the epoxy injection ports as recommended by the material supplier and/ or the epoxy injection
equipment manufacturer. Allow adhesive used to attach injection ports to cure for 24 hours before injecting the epoxy resin. Begin injecting at the lowest part of the concrete an d work upward as the cracks are filled. This will be evidenced by the presence of epoxy in th e next port above. On horizontal cracks proceed with injection from one end of the crack and work toward the other. Check for leaks in the surface sealed cracks during the epoxy injection operations. If leaks are found, repair the sealant with hot glue and tongue depressors or other methods approved by the Engineer. On cracks of ⅛ inch or wider, limit the back pressure to a maximum of 30 psi. On all other cracks, maintain the back pressure between 80 and 100 psi. After the injection is complete clean all surfaces of sealer and epoxy materials.
730.4MEASUREMENT AND PAYMENT
The Engineer will measure epoxy resin crack repair by the linear foot. Payment for "Epoxy Resin Crack Repair" at the cont ract unit price is full compensation for the specified work.