431—EPOXY BRIDGE DECK OVERLAYS

431.01 Description

This work shall consist of preparing the deck surface and furnishing and applying epoxy as an overlay over concrete bridge decks in accordance with this Specification, and within the specified tolerances for the lines, grades and details shown on the plans.

431.02 Materials

431.03 Procedures

Personnel shall be thoroughly trained in the safe handling of materials in accordance with the manufac - turer’ s recommendations and the MSDS included with the materials. Epoxy shall be stored in accordance with Section 243. MSDS and other information pertaining to safe practices for storage, handling and disposal of the materials, and to their health hazards shall be obtained from the manufacturer and posted at storage areas. A copy of such information shall be provided to the Engineer. Prior to placing the first course, the entire deck surface shall be cleaned by shot-blasting and other means. The Contractor shall determine the bridge deck cleaning method by preparing and testing trial patches in accor - dance with VTM-92 to obtain the size of shot, flow of shot, forward speed of shot-blast machine, and number of passes necessary to provide a tensile rupture strength of the bond interface greater than or equal to 250 psi or a failure area, at a depth of 1/4 inch or more into the base concrete, greater than 50 percent of the test area. A test result shall be the average of three tests on a test patch of at least 1.5 feet by 3 feet consisting of two courses. One passing test result must be obtained for each span or 300 square yards, whichever is the smaller area. Test patches shall be placed in wheel paths, the area between wheel paths, or in other areas that represent a worst surface condition as determined by the Engineer. Test patches shall be installed with the same materials, equipment, personnel, timing, sequence of operations, and curing period prior to opening to traffic that will be used for the installation of the overlay. The cleaning method, materials, and installation procedure will be approved if one passing test result is obtained from each test area. If the cleaning method, materials, and installation procedure are not acceptable, the Contractor must remove the failed test patches and make the necessary adjustments, and then retest all test areas until test results are satisfactory at no additional cost to the Department. The cleaning method shall remove asphaltic material, oils, dirt, rubber, curing compounds, paint car - bonation, laitance, weak surface mortar and other potentially detrimental materials that may interfere with the bonding or curing of the overlay. Acceptable cleaning is usually recognized by a significant change in the color of the concrete and mortar, and the beginning exposure of coarse aggregate particles. Mortar that is sound and soundly bonded to the coarse aggregate must have open pores due to cleaning to be considered adequate for bond. Areas of asphalt larger than one inch in diameter, or smaller areas spaced less than six inches apart, shall be removed. Traffic paint lines shall be considered clean when the concrete has exposed aggregate showing through the paint stripe. Vacuum cleaning equipment shall be used to remove all dust and other loose material. Brooms shall not be used and will not be permitted.431.01 641If the Engineer determines that an approved cleaning method has changed prior to the completion of the job, the Contractor shall return to the approved cleaning methods and reclean the suspect areas or verify through tests that the altered method is acceptable at no additional cost to the Department. Epoxy overlay shall not be placed on hydraulic cement concrete that is less than 28 days old. Patching and cleaning operations shall be inspected and approved prior to placing each layer of the overlay. Any contamination of the deck or intermediate courses after initial cleaning shall be removed. Both courses shall be applied within 24 hours following the final cleaning and prior to opening the area to traffic. There shall be no visible moisture present on the surface of the concrete at the time of application of the epoxy overlay. Oil-free compressed air may be used to dry the deck surface. Mechanical application equipment shall consist of no less than an epoxy distribution system, fine aggre - gate spreader, application squeegee, vacuum trucks, and a lighting source if work will be performed at night. The distribution system or distributor shall accurately blend the epoxy resin and hardening agent in the proportions recommended by the manufacturer and shall uniformly and accurately apply the epoxy materials to the bridge deck at the specified application rate in a manner that covers 100 percent of the work area. The fine aggregate spreader shall uniformly and accurately apply the dry silica sand or basalt to cover 100 percent of the epoxy material. The vacuum truck shall be self-propelled. Hand application equipment shall consist of calibrated containers, a paddle-type mixer, squeegees, rollers and brooms that are suitable for mixing the epoxy and applying the epoxy and aggregate in accordance with Section 243. Handling and mixing of the epoxy resin and hardening agent shall be performed in a safe manner to achieve the desired results in accordance with Section 243 and the manufacturer’ s instructions as approved or directed by the Engineer. Epoxy overlay materials shall not be placed when weather or surface conditions inhibit proper handling, placing, spreading, and curing within the project limitations of operations. The epoxy overlay shall be applied in 2 separate courses in accordance with the following rate of application, and the total of the 2 applications shall not be less than 7.5 gals. per 100 square feet. Application Rates Course Epoxy gal./100 sq.ft. Aggregate lbs./sq.yd.* 1 No less than 2.5 10+ 2 No less than 5.0 14+ * Application of aggregate shall be of sufficient quantity to completely cover the epoxy. After the epoxy mixture (resin+hardening agent) has been prepared for the epoxy overlay, it shall be immediately and uniformly applied to the surface of the bridge deck with a squeegee or paint roller. The temperature of the bridge deck surface and all epoxy and aggregate components shall be 60 degrees F or above at the time of application. Epoxy shall not be applied if the air temperature is expected to drop below 55 degrees F within 8 hours after application, or if the gel time is less than 10 minutes. The dry aggregate shall be applied in such a manner as to cover the freshly placed epoxy mixture completely within 5 minutes. First course applications that do not receive enough sand prior to gel, as determined by the Engineer, shall be removed and replaced. Insufficiently sanded second courses may be left in place, but require additional epoxy-sand applications to deficient areas before opening to traffic. Each course of epoxy overlay shall be cured until vacuuming or brooming can be performed without tearing or damaging 431.03 642the surface. Traffic or equipment shall not be permitted on the overlay surface during the curing period. After the curing period for Course 1, all loose aggregate shall be removed by vacuuming or brooming and the next overlay course applied. The minimum curing periods shall be as follows: Course Average temperature of deck, epoxy and aggregate components in degrees F 60 to 64 65 to 69 70 to 74 75 to 79 80 to 84 85+ 1 4 hrs. 3 hrs. 2.5 hrs. 2 hrs. 1.5 hrs. 1 hr. 2* 6.5 hrs. 5 hrs. 4 hrs. 3 hrs. 3 hrs. 3 hrs. * Course 2 shall be cured for 8 hours if the air temperature drops below 60 degrees F during the curing period. The Contractor shall plan and prosecute the work to provide the minimum curing periods as specified herein, or other longer minimum curing periods as prescribed by the manufacturer prior to opening to public or construction traffic, unless otherwise permitted. Course 1 applications shall not be opened to traffic. Unless otherwise specified, the epoxy overlay courses shall be applied over the expansion joints of the bridge deck. The expansions joints shall be provided with a bond breaker. Within 12 hours of application and prior to opening to traffic, the overlay shall be removed over each joint by removal of the bond breakers, or by scoring the overlay prior to gelling or by saw-cutting after curing. Unless otherwise specified, the epoxy overlay courses shall be applied to the area of the face of the curb or parapet for a distance of 6 inches from the face of the deck. Vertical and inclined surfaces on the face of the curb shall be cleaned by abrasive blast cleaning but do not require broadcast aggregate. If the Contractor’ s operation damages or mars the epoxy overlay, the Contractor shall remove the damaged areas by saw-cutting the perimeter of the damaged areas in rectangular sections to the top of the concrete deck surface and replacing the various courses in accordance with this Specification at no additional cost to the Department. The method for removing the damaged sections of epoxy overlay shall be developed by the Contractor, and submitted to the Engineer for review. The Contractor shall maintain and provide the Engineer with records for each batch provided including, but not limited to: • Batch numbers and volumes • Location of batches as placed on deck, referenced by stations • Batch time • Gel time (50 ml sample) • Temperature of the air, deck surface, epoxy components, including aggregates • Loose aggregate removal time • Time open t o traffic

431.04 Measurement and Payment

Epoxy overlay will be measured in square yards and will be paid for at the contract unit price per square yard. This price shall be include preparing deck and testing, furnishing and applying the overlay courses (epoxy and aggregate)removing and disposing of loose/excess aggregate, and saw-cutting joints.431.03 643Payment will be made under: ——————————————————— Pay Item Pay Unit——————————————————— Epoxy overlay Square yard———————————————————431.04 645DIVISION V INCIDENTAL CONSTRUCTION 647501.03 SECTION 501—UNDERDRAINS, CROSSDRAINS, AND EDGEDRAINS

501.01 Description

This work shall consist of constructing underdrains, crossdrains, edgedrains, and prefabricated geo - composite pavement edgedrains (PGPE), including outlet pipe, (collectively, “underdrains”) using pipe, aggregate, and geosynthetics, in accordance with these specifications, the VDOT Road and Bridge Standards, and in conformity to the lines and grades shown on the plans or as designated by the Engineer.

501.02 Materials

501.03 Procedures