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BRIDGE DECK THIN POLYMER OVERLAY SYSTEM SPV

By Erica Henry,2014-11-28 13:03
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BRIDGE DECK THIN POLYMER OVERLAY SYSTEM SPV

EPOXY OVERLAY, ITEM SPV.0180.XX.

A Description

    This special provision describes furnishing and applying two layers of a two-component polymer overlay system to the bridge decks shown on the plans. The total thickness of the overlay system shall be 3/8”.

B Materials

    B.1 General

    Furnish materials specifically designed for use over concrete bridge decks. Pre-qualified polymer liquid binders are as follows:

Product Trade Name Manufacturer or Supplier Telephone

    Mark-163 Flexogrid PolyCarb, Inc. (866) 765-9227

    Sikadur 22 Lo-mod Sika Corporation (248) 569-5665

    E-Bond 526 Lo-Mod E-Bond Epoxies, Inc. (954) 566-6555

    Propoxy DOT Type III Unitex (816) 231-7700

    Sure Level Epoxy (J-57) Dayton Superior (888) 977-9600

    ICO Flexi-Coat International Coatings, Inc. (800) 624-8919

    Flexolith Euclid Chemical Co. (800) 321-7628

B.2 Polymer Resin

    The polymer resin base and hardener shall be composed of two-component, 100% solids, 100% reactive, thermosetting compound with the following properties:

Property Requirements Test Method

    AGel Time ASTM C881 15 - 45 minutes @ 75 F

    ASTM D2393, Brookfield AViscosity 7 - 70 poises RVT, Spindle No. 3, 20 rpm BShore D Hardness 60-75 ASTM D2240 BAbsorption 1% maximum at 24 hr ASTM D570 BTensile Elongation 30% - 70% @ 7 days ASTM D638 BTensile Strength >2000 psi @ 7 days ASTM D638 BFlexural Strength >4500 psi @ 7 days ASTM D790 BChloride Permeability <100 coulombs @ 28 days AASHTO T277 A Uncured, mixed epoxy binder B Cured, mixed epoxy binder

B.3 Aggregates

    Furnish natural or synthetic aggregates that have a proven record of performance in applications of this type. Furnish aggregates that are non-polishing, clean, free of surface moisture, fractured or angular in shape; free from silt, clay, asphalt, or other organic materials; and meet the following properties and gradation requirements:

Aggregate Properties:

    Property Requirement Test Method

    Moisture Content ASTM C566 ;0.2%

    Hardness Mohs Scale 6.5

    100% with at least 1

    fractured face &

    80% with at least 2 Fractured Faces ASTM 5821 fractured faces of

    material retained on

    No.16

Gradation:

    Sieve Size % Passing by Weight

    No. 4 100

    No. 8 30 75

    No. 16 0 5

    No. 30 0 1

B.4 Required Properties of Overlay System

    The required properties of the overlay system are listed in the table below:

    ARequirement Property Test Method

    Minimum Compressive 1,000 psi @ 8 hrs ASTM C 579 Method B, BStrength at 8 Hrs. (psi) 5,000 psi @ 24 hrs Modified

    Thermal Compatibility No Delaminations ASTM C 884

    Minimum Pull-off Strength 250 psi @ 24 hrs ACI 503R, Appendix A

    A Based on samples cured or aged and tested at 75?F B Plastic inserts that will provide 2-inch by 2-inch cubes shall be placed in the

    oversized brass molds.

B.5 Approval of Bridge Deck Polymer Overlay System

    A minimum of 20 working days prior to application, submit product data sheets and specifications from the manufacturer, and a certified test report to the engineer for approval. The engineer may request samples of the polymer and/or aggregate, prior to application, for the purpose of acceptance testing by the department.

    For materials not pre-qualified, in addition to the above submittals, submit product history/reference projects and a certified test report from an independent testing laboratory showing compliance with the requirements of the specification.

    The product history/reference projects consist of a minimum of 5 bridge/roadway locations where the proposed overlay system has been applied in Wisconsin or in locations with a similar climate - include contact names for the facility owner, current phone number or e-mail address, and a brief description of the project.

    Product data sheets and specifications from the manufacture consists of literature from the manufacturer showing general instructions, application recommendations/methods, product properties, general instructions, or any other applicable information.

C Construction

    C.1 General

    Conduct a pre-installation conference with the manufacturer's representative prior to construction to establish procedures for maintaining optimum working conditions and coordination of work. Furnish the engineer a copy of the recommended procedures and apply the overlay system according to the manufacturer’s instructions. The

    manufacturer's representative familiar with the overlay system installation procedures shall be present at all times during surface preparation and overlay placement to provide quality assurance that the work is being performed properly.

    Store resin materials in their original containers in a dry area. Store and handle materials according to the manufacturer’s recommendations. Store all aggregates in a dry

    environment and protect aggregates from contaminants on the job site.

C.2 Deck Preparation

    C.2.1. Deck Repair

    Remove all asphaltic patches and unsound or disintegrated areas of the concrete decks as the plans show, or as the engineer directs. Work performed to repair the concrete deck will be paid for under the item for deck patching. Insure that products used for deck patching are compatible with the epoxy overlay system.

    NOTE: Some epoxy systems require concrete patch material to be in place a minimum of 28-days before overlaying - contact epoxy manufacturer before completing deck patching/repair.

C.2.2 Surface Preparation

    Determine an acceptable shotblasting machine operation (size of shot, flow of shot, forward speed, and/or number of passes) that provides a surface a profile meeting CSP 5 according to the International Concrete Repair Institute Technical Guideline No. 03732. If the engineer requires additional verification of the surface preparation, test the tensile bond strength according to ACI 503R, Appendix A of the ACI Manual of Concrete

    Practice. The surface preparation will be considered acceptable if the tensile bond strength is greater than or equal to 250 psi or the failure area at a depth of ? inches or more is greater than 50% of the test area. Continue adjustment of the shotblasting machine and necessary testing until the surface is acceptable to the engineer or a passing test result is obtained.

    Prepare the entire deck using the final accepted adjustments to the shotblasting machine as determined above. Thoroughly blast clean with hand-held equipment any areas inaccessible by the shotblasting equipment. Do not perform surface preparation more than 24 hours prior to the application of the overlay system.

    Just prior to overlay placement, clean all dust, debris, and concrete fines from the deck surface including vertical faces of curbs and barrier walls up to a height of 1 inch above the overlay with compressed air. When using compressed air, the air stream must be free of oil. Any grease, oil, or other foreign matter that rests on or has absorbed into the concrete shall be removed completely.

    Cover the bridge deck drains and bridge expansion joints to prevent materials from adhering and entering.

    Create a transitional area approaching transverse expansion joints and ends of the deck using the shotblasting machine or other approved method. Remove 5/16” to 3/8” of

    concrete adjacent to the joint or end of deck and taper a distance of 3 feet. The engineer may consider alternate surface preparation methods per the overlay system manufacture’s recommendations. The engineer will approve the final surface profile

    and deck cleanliness prior to the contractor placing the epoxy overlay.

C.3 Application of the Overlay

    Perform the handling and mixing of the epoxy resin and hardening agent in a safe manner to achieve the desired results according to the manufacturer’s instructions. Do not apply

    the overlay system if any of the following exists: oa. Ambient air temperature is below 50F; ob. Deck temperature is below 50F;

    c. Moisture content in the deck exceeds 4.5% when measured by an electronic

    moisture meter or shows visible moisture after 2 hours when measured in

    accordance with ASTM D4263;

    d. Rain is forecasted during the minimum curing periods listed under C.5 ; oe. Materials component temperatures below 50F;

    f. Concrete age is less than 28 days unless approved by the engineer.

    After the deck has been shotblasted or during the overlay curing period, only necessary surface preparation and overlay application equipment will be allowed on the deck. Begin overlay placement as soon as possible after surface preparation operations.

    The polymer overlay shall consist of a two-course application of epoxy and aggregate. Each of the two courses shall consist of a layer of epoxy covered with a layer of aggregate in sufficient quantity to completely cover the epoxy. Apply the epoxy and aggregate according to the manufacturer’s requirements. Apply the overlay using

    equipment designed for this purpose. The application machine shall feature positive displacement volumetric metering and be capable of storing and mixing the polymer resins at the proper mix ratio. Disperse the aggregate using a standard chip spreader or equivalent machine that can provide a uniform, consistent coverage of aggregate. First

    course applications that do not receive enough aggregate before the epoxy gels shall be removed and replaced. A second course applied with insufficient aggregate may be left in place, but will require additional applications before opening to traffic.

    After completion of each course, cure the overlay according to the manufacturer’s instructions. Follow the minimum cure times listed under C.5 or as prescribed by the manufacturer. Remove the excess aggregate from the surface treatment by sweeping, blowing, or vacuuming without tearing or damaging the surface; the material may be re-used if approved by the engineer and manufacturer. Apply all courses of the overlay system before opening the area to traffic. Do not allow traffic on the treated area until directed by the engineer.

    After the first layer of coating has cured to the point where the aggregate cannot be pulled out, apply the second layer. Prior to applying the second layer, broom and blow off the first layer with compressed air to remove all loose excess aggregate.

    Prior to opening to traffic, clean expansion joints and joint seals of all debris and polymer. If required by the engineer, a minimum of 3 days following opening to traffic, remove loosened aggregates from the deck, expansion joints, and approach pavement.

4 Application Rates C.

    Apply the epoxy overlay in two separate courses in accordance with the manufacturer’s

    instructions, but not less than the following rate of application.

    ABMinimum Epoxy Rate Aggregate Course (GAL/100 SF) (LBS/SY)

    1 2.5 10+

    2 5.0 14+ A The minimum total applications rate is 7.5 GAL/100 SF. B Application of aggregate shall be of sufficient quantity to completely cover the epoxy.

C.5 Minimum Curing Periods

    As a minimum, cure the coating as follows:

     Average temperature of deck, epoxy and aggregate components in ?F

    Course 60-64 65-69 70-74 75-79 80-84 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.

    * Cure course 2 for 8 hours if the air temperature drops below 60 F during the curing

    period.

D Measurement

    The department will measure Epoxy Overlay in area by square yards of completed and accepted work.

E Payment

    The department will pay for measured quantities at the contract unit price under the following bid item:

ITEM NUMBER DESCRIPTION UNIT

    SPV.0180.XX Epoxy Overlay SY

    Payment is full compensation for preparing the surface; for tensile bond testing; for providing the overlay; for cleanup; for sweeping/vacuuming and disposing of excess materials; and for labor, equipment, tools, and incidentals necessary to complete the work. Concrete Deck Repair will be paid for separately.

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