STATE OF OHIO DEPARTMENT OF TRANSPORTATION SUPPLEMENTAL SPECIFICATION 858 THIN POLYMER (EPOXY) OVERLAYS FOR STRUCTURAL SLABS.

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1 STATE OF OHIO DEPARTMENT OF TRANSPORTATION SUPPLEMENTAL SPECIFICATION 858 THIN POLYMER (EPOXY) OVERLAYS FOR STRUCTURAL SLABS April 20, Description Bridge Decks Repairs Thin Polymer (Epoxy) Overlay Delivery of Materials Storage of Materials Technical Support Equipment Test Patch Protection of the Public Limitations on Placing Operation Transitional Area Preparation of Existing Deck Epoxy-Based Resin Application Aggregate Application Curing Surface Preparation between Overlay Layers Sampling and Testing Defective Work Method of Measurement Basis of Payment Description. The work consists of furnishing the necessary labor, materials and equipment to overlay concrete bridge decks, backwalls, approach slabs and barriers/curbs 3 inches above the deck surface, in accordance with these specifications, Contract Documents, and as directed by the Engineer. Included in this work; scarification of the existing concrete surface; abrasive blast cleaning; furnishing, placing, finishing, texturing and curing of a two course thin polymer (epoxy) overlay wearing system and all other operations necessary to complete this work Bridge Decks Repairs. Perform deck patching as required in the Contract Documents or as directed by the Engineer under item 519, Patching Concrete Bridge Decks. Perform all repairs prior to any surface preparation operations for the thin polymer overlay. Patching material will be a quick setting cementitious mortar meeting the requirements of , any patching material containing Magnesium Phosphate Based Materials will not be allowed (including any on the QPL list). 1

2 Allow patches to cure a minimum of 28 days prior to concrete removal, surface preparation and overlay placement. Traffic will be allowed to use the bridge during the curing period of the patches. Contractor may submit patching material with shorter cure durations with Polymer Epoxy Overlay manufacturer s approval and with the Engineers approval. Depressions in the deck surface less than 2 inches may be filled with an epoxy mortar mix made from Polymer Epoxy Overlay material per the manufactures recommendation. Perform crack sealing for crack with a width greater than 13 mills per CMS , Sealing Cracks by Epoxy Injection. Open the bridge to traffic during all non-working hours, therefore, schedule and perform patching accordingly. Exceptions to this would be other construction activities on the approach roadway which prevent opening the road to traffic Thin Polymer (Epoxy) Overlay. The thin polymer overlay consist of epoxy resin and aggregates. The Engineer will accept materials, as specified. Provide Certificates of Compliance stating materials fully comply with the requirements. Provide proof of compliance with the following information 30 days prior to placement of overlay; A. Project Name B. Name of Prime Contractor and Subcontractor(s) involved with work under this special provision. C. List of Materials and quantities. (including any materials required under section , Bridge Deck Repairs) D. Material Certifications from System Provider. Supply the epoxy two-component, (base and hardener) from the same manufacture that are compatible with one another and meet the material requirements listed in this specification. Provide independent lab test results, conducted no more than one year prior to submittal. E. Means of identifying the consignments, such as labels and markings. F. Dates of shipment and storage requirements. G. Aggregate approval letter by the epoxy-based resin Manufacturer. H. Submit an application process to include working times and weather limitation. I. Test patch location, time, and procedure. The Engineer has the discretion to sample and test materials accepted on the basis of Certificates of Compliance at any time. The Department will reject materials and assemblies, whether in place or not, if found not to be in compliance with contract documents. 1. Epoxy Resin: Provide a two-component, (base and hardener) consisting of volumetric mixing ratios such as one to one or two to one. Provide the two-component contain 100% solids, thermosetting, moisture insensitive, flexible, high elongation epoxy resin meeting the following physical requirements at 75 +/- 2ᵒF ( 24 +/- 1ᵒC) when the base and hardener are combined; 2

3 Gel Time Property Requirement Test Method Tensile Strength (neat), 7- day Tensile Elongation (neat), 7-day minutes 2,500-5,000 psi ( MPa) ASTM C 881 (para modified, 70 ml sample) ASTM D % ASTM D 638 Absorption (neat), 24-hour 1%, Maximum ASTM D 570 Compressive Strength (mixed with aggregate), 3 hrs. Compressive Strength (mixed with aggregate), 24 hrs. Permeability to chloride ion, 28-days Thermal Compatibility (Mixed with aggregate) Infrared spectrum 1,000 psi, minimum (6.9 MPa) 5,000 psi, minimum (34.4MPa) 100 coulombs, Maximum No delamination of overlay or cracks in the concrete Established for each for each component for each Manufacturer ASTM C 579, Method B ASTM C 579, Method B AASHTO T 277 ASTM C 884 AASHTO T 237 (para. 4 & 5) 2. Fine Aggregate: Provide aggregate consisting of flint, granite, basalt, or calcined bauxite. Silica sand is not permissible. Furnish aggregate free of dirt, clay, asphalt, and other foreign or organic materials. Furnish aggregate non-friable, non-polishing, and conforming to the following requirements: 3

4 Aggregate Properties: Property Requirement Test Method Moisture Content 0.2% by weight ASTM C566 Hardness Mohs Scale Fractured Faces 100% with at least 1 fractured face ASTM D5821 Absorption 1% ASTM C128 Micro-Deval, max. 10% AASHTO TP58 Aggregate Gradation: Sieve Size Percent Passing #4 100 # # # Delivery of Materials. Deliver all materials in their original containers bearing the manufacturer s label, specifying date of manufacturing, batch number, trade name, and quantity. Each shipment of two-component resin (base and hardener) will be accompanied by a Material Safety Data Sheet (MSDS) Storage of Materials. Stock and store all material necessary to perform the entire overlay application prior to any field preparation. Store the material to prevent damage by the elements and to ensure the preservation of their quality and fitness for the work. Keep the storage space clean and dry, and provide a high-low thermometer. Do not allow the temperatures of the storage space fall below 60 ᵒF (16 ᵒC) or exceed 100 ᵒF (38 ᵒC). Take extreme precaution to avoid material contact with flame and water Technical Support. Provide a Manufacturer Technical Representative to be present during the test patch application per section , present for 4 hours of surface preparation, and 4 hours of overlay application. The Manufacturer Technical Representative will be made available throughout the duration of the overlay application. Manufacturer Technical Representative will provide recommendations to the Engineer on approval or disapproval of deck surface preparation, equipment, mixing of components, type and method of application, and finish. 4

5 Equipment. 1. Surface Preparation Equipment. Use automatic shot blasting units. Provide shot blasting equipment capable of removing partially loosened chips of concrete, cleaning the bridge deck surface, roughening the bridge deck surface, and removing rust and/or corrosion from steel expansion joint assemblies. In those areas not accessible to this machinery, the surface may, with Engineers approval, be cleaned with other abrasive cleaning equipment. Do not use scarifiers, milling machines, or sandblasting in lieu of shot blasting, unless otherwise approved by the Engineer the pavement surfaces. Automatic shot blasting units will be self-propelled and include vacuum to recover spent abrasive. Use steel shot abrasive. Use magnetic rollers to remove any spent shot remaining on the deck after vacuuming. In those areas not accessible to this machinery, the surface may, with Engineers approval, be cleaned with other abrasive cleaning equipment. 2. Epoxy Resin Application Equipment. Provide mechanical metering, mixing, and distribution equipment that accurately meters and blends the base and hardening components, and delivers the blended epoxy-based resin at the rate to the bridge deck in order to cover 100% of the work area. Furnish application equipment capable and heat the material to above 75 degrees from holding tanks to point of dispensing material. Devices that simultaneously dispense and spread liquid over the width of the application area will not be permitted. 3. Aggregate Application Equipment. Provide a fine aggregate spreader that uniformly applies the aggregate at the specified rate in order to cover 100% of the work area. 4. Hand Application Equipment. The use of hand applicator to aid in the evenly spreading of Epoxy Resin is permitted. Hand applicators may be notched squeegees or rollers for use with epoxy. Hand application for broad casting of aggregates may be allowed for small or irregular areas where the Engineer determines the use of mechanical equipment is not practical Test Patch. Prior to constructing the overlay, conduct one test patch, 100 square feet (minimum). The test patch consists of surface preparation, the first course of epoxy, aggregate, and surface preparation for the second course (do not apply second course) per this specification. Submitted test patch location and plan to the engineer for approval. Document in the plan that the cleaning procedure, materials, installation procedure, and curing period will provide the desired overly. Install the test patch with the same materials, equipment, personnel, timing, sequence of operations, and curing period that will be used for the installation of the overlay. The cure period is equal to the time to open to traffic Include in the test plan how the contractor plans to protect areas not to be covered with the overlay (such as curbs, sidewalks, expansion joints, railing, or drainage items) The cleaning practice, materials and installation procedure will be approved if passing test results are obtained. Test patch locations may be used on the bridge at the contractors own risk. 5

6 Perform a minimum of 2 pull off tests consisting, of three pull off samples per ASTM 1583, on the test patch after placement of trial application. Ensure a minimum bond strength of 250 psi is achieved, as determined by ASTM 1583, to ensure that the overlay adheres to the prepared surface. Surface must be capable of tensile bond strength greater than or equal to 250 psi or a failure area, at a depth of 1/8 or more into the base concrete. Tests performed under 12 hours of completion of the test patch require the surface temperature of the deck to be below 85ᵒF (29ᵒC). If the cleaning practice, materials and installation procedure are not acceptable, the Contractor will be responsible to remove failed test patches and make the necessary adjustments, repeat surface preparation per this specification, and re-test all areas at no additional cost to the Department until satisfactory test results are obtained. An overlay test patch will be rejected upon pull off test failure rate greater than or equal to 50 percent. Construct a new test patch, if the overlay test patch is rejected. The number of trial test patch applications required shall be as many as necessary for the Contractor to demonstrate the ability to construct an acceptable trial overlay section and competency to perform the work. After three (3) failed trial applications, the engineer may elect to reject any portion of the procedure, including all overlay material/aggregate, application equipment, application technique, or contractor installing the overlay. Take possession of all material used in the test, dispose of it at no cost to the Department Protection of the Public. Ensure reasonable available engineering controls are in place to limit fugitive dust. Meet state, regional, and local government agencies requirements regarding control of dust generated by the blasting operation. During surface preparation and overlay application, take precaution to assure that traffic is protected from rebound, dust and construction activities. Provide appropriate shielding as required and directed by the Engineer. The Contractor is responsible for protecting traffic under and adjacent to the work on the bridge while removing deck concrete Limitations on Placing Operation. Do not schedule overlay placement if rain is anticipated to occur during the placement operation or during the curing time. The bridge deck surface must be dry prior to the application of the thin polymer (epoxy) overlay system. No visible moisture will be present on the bridge deck at the time of placement. Prior to overlay application determined by ASTM D Indicating Moisture in Concrete by the Plastic Sheet Method. Conduct moisture content test by taking the average of three (3) readings with in an 18 square area. Conduct one test and one additional test for every 1000 square feet of bridge deck to be overlayed during the operation. Conduct the modified ASTM D Indicating Moisture in Concrete by the Plastic Sheet Method by securely taping one 18 inch by 18 inch, 4 mil transparent polyethylene sheet to the deck for every 1000 square feet of bridge deck. Allow the plastic sheet to remain in place for a minimum of two (2) hours or the cure time specified in (first course), whichever is longer. No visible 6

7 moisture on the or under the polyethylene sheet is considered acceptable. A minimum temperature of the prepared surface, air, resin, and aggregate component temperature of 55 ᵒF (13 ᵒC) is require to start overlay operations. Suspend the overlay operation if the surface, air, or resin and aggregate component temperatures drops below 50 ᵒF (10 ᵒC). Do not apply the epoxy-based concrete overlay if the temperature is expected to drop below 50ᵒ F (10ᵒ C) within 8 hours after application, or the gel time of the mixed epoxy-based resin experienced becomes less than 10 minutes or when the difference between air temperature and dew point is less than 4 F (2.5 C). The maximum starting temperature at the surface or air temperature are to be less than 100 ᵒF (38 ᵒC). Suspend the overlay operation if surface or air rise above 110 ᵒF (43 ᵒC). Do not allow vehicular traffic on the first course. Do not allow vehicular traffic on any course during the cure period. Longitudinal joints should be placed as close as practical to marked lane edges. Longitudinal joints are prohibited within a wheel path. Do not place pavement makings until the epoxy-based resin has reached its final cure per section , Curing. Do not apply or cure polymer (epoxy) overlay on steel surfaces for temperatures less than 5 F above wet bulb temperature (dew point). Do not apply or cure polymer (epoxy) overlay steel surface contains rust, moisture or substances that would adversely affect overlay performance Transitional Area. If shown on the plans, create a transitional area on the approach slab using the same method in section preparation of existing deck. Remove ¼ to 5/16 of concrete adjacent to the pavement to remain and taper a distance of 3 feet to prepared surface. If shown on the plans, create a transitional area on the approach pavement. Prepare the surface per section and place the first lift 3 beyond the end of the deck the same width as the deck. Prepare the surface per section and place the second lift 6 beyond the end of the deck the same width as the traveled lanes Preparation of Existing Deck. Remove any unsound concrete and repairs areas in accordance with section , Bridge Decks Repairs. The surface area, as shown in Contract Documents, to receive the overlay is to be free of existing traction grooves, all pavement markings, any existing epoxy overlays, soils, dirt, curing compounds, weak mortar, and other contaminants. Prepared surface texture to meet Concrete Surface Profile (CSP) 7 determined by the International Concrete Repair Institute (ICRI). Vehicles other than approved construction equipment will not be permitted on sections of the deck where concrete surface preparation and overlay application operations have begun. Prevent contamination of the deck by all construction equipment or from any other source. Surface preparation all surfaces to which the overlay is to be boned not more than 8 hours prior to placing the overlay. Surface preparation consists of abrasive blast with the use a vacuum cleaner followed by compressed air swept to remove all dust and other loose material. Ensure after the surface preparation operation is completed, there is no visible evidence of oil grease, dirt, rust, loose particles, spent abrasives or other foreign material on any of the surfaces to be overlaid. 7

8 Test for moisture per this specification Section Repeat the moisture test after the work has been suspended for rain or if rain has fallen (on the project area) prior to overlay completion. The engineer may direct the contractor to conduct additional test. Cover exposed areas not to be overlaid with the epoxy-based concrete overlay, such as curbs (excluding 3 inches above deck surfaces), sidewalks, railings, parapets, drainage inlets, and expansion joint seals (Unless otherwise specified the overlay will be applied to expansion joint armor) with suitable coverings. Wet abrasive blasting is prohibited Epoxy-Based Resin Application. Combine and mix the base and hardener components as specified by the Manufacturer. Immediately after heating material to above 75 degrees, mixing, apply the mixed epoxy-based resin by a distributor, squeegee, paint roller, or combinations thereof. Apply the material at the point of dispensing with a minimum temperature of 75ᵒF (24 ᵒC) and a maximum temperature of 100ᵒF (38ᵒC). Apply the material smoothly, uniformly and continuously over 100 % of the deck surface. Cover all steel surfaces with epoxy-based resin within 6 hours following surface preparation. Apply the epoxy-based resin using a minimum of two (2) separate courses at the following application rates: Course Mixed Epoxy-Based Resin Application Rate gal./100 sq. ft. (Liters/Sq. Meter) (1.0) minimum (5.0) minimum Aggregate Application. Apply the aggregate at the specified rate, in a uniform manner, such that the aggregate saturates the epoxy base resin, ensure no wet spots appear. Apply the aggregate within five minutes after application of the mixed epoxy-based resin or as recommended by the Manufacture. The aggregate type, blend, and gradation will be the same in both courses and on the same bridge deck. Apply the aggregate using a minimum of two (2) separate courses at the following application rates: Course Aggregate Application Rate lbs./sq.yd. (Kg/Sq. Meter) (5.4+) (6.5+) Curing. Allow the overlay to reach final cure before subjecting it to traffic loads. Cure time is dependent upon the ambient and deck temperatures. Cure each course for the minimum cure period as follows unless longer periods are recommended by the Manufacturer. 8

9 Average temperature of deck surface, resin, and aggregate components in temperature ᵒF (ᵒC): Course (16-18) (19-21) (22-23) (24-26) (27-29) 85+ (30+) 1 4 hrs. 3 hrs. 2.5 hrs. 2 hrs. 1.5 hrs. 1 hrs hrs. 5 hrs. 4 hrs. 3 hrs. 3 hrs. 3 hrs. If temperatures fall below 60 ᵒF (16 ᵒC), the Engineer will require a longer curing period. If, at any time during the curing period, the temperature falls below 50 ᵒF (10 ᵒC), the work may be considered unsatisfactory and rejected Surface Preparation between Overlay Layers. After the first layer of coating has cured per Section , and prior to applying the second layer, remove ALL excess aggregate from the treated surface by sweeping, or vacuuming without tearing or damaging the surface; the material may be re-used if approved by the engineer and manufacturer. Only allow the necessary surface preparation construction equipment on the treated surface area. Provide appropriate protective measures to prevent contamination from equipment allowed on the deck during preparation and application operations. Prior to opening to traffic and applying pavement markings, clean expansion joints and joint seals of all debris and polymer. Remove excess aggregates from the treated surface (deck, expansion joints, and approach pavement) by sweeping, or vacuuming Sampling and Testing. After the overlay has cured per Section , check adhesion in accordance with ASTM C1583, Pull-Off Method. Provide the test equipment and perform all tests in the presence of the Engineer. Conduct one Pull-Off test per lot. The location of the Pull-Off test within each lot will be determined by the Engineer. A lot is defined as the following; 1. One lane of traffic for each span of the bridge (including adjacent shoulder, if under 8 feet in width) 2. Shoulders for each span, (if 8 feet or greater in width) 3. Approach slab(s) Perform pull-off tests no sooner than 12 hours after placement of complete overlay system per lot Defective Work. The Engineer may order removal and replacement of any newly overlay areas placed outside the limits in Section Limitation on Placing Operation; overlay area damaged by rainfall; overlay areas discovered to be unbonded (by tapping or chaining); overlay areas damaged by the Contractor s operation; or test areas rejected by pull off tests. Saw cut the unbonded or damaged areas to the top of the deck surface, remove the overlay with small air tools (15 pounds maximum) or shotblasting. Shotblast the concrete bridge deck surface at the unbonded area to remove contaminants meeting Concrete Surface Profile (CSP) 7 determined by the International Concrete Repair Institute (ICRI) and replace the overlay according to these specifications at no additional compensation. 9

10 Areas deemed to have insufficient aggregate cover by the Engineer, will be recoated with an additional layer of epoxy resin and aggregate according to standard placement procedures at no additional compensation Method of Measurement. The area of thin polymer overlay will be measured in square yards (square meters) of horizontal deck area (including vertical surface of barrier/curb), completed and accepted. Payment includes all labor, materials, and equipment required to complete the work. Repair all adhesion strength test areas, thickness test holes, or any debonded areas by filling with overlay material before final acceptance Basis of Payment. Payment for repaired items referenced in section will be made under Item 512, Concrete Repair by Epoxy Injection, or under Item 519, Patching Concrete Bridge Decks. Payment for completed and accepted quantities as measured above including surface preparation will be made at the contract bid price multiplied by a bond strength pay factor. For each lot, the unit price is multiplied by bond strength pay factor for the item Multi-Layer Epoxy Polymer Overlay. The bond strength of the three (3) pull-off specimens per lot will be averaged to determine the pay factor for each lot with the following exception: 1. If the tensile strength of a specimen is less than 250 psi and failure is in the concrete substrate and 100% of the test surface is covered with concrete, then the tensile strength used for that single specimen will be 250 psi. 2. Test locations over an existing deck patch will not be used for pay factors. If a test location was located over an existing patch a new location will be chosen by the Engineer, BOND STRENGTH PAY FACTORS Average Bond Strength of Lot * Percent Pay Greater than 245 psi 100% 235 psi psi 90% 225 psi psi 75% Less than 225 psi Reject *245 psi allows for a 2% margin of error (with 250 psi required) Item Unit Description 858 Square yard Thin Polymer Epoxy Overlay (Square meter) 858 Square yard (Square meter) Thin Polymer Epoxy Overlay, as per plan 10

11 Designer Notes (BDM): Thin Polymer Epoxy Overlays are used as a deck preservation methodology. They serve to seal the deck from chloride intrusion, seal cracks, and to increase surface friction. Thin bonded overlays can aid in minor grade corrections. Minor grade correction required to drain low spots or improve drainage will require additional polymer epoxy overlay courses not covered by the specification. The limits of and number of additional courses shall be specified in the contract plans. Use pay item as per plan, when specifying addition courses. Typically a concrete bridge deck with a deck General Condition Rating of 6 or greater would be considered a candidate for a polymer overlay. The deck candidates show signs of cracking and require minimal to moderate repair. Life expectancy for Thin Polymer Epoxy Overlays is estimated between 12 to 15 years. The pay item is Thin Polymer Epoxy Overlay and includes the following areas to be overlayed, concrete bridge decks, backwalls, approach slabs and barriers/curbs 3 inches above the deck. If additional areas are to be overlayed, add a note to the plans and change the pay item to include AS PER PLAN Depressions in the deck surface less than 1 1/2 inches can be filled with a mortar made from Polymer Epoxy Overlay material. If depressions in the deck are greater than 1 1/2 inches, add quantity for deck patching. Payment will be made under Item 519, Patching Concrete Bridge Decks. I f deck repairs are required, add quantity epoxy injection to seal larger crack (or to stop reflective cracking). Payment will be made under Item 512, Concrete Repair by Epoxy Injection. The plans should designate a transitional area approaching transverse expansion joints, ends of the decks or ends of approach slabs. The transition can be located on either the approach pavement or on the approach slab. Care needs to be taken when placing the overlay on approach slabs due to the moisture vapor within the concrete from the presents of ground water that may cause the overlay to prematurely delaminate. Designer should evaluate approach slabs in high water tables or have poor drainage attributes. If creating the transitional area at the ends of the approach slab, the transitional area will have a 3 feet length measured along the centerline and the width of the approach slab. If creating the transitional area on the approach pavement or no approach slab, the transitional area will have a 6 feet length measured along the centerline and the width of the traveled lanes. 11