439Bridge Deck Overlays

2.1 Latex for LMC . Provide latex admixture meeting the requirements of DMS -4640 , “Chemical Admixtures for

Concrete.” Store latex at temperatures between 40°F and 85°F. Do not allow latex to freeze.

2.2 Steel Fibers. Furnish steel fibers in accordance with ASTM A820. Dosage rate will be 40 lb./cu. yd., and

fibers will be 1 -1/2 in. long, unless otherwise shown on the plans.

2.3 Grout for CO or LMC . Provide grout for bonding new concrete to existing concrete consisting of equal parts

by weight of hydraulic cement and sand when shown on the plans. Mix with enough water to form a stiff slurry that can be applied using a stiff brush or broom to the existing concrete in a thin, even coating that will not run or puddle in low spots.

2.4 Materials for MLPO .

2.4.1 Sand . Furnish finely graded, oven- dry mason’s sand (for broadcast over crack sealant) that is compatible

with the MLPO as determined by the manufacturer of the overlay system.

2.4.2 Aggregate . Furnish aggregate (for polymer overlay) that conforms to the gradation shown in Table 1. Use an

angular -shaped aggregate with a Mohs scale hardness of 6 or greater. Use aggregates that are non- friable, non-polishing, clean, kiln- dried to a maximum moisture content of 0.2% by weight, and free of dirt, clay, asphalt, and other organic materials. All aggregate materials retained in the #8 sieve must have at least one mechanically fractured face. Aggregate not meeting the gradation requirements shown in Table 1 may be accepted if part of an overlay system. Table 1 Aggregate Gradation Requirements1 Sieve #4 Sieve #8 Sieve #16 Sieve #30 % by weight passing sieve 100% 30–75% 0–5% 0–1% 1. Based on the washed sieve analysis in accordance with Tex-200-F, Part II.

2.4.3 Resin for Polymer Overlay. Furnish a polymer resin composed of epoxy or modified epoxy . The resin (neat)

and resulting polymer overlay system (composite consisting of resin and aggregate) must comply with the property requirements shown in Table 2. Furnish a two -component, 100% solid, 100% reactive resin free of volatile solvents for epoxy -based resin. Formulate the resin to volumetric mixing proportions , such as one part “A” to one part “B,” in conformance with the overlay system manufacturer’s recommendations. 623 Table 2 Requirements for Resin and Polymer Overlay System Property Requirement1 Test Method Viscosity (neat) 7–70 poises Tex-614-J Gel time (neat) 15 min. Min Tex-614-J Compressive strength at 5 hr. (composite) 1,000 psi Min Tex-618-J Compressive strength at 48 hr. (composite) 3,000 psi Min Tex-618-J Tensile strength at 7 days (neat) 1,800 –5,000 psi Tex-618-J Resilience at 48 hr. (neat) 70% Min Tex-618-J Elongation at 7 days (neat) 30% Min Tex-618-J Bond strength (neat) 250 psi Min Tex-614-J Shore D hardness (neat) 60–70 ASTM D2240 Absorption at 24 hr. (neat) 1% Max ASTM D570 Thermal compatibility (composite) No delamination of overlay ASTM C884 with modifications; one cycle is 8 hr. at 60°C followed by 16 hr. at -21°C. Determine results after nine cycles. 1. Values are based on composite specimens or neat samples cured or aged and tested at 24°C (75°F).

2.5 Materials for PPC . Furnish polyester polymer concrete consisting of polyester resin binder and aggregates

with a compatible primer meeting the component and composite material properties specified. All components must be supplied collectively from the same manufacturer.

2.5.1 Primer. Furnish a wax -free low -odor high- molecular weight methacrylate (HMWM) primer consisting of a

resin, initiator, and promoter in accordance with Table 3 and the following. Furnish a prime coat promoter and initiator consisting of a metal drier and peroxide. If shipped separately from the resin, ensure that at no time the metal drier is mixed directly with the peroxide. Store containers in a manner that will not allow leakage or spillage from one material to contact the containers or material of the other. Table 3 Requirements for Primer Property Requirement Test Method Volatile content1 30%, Max ASTM D2369 Viscosity (Brookfield RVT with UL adapter, 50 RPM at 77°F)1 25 cps, Max ASTM D2196 Specific gravity1 0.90, Min ASTM D1475 Flash point1 180°F, Min ASTM D3278 Vapor pressure1 1.0 mm Hg, Max ASTM D323 Saturated surface -dry (SSD) bond strength, with primer2 700 psi, Min CA Test 551, Part 5 1. Tested before adding initiator. 2. Initiated polyester concrete tested at 12% resin content by weight of the dry aggregates.

2.5.2 Polyester Resin Binder . Furnish a polyester resin binder meeting the requirements of Table 4 and the

following:  unsaturated isophthalic polyester -styrene co- polymer suitable for a polyester concrete mixture with a resin content of 12% ± 1% of the weight of the dry aggregates,  contain at least 1% by weight gamma- methacryloxypropyltrimethoxysilane, an organosilane ester silane coupler, and  used with a promoter that is compatible with suitable methyl ethyl ketone peroxide and cumene hydroperoxide initiators. 624 Table 4 Requirements for Polyester Resin Binder Property Requirement Test Method Viscosity (Brookfield RVT with UL adapter, 50 RPM at 77°F)1 75–200 cps ASTM D2196 Specific gravity1 1.05– 1.10 ASTM D1475 Styrene content 40–50%, by weight ASTM D2369 Silane coupler1 1.0%, by weight Nuclear magnetic resonance spectrum Elongation 35%, Min (Type I specimen, thickness

0.25 + 0.03″ at rate = 0.45″/min.) ASTM D638

Sample conditioning: 18/25/50 + 5/70 ASTM D618 Tensile strength 2,500 psi, Min (Type I specimen, thickness 0.25 + 0.03″ at rate = 0.45″/min.) ASTM D638 Sample conditioning: 18/25/50 + 5/70 ASTM D618 1. Tested before adding initiator.

2.6 Aggregate . Furnish aggregate with the following properties:

 not more than 45% crushed particles retained on the #8 sieve;  fine aggregate consisting of natural sand only;  weighted- average aggregate absorption of no more than 1.0% when tested in accordance with AASHTO T 84 and T 85;  at the time of mixing with resin, moisture content of not more than one half of the weighted- average aggregate absorption when tested in accordance with AASHTO T 255; and  Aggregate with minimum Mohs hardness of 7. Comply with the requirements for the aggregate gradation shown in Table 5. Table 5 Aggregate Gradation Sieve Size Percent Passing 3/8″ 100 #4 62–85 #8 45–67 #16 29–50 #30 19–36 #50 5–20 #100 0–7 #200 0–3

2.6.1 Polyester Concrete. Provide polyester concrete with the properties shown in Table 6.

Table 6 Polyester Concrete Composite Mixture Properties Property Requirement Test Method SSD bond strength, without primer at 12% resin content by weight of the dry aggregate (at 24 hr. and 70 ±1°F) 500 psi, Min CT 551 Abrasion resistance 2 g weight loss, Max CT 550 Modulus of elasticity 1,000 –2,000 ksi ASTM C469 625 2.6.2. Sand for Friction Surface. Furnish commercial -quality blast sand that is determined by the manufacturer of the PPC overlay system to be compatible with the system. Furnish sand with not less than 95% passing the #8 sieve and not less than 95% retained on the #20 sieve. Sand must be dry at the time of application.

3.1 Surface Preparation Equipment .

3.1.1 Concrete Removal and Surface Preparation . Provide equipment meeting the requirements of Item 483,

“Concrete Bridge Deck Surfacing.”

3.1.2 Abrasive Blasting . Provide equipment capable of removing oil, dirt, slurry, curing compound, and laitance

from the surface of the concrete.

3.1.3 Sawing . Provide equipment capable of sawing concrete to the specified depth when required.

3.1.4 Power -Driven Chipping Tools . Provide tools not heavier than a nominal 30-lb. class for bulk removal of

concrete. Bulk removal and repairs will be in accordance with the requirements of Item 429.

3.1.5 Chipping Hammers . Provide chipping hammers not heavier than a nominal 15- lb. class to remove concrete

beneath any reinforcing bars.

3.1.6 Cleaning . Provide magnetic equipment followed by vacuum equipment to remove spent steel shot. Provide

vacuum equipment and equipment to supply compressed air free of oil and moisture for final cleaning of prepared surfaces unless otherwise approved.

3.1.7 Test Apparatus for MLPO . Provide all equipment to perform tensile adhesion test in accordance with

ASTM C1583.

3.1.8 Pressure Wash ing. Provide pressure washer capable of at least 5,000 psi for cleaning bridge surface before

CO.

3.2 Proportioning and Mixing Equipment .

3.2.1 Grout Mixer . Provide a volumetric continuous or mortar mixer.

3.2.2 CO. Follow applicable provisions of Item 421.

3.2.3 LMC . Follow th e applicable provisions of Item 421. Proportion and mix the latex -modified concrete using

volumetric or truck mixers capable of thoroughly mixing the ingredients to a uniform consistency meeting the requirements of the mix design. Volumetric mixers must be equipped with a flow meter for calibrating the water and latex supply portion of the mix. The mixer must also be equipped with a cumulative- type meter that can be read to the nearest 0.1 gal. The meters must be readily accessible, accurate to within 1%, easy to read, and controlled within the same calibrated unit.

3.2.4 MLPO . Furnish equipment suitable for mixing and placing the overlay system components recommended by

the manufacturer of the overlay system. Furnish paint rollers or notched squeegees to apply cr ack sealant and resin. Provide aggregate spreading equipment or methods capable of uniformly applying the aggregate so 100% of the polymer material is covered to excess.

3.2.5 PPC. Mix polyester concrete in a continuous automated mixer meeting the following requirements.

 Employ an auger screw and chute device capable of completely blending catalyzed binder resin and aggregates. 626  Employ a plural component pumping system capable of handling polyester binder resin and catalyst, adjustable to maintain proper ratios to achieve set and cure times within the specified limits.  Be equipped with an automatic metering device that measures and records aggregate and resin volumes. Record volumes at least every 5 min., including time and date. Submit recorded volumes at the end of shift.  Have a visible readout gauge that displays volumes of aggregate and resin being recorded.  Produce a satisfactory mix consistently during the entire application process.  Be calibrated using a method like that specified in Section 421.4.5.2., “Volumetric Mixers.”  Portable mechanically operated mixers of appropriate size, as recommended by the system provider and approved by the Engineer, may be used unless otherwise shown on the plans. Provide aggregate spreading equipment or methods capable of uniformly applying the aggregate so 100% of the overlay material is covered to excess.

3.3 Placing and Finishing Equipment .

3.3.1 Hand Tools . Provide enough hand tools for placing, consolidating, striking- off, and finishing stiff plastic

concrete.

3.3.2 Finishing Equipment for CO . Provide an approved surface vibrator moving ahead of the finishing machine

or an approved vibrating screed for overlay consolidation. Provide work bridges or other suitable facilities to perform all finishing operations.

3.3.3 Finishing Equipment for LMC . Provide a mechanical strike- off to ensure a uniform thickness of concrete in

front of the screed. Design the bottom face of the screed to minimize tearing of the surface of the plastic concrete. Provide a finishing machine capable of forward and reverse motion under positive control. Make appropriate provisions for raising the screeds to clear the screeded surface for traveling in reverse. Equip the finishing machine to travel on and screed off of any adjacent completed lane without damaging it. Use approved manual screeds and vibrators to consolidate and finish small or irregular areas inaccessible to the finishing machine. Provide work bridges or other suitable facilities to perform finishing operations and density checks.

3.4 Finishing Equipment for PPC. Place PPC by self -propelled slip- form paving machine modified or

specifically built to effectively place PPCs in a manner meeting the following requirements.  Employ a vibrating pan to consolidate and finish the PPC.  Be fitted with hydraulically controlled grade automation to establish the finished profile by using the average 15 ft. in front of and behind the substrate grade averaging devices on both sides of the new placement, or the sensor that works with string- line control. It is acceptable to match grade when placing lanes adjacent to previously placed polyester overlay.  Have enough engine power and weight to provide adequate vibration of the finishing pan while maintaining consistent forward speed.  Be capable of forward and reverse motion under its own power.  Provide side and end forms for supporting the screed and containing the overlay concrete. Roller screeds will not be permitted. When shown on the plans, or for small or irregular areas, as approved, the paving equipment described in this Section is not required.

4.1 General . Submit for approval a detailed work plan including equipment and manpower before beginning any

work. 627 The Engineer will inform the Contractor if night placements become necessary. No additional compensation will be provided for night placements of concrete. Provide enough lighting to make quality workmanship and adequate inspection possible during night placements. Lighting must be approved before operations begin. Provide enough labor and equipment for proportioning, mixing, placing, and finishing CO at a rate of at least 40 ft. of finished overlay per hour. Do not allow traffic other than construction equipment for the overlay on any portion of the prepared bridge deck before the overlay has been placed. Provide side and end forms for supporting the screed and containing the overlay concrete. Provide reinforcement, when required, in accordance with Item 440 and as shown on the plans. Place concrete only when the air or deck temperature is 40°F or above and the concrete temperature is between 50°F and 85°F. Do not cart concrete batches over the completed overlay until the over lay concrete has attained a 3,000- psi compressive or 425- psi flexural strength. If carts are used, provide timber planking of at least 3/4- in. thickness for the remainder of the curing period. Provide carts equipped with pneumatic tires. Do not interrupt curing operations to cart concrete over finished slabs. Open the structure with the completed overlay to normal construction traffic or to the traveling public in accordance with Section 422.4.1., “Schedule Restrictions and Inspection Hold-Points.”

4.2 Classification and Mix Design . Provide a mix design in accordance with Item 421. Use a water reducing

chemical admixture as necessary to achieve the desired consistency without exceeding the specified water -to-cementitious material ratio. Provide a mix design with an entrained air content of the fresh concrete of 6% with a tolerance of ±1% when tested in accordance with Tex -414-A or Tex-416-A together with the following requirements .

4.2.1 CO. Provide Class CO concrete with a coarse aggregate factor of at least 0.55 and add steel fibers at a rate

of 40 lb./cu. yd. unless otherwise shown on the plans .

4.2.2 LMC . Provide Class LMC concrete with a cement content of at least 658 lb. per cubic yard, a latex admixture

content of at least 24.5 gal. per cubic yard, and a water content of no more than 18.9 gal. per cubic yard. Provide a mix design using a coarse aggregate volume of 55– 65% by weight of the total aggregate. Use a commercially available anti -foaming agent with the polymer modifier as necessary to control the air content in the mix. Perform trial batching before placement date and verify slump, air content, temperature, compressive strength, and consistency can be met. If conditions change before placement date (aggregate moisture, excessive temperature changes, or other factors that may affect consistency), additional trial batching will be required as directed. This work will be subsidiary to this Item.

4.3 Surface Preparation . Do not scarify concrete surfaces with a grooved or tined finish unless shown on the

plans. Prepare these surfaces by abrasive blasting or water -injected abrasive blasting as required to remove dirt, oil, curing compound, laitance, surface mortar, and other material that would inhibit bonding of the overlay, but leave the striations intact. Prior to milling or hydro- demolition, sound the bridge deck to verify limits of overlay. Shallow saw -cut the perimeter of the overlay limits. Do not damage existing reinforcing. Replace damaged reinforcing at no additional cost to the Department. Scarify the surfaces of slabs to be rehabilitated to the depths shown on the plans using the method specified in accordance with Item 483. Remove and dispose of deteriorated or delaminated areas of concrete as shown on the plans or as determined using a sounding hammer, chain drag, or other acceptable device, and by visual inspection after scarifying as approved. Remove and repair deteriorated concrete below the indicated depth of scarification in accordance with Item 429. Use only hydraulic -cement concrete for these repairs. Ensure the repaired surface is flush with the 628 surrounding scarified surfaces. Allow the repair concrete to cure before placing the overlay concrete unless approved otherwise. When approved, placing repair concrete in partial depth deck repairs m ay be concurrent with placing the overlay concrete. Use a jackhammer not heavier than a nominal 30- lb. class to remove deteriorated concrete in small areas not accessible to the mechanical scarifier, and to spot -remove small areas of deteriorated concrete to a depth down to the existing top reinforcing steel. This class of jackhammer may also be used for concrete removal between existing reinforcing bars to a greater depth. Use chipping hammers not heavier than a nominal 15- lb. class to remove concrete from beneath any reinforcing bars near the perimeter of the removal area. Avoid cutting, stretching, or damaging exposed reinforcing steel by direct impact of these power tools. Repair or replace reinforcing steel damaged during the concrete removal process at no additional expense to the Department. Operate all jackhammers and chipping hammers at an angle of 45° or less measured from the surface of the slab. Do not damage reinforcing steel. If more than one half of the diameter of the reinforcing bar is exposed and the bar is corroded around the circumference, adjacent concrete is rust stained, or the bar is debonded from the substrate concrete, chip away concrete or water blast to provide a minimum 3/4- in. clearance using a 15-lb. max chipping hammer. Clean al l exposed reinforcing steel, scarified surfaces, and newly exposed concrete surfaces including construction joints against curbs or parapet walls by wet or dry abrasive blasting. Blast corroded reinforcing steel to gray metal. Remove and place all blast debris at an approved disposal site. Repair or replace damaged reinforcing steel as required. Place, support, and tie new reinforcing steel on prepared surface in accordance with Item 440 when shown on the plans. Complete surface preparation within 48 hr. of overlay placement. Multiple mobilizations may be required and will be subsidiary to this Item. If placement does not occur due to weather or other scheduling conflicts, pressure wash deck surface using at least 5,000- psi pressure washer.

4.4 Placing and Finis hing Concrete . Grade the screed rails or headers to ensure the concrete is finished to the

required profile. Place the rails or headers outside the area to be overlaid unless otherwise approved. Provide anchorage of headers or supporting rails for horizont al and vertical stability as necessary. A hold- down device anchored into the concrete will not be permitted unless the concrete is to be subsequently overlaid. Obtain approval for plans for anchor support of headers or rails before beginning work. Provide the overlay thickness shown on the plans. Adjust the screed and screed rail as necessary to provide the approved grade and required thickness. Check the clearance between the screed and existing surface for nonreinforced overlays by attaching a filler bloc k with a thickness of 1/8 in. less than the overlay thickness to the bottom of the screed. Pass the screed over the area to be overlaid with the filler block in place. Correct any areas with insufficient clearance by adjusting the screed and rail system or by chipping or scarifying as approved. Check screed clearance and reinforcement cover for reinforced overlays as approved. Clean areas where removal occurs by pressure washing using at least 5,000 psi. Construct longitudinal joints at locations shown on the plans or as approved. Construct a straight and vertical edge at transverse and longitudinal construction joints. Saw joints before placing the adjacent overlay course. Install expansion joints in the overlay at the same locations as the expansion joint s in the deck. Do not saw overlay to re- establish expansion joint conditions. Isolation forming of expansion joints for overlays is required. Provide clean surface before moistening surface to receive overlay by water blasting to remove all dust, spent abr asives, laitance, and other contaminants that can reduce bond strength of overlay to concrete surface. Pressure wash the deck surface using at least 5,000 psi within 48 hr. before CO placement. Cover deck surface to receive CO with polyethylene sheeting to maintain moisture. The plastic sheeting will be rolled up as the overlay placement equipment passes over it so that the cleaned surface is not exposed to 629 wheels, dirt, oil, grease, or any other contaminants. Clean contaminated areas and areas exposed for more than 36 hr. again as directed. Maintain SSD condition for at least 8 hr. before overlay placement. Moisten the prepared surface to a near -SSD condition before placing the overlay concrete. Remove standing water from the surface before placing the overlay concrete. Do not use bonding grout unless otherwise shown on the plans or in accordance with this Item. When bonding grout is required, moisten the prepared surface to a near -SSD condition before placing bonding grout. Scrub a thin coating of grout into the prepared surface immediately before placing the concrete. Ensure all surfaces including vertical joints receive a thorough, even coating and no excess grout collects in pockets. Apply the grout so it does not become dry before it is covered with concrete. Additional surface preparation and placement of similar approved material will be required in areas where Contractor’s forming operations or other actions prohibit the placement of overlay concurrently with initial phasing. Place and mechanically strike off the overlay concrete slightly above the final grade. Follow this strike- off by mechanically consolidating and screeding the surface to the final grade. Vibrate all concrete into the corners and angles of the edges. Adequately consolidate overlay material around exposed reinforcing steel. Hand- finish the surface with a float as necessary to produce a tight, uniform surface. Assure dense, watertight construction joints by properly consolidating the concrete and float -finishing the top surface of the joint flush with the adjacent concrete. Meet the straightedge and finishing requirements in accordance with Section 422.4.7., “Finish and Interim Curing of Bridge Slabs,” for the finishing of the CO .

4.5 Curing. Apply wet burlap to cure the overlay as soon as possible after the concrete has been textured.

Overlay that dries out or cracks before the wet burlap is applied will be rejected. Keep the burlap continuously wet for 48 hr. for LMC s and for 4 days for COs. Allow LMC to air -cure for an additional 48 hr. before opening to traffic. Water -cure the CO in accordance with Section 422.4.8., “Final Curing,” for an additional 4 days. Do not place traffic on overlay until required strength is obtained. Maintain the surface temperature of the concrete above 40°F for the required curing period. Remove and replace rejected overlay concrete at no additional cost to the Department.

4.6 Final Surface Texture. Provide final surface texture to hardened concrete surface in accordance with Section 422.4.11, “Final Surface Texture. ”

5.1 Contractor Submittals . Submit to the Engineer the following documentation and obtain approval before

work commences .

5.1.1 Product Data . Submit a list of materials to be used. Provide manufacturer’s product data sheets that include

material specifications for the proposed polymer overlay system; mechanical, physical, and chemical properties; environmental durability; limitations; maintenance instructions; and general recommendations pertinent to storage, mixing, application, cleanup, and disposal of materials. Submit a resin mix design that includes the name and type of all ingredients, the mix ratios to be used, and the application rate for each material. Include in the submittal a chart showing the expected cure times (in minutes) at the corresponding temperatures between 40°F and 100°F (in 10°F increments) for the proposed mix designs.

5.1.2 Certification of Compliance . Provide a certificate of compliance from an independent, nationally recognized

laboratory stating the materials to be used meet the requirements of this specification. Furnish samples of the materials to be used as required. 630 5.1.3. Safety Data Sheets (SDS) . Provide manufacturer’s SDS f or all materials to be used onsite and certification that the materials are in conform ance with local, state, and federal environmental and worker’s safety laws and regulations.

5.1.4 Work Plan . Submit a work plan for constructing the overlay , including at least the following:

 proposed equipment, materials, and procedures for preparing the surface and placing the overlay;  proposed removal and replacement of existing non- compatible deck repair materials;  repair procedures for patching deteriorated areas and repair ing cracks exposed by surface preparation; and  an anticipated schedule for traffic control. The work plan must meet the approval of the manufacturer of the polymer overlay system. Any deviations from the application in accordance with this specification must be approved.

5.1.5 Technical Support Representative. Submit name and qualifications of overlay system manufacturer’s

representative who will be on the jobsite at initiation of work. The Engineer may request the manufacturer’s representative return to the jobs ite to address issues that may arise during the work.

5.2 Handling of Materials . Transport and store polymer materials in their original containers in conformance

with the manufacturer’s recommendations and requirements. Clearly mark containers as “Part A —Cont ains Resin” or “Part B —Contains Curing Agent,” and include the following information on each container:  name of product,  name and address of manufacturer,  mixing proportions and instructions,  lot and batch numbers,  date manufactured, and  quantity contained. Store aggregates in a clean and moisture- free atmosphere that is protected from all potential sources of contamination.

5.3 Deck Repair . Repair the deck in accordance with Item 429 before surface preparation and as shown on the

plans. Use only repair materials that are compatible with the crack sealant and overlay systems that the system manufacturer has determined. Do not use phosphate- based repair materials unless the overlay system manufacturer determines them to be compatible.

5.4 Surface Preparation . Prepare the entire concrete deck surface after all repairs have cured in conformance

with the repair material manufacturer’s recommendations by removing weak concrete, asphaltic materials, oils, dirt, rubber, curing compound, paint, carbonation, laitance, weak surface mortar, and other potentially detrimental materials that, in the opinion of the overlay system manufacturer’s representative or the Engineer, would prevent proper bonding to or curing of the overlay material. Use power -driven hand tools only in areas where mechanical surface preparation equipment cannot reach. Conduct all hand tool operations before using mechanical surface preparation equipment. Select a surface preparation technique such as size and flow of abrasive or water pressure, travel speed, and number of passes that will provide a surface profile equivalent to International Concrete Repair Institute Guide No. 03732, Profile 5 or higher. Use advanced surface removal methods in accordance with Item 483 when shown on the plans. Use compressed ai r equipment to clean all dust, debris, and concrete fines from the deck surface and vertical faces of curbs and barrier walls up to a height of 1 in. above the overlay after hand tool and mechanical surface preparation is complete. Do not allow public traf fic onto any portion of the deck that has been prepared and cleaned, or onto any area where all courses have not been placed and allowed to fully cure. Overlay application equipment only is allowed to drive on the prepared deck surface or on any intermediate course during the overlay application if these surfaces are not contaminated or otherwise damaged. 631 Protect all prepared surfaces from subsequent contamination, and remove any contamination found on the deck or intermediate courses after initial preparat ion. The deck surfaces will be inspected for presence of contaminants immediately before placing sealant or any course of the overlay system. Apply the sealant or first course of the overlay within 24 hr. of surface preparation and place all intermediate c ourses of the overlay within 7 days of initial surface preparation.

5.5 Tensile Adhesion Testing. Conduct direct pull -off tests in accordance with ASTM C1583 to determine the

adequacy of the selected surface preparation ( e.g., size of shot, flow of shot, forward speed of blast machinery, number of passes, and blast pressure) and cleaning methods. Conduct these tests when the surface temperature is below 80°F. Core through the test overlay to a depth of 0.5 in. into the underlying concrete. Conduct one tensile adhesion test for each span or 500 sq. yd., whichever is smaller. The Engineer will determine test site locations for each representative portion of deck. In addition to representative portion tests, the Department may require additional tensile adhesion tests on areas inaccessible to mechanical surface preparation equipment. The Contractor must remove residual test materials adhering to the deck, make necessary adjustments to the surface preparation methods, and retest all representative portions with failing test results, at no additional cost to the Department, until one passing tensile adhesion test result (from three pull-off tests) is obtained for each area tested. One tensile adhesion test result is the average of three pull-off tests conducted over a 1 × 3- ft. test site prepared with at least one layer of polymer. Surfaces with tension adhesion test results demonstrating average tensile bond strengths of at least 250 psi are considered acceptable.

5.6 Application of Polymer Overlay . Do not place polymer overlay on new hydraulic cement concrete that is

less than 28 days old unless otherwise approved. Place polymer overlay on repairs only after completion of curing of the repair material and with the concurrence, in writing, of the polymer overlay system manufacturer. Allow the deck to dry fully before applying polymer overlay. Identify moisture in the deck using a plastic sheet left taped in place for at least 2 hr. (in accordance with ASTM D4263) or by other approved methods. Remove all loose sand or aggregate and attain approval before placement of each polymer overlay course. Mix, place, and cure the polymer overlay materials in conformance with the overlay system manufacturer’s written recommendations. Do not apply polymer overlay if the ambient air temperature is expected to drop below the overlay system manufacturer’s recommended application temperature range within 8 hr. after application or if the gel time is expected to drop below 10 min. Broadcast aggregate onto the still fluid resin binder until a dry layer of aggregate is present over the entire surface. Immediately broadcast additional aggregate until a dry surface is established if wet spots develop. Accomplish all aggregate broadcasting while binder is still fluid. Cure each course of overlay until vacuuming or sweeping can be conducted without tearing or otherwise damaging the overlay surface. Repair at no additional cost to the Department any intermediate courses in which the treated surface is damaged, is contaminated, or does not receive adequate aggregate before gelling to create an intermediate surface compatible with the next overlay course as the overlay system manufacturer determines. Repair damaged areas in conformance with the overlay system manufacturer’s recommendations at no additional cost to the Department if the final poly mer overlay surface is damaged or marred. The nominal finished overlay thickness is at least 3/8 in. measured from the highest point on the deck surface to the peaks of the aggregate. Apply the polymer with aggregates in multiple courses ( at least two for epoxy systems) as prescribed by the overlay system manufacturer but at rates no less than shown in Table 7. Stagger and overlap longitudinal joints between successive courses so no ridges form. 632 Table 7 Polymer and Aggregate Application Rates Course Polymer (gal./100 sq. ft.) Aggregate (lb./sq. yd.) Epoxy 1 Not less than 2.5 >10 Epoxy 2 Not less than 5.0 >14 Protect all bridge deck expansion joints from intrusion of polymer overlay materials. Remove overlay over all expansion joints within 12 hr. of application and before opening the overlay surface to traffic. Removal may be accomplished by scoring the overlay before gelling, by saw -cutting after curing, or by other method approved by the overlay system manufacturer. Obtain approval to open any course to traffic. Obtain approval of cleaning and surface preparation methods for initial courses that were opened to traffic before the final course was applied. Do not allow construction traffic on the final course until it has cured enough to prevent damage by wheel loads. Minimum curing periods will be in accordance with the submitted curing time chart.

5.7 Repair of Defects. The Department will examine the completed work for defects. Immediately repair or take corrective action for delaminations, raveling, weathering, incomplete aggregate coverage, or other defects

found during the Department’s examination.

6.1 Contactor Submittals . Submit for approval a detailed work plan including all product data, equipment, and

manpower before beginning any work.

6.1.1 Product Data. Submit a list of materials to be used. Provide manufacturer’s product data sheets that include:

 material specifications for the proposed polymer overlay system;  mechanical, physical, and chemical properties;  environmental durability;  limitations;  maintenance instructions; and  general recommendations pertinent to storage, mixing, application, cleanup, and disposal of materials. Submit a mix design that includes the name and type of all ingredients, the mix ratios to be used, and the application rate for each material. Include in the submittal a chart showing the expected cure times (in minutes) at the corresponding temperatures between 40°F and 100°F (in 10°F increments) for the proposed system components.

6.1.2 Certification of Compliance . Provide a certificate of compliance from an independent laboratory stating the

materials to be used meet the requirements of this specification. Furnish samples of the materials to be used as required.

6.1.3 SDS. Provide manufacturer’s SDS for all materials to be used onsite and certification that the materials are in

conformance with local, state, and federal environmental and worker’s safety laws and regulations.

6.1.4 Work Plan . Submit a work plan for constructing the overlay, including at least the following:

 proposed equipment, materials, and procedures for preparing the surface and placing the overlay;  proposed removal and replacement of existing non- compatible deck repair materials;  repair procedures for patching deteriorated areas and repairing cracks exposed by surface preparation; and  an anticipated schedule for traffic control. The work plan must meet the approval of the manufacturer of the overlay system. Any deviations from the application in accordance with this specification must be approved. 633 6.1.5. Technical Support Representative. Submit name and qualifications of overlay system manufacturer’s representative who will be on the jobsite at initiation of work. The Engineer may request the manufacturer’s representati ve return to the jobsite to address issues that may arise during the work.

6.2 Handling of Materials . Transport and store polymer materials in their original containers in conformance

with the manufacturer’s recommendations and requirements. Clearly mark containers by component and corresponding to sequence of work and include the following information on each container:  name of product,  name and address of manufacturer,  mixing proportions and instructions,  lot and batch numbers,  date manufactured, and  quantity contained. Store all materials in a cool, dry location protected from all potential sources of contamination or moisture and in their original containers in conformance with the system manufacturer’s recommendation to ensure their preservation until used in the work. The shelf life for liquid materials stored out of direct sunlight and at temperatures 80°F and below must be at least 12 mo. Applicable fire codes may require special storage facilities for some components of the overlay system.

6.3 Application . When night work is necessary, no additional compensation will be provided for night

placements of concrete. Provide enough lighting to make quality workmanship and adequate inspection possible during night placements. Lighting must be approved before operations begin.

6.3.1 Trial Application . Before constructing the overlay, conduct one or more trial applications on the prepared

substrate to demonstrate proper initial set time and the effectiveness of the surface preparation, mixing, placing, and finishing equipment proposed. Each trial application will be at least 10 ft. long, at the planned paving width and specified overlay thickness, and on the deck to be overlaid. The Engineer will approve the locations of the trial applications. As approved, successful trial applications may be retained as the final product. If the cleaning practice, materials, installation, finishing, or texturing are not acceptable, remove the failed trial application and reinstall the trial application at no additional cost to the Depart ment until satisfactory results are obtained. Conduct as many trial applications as necessary to demonstrate th e ability to construct an acceptable trial overlay section and competency to perform the work. The installer, system provider, and proposed equipment and techniques may be rejected if not shown to be acceptable after three failed trial applications. Perform tensile adhesion test 24 hr. after the placement of the trial application in accordance with ASTM C1583 to assure that the overlay adheres to the prepared surface. Report the average of three successful tests. Test cores must be drilled through the overlay and into the substrate at least 0.5 in. The minimum bond strength on normal weight concrete substrates will be 250 psi with a concrete subs trate failure area greater than 50% of the test area. Repair all bond strength test locations with polyester concrete in accordance with this Item.

6.3.2 Surface Preparation . Prepare surface by shot blasting in accordance with Item 483. Remove dirt, slurry,

curing compound, laitance, and any other de- bonding material from the surface of the concrete. Keep vehicular traffic from shot -blasted surface unless required by the overlay operation and approved. Clean concrete substrates that have contaminants that may int erfere with the bonding or curing of the overlay before placing the overlay, at no additional cost to the Department. Apply primer and overlay only to clean and dry concrete substrate. 634 All steel surfaces that will be in contact with the overlay must be cl eaned in accordance with SSPC -SP No. 10, “Near -White Blast Cleaning,” except that wet blasting methods are not allowed.

6.3.3 Application of Primer . Do not begin application of the primer until the substrate is visibly surface dry, free of

water and moisture. ASTM D4263 modified for 2 hr. may be used to verify dryness at the discretion of the Engineer in cases when surface dryness is difficult to determine. The substrate surface temperature must be between 40 and 100°F at the time of primer and overlay placement. Night work may be required when temperatures cannot be met during the day. Before applying the HMWM prime coat, ensure the area is completely dry and blown clean using oil -free compressed air. Mix and apply primer in conformance with the system provider’s recommendations. Apply primer within 5 min. of mixing initiator and resin at a rate of approximately 90– 100 sq. ft./gal. or as otherwise recommended by the system provider. Apply primer by flooding and uniformly spreading to completely cover all surfaces to receive overlay, including any adjacent vertical surfaces. Avoid heavy application that results in excess puddling. Remove or distribute excess material to meet the recommended application rate. Reapply primer to any areas that appear visibly dry before overlay placement.

6.3.4 Application of Polyester Concrete . Mix and apply the polyester concrete in conformance with the system

provider’s recom mendations. Place concrete only when the air or substrate temperature is between 40°F and 100°F and the polyester concrete temperature is between 40°F and 100°F. Apply polyester concrete after 15 min. and within 2 hr. of placing the primer. Place the poly ester concrete before gelling or within 15 min. following addition of the initiator, whichever occurs first, or as recommended by the system provider. The polyester concrete mixture must have an initial set time of 30– 90 min. Initial set has occurred when the in-place polyester concrete cannot be deformed by pressing with a finger. An initial set of less than 20 min. will be cause for rejection at the Engineer’s discretion. If the initial set is not within 90 min., remove and replace the material at no additional cost. Consolidate and finish the polyester concrete using placement equipment as defined herein to strike off the polyester concrete to the required grade and cross -section as shown on the plans. Place the polyester overlay at a profile necessary to meet the desired grade and cross -section as shown on the plans, with a minimum thickness of 3/4 in. Termination edges of the overlay may require application and finishing by hand trowel due to obstructions such as a curb. Isolate expansion joints befor e overlaying or saw within 4 hr. after overlay placement, as approved. Provide enough labor and equipment for proportioning, mixing, placing, and finishing CO at a rate of at least 40 ft. of finished overlay per hour.

6.3.5 Application of Abrasive Sand Finish . Apply the abrasive finish sand evenly on the finished overlay surface

at a rate of at least 2.2 lb. per square yard by broadcasting immediately after the overlay placement before gelling. Adjust rate of application as necessary to ensure complete coverage.

6.4 Curing. Cure overlay sufficiently before being subjected to loads or traffic of any nature that may damage the

overlay. Cure time depends on ambient and substrate temperatures and also initiator and accelerator levels used at the time of mixing. The over lay is considered cured to a traffic -ready state after 4 hr. following finishing, or as approved by manufacturer and the Engineer. Methods to validate traffic -ready state in less than 4 hr. may be submitted by the manufacturer for approval. A Schmidt hammer reading of not less than 25 on a properly calibrated Schmidt hammer is an acceptable method to validate traffic -ready state. 635 6.5. Surface and Thickness Requirements. Variable thickness overlay placement may be required to account for variations in substrate profile to meet the desired grade and cross -section as shown on the plans. Contractor is responsible for the ride quality of the finished surface. Acceptance criteria as defined in Section 422.4.10, “Defective Work,” will be used and enforced for this wor k. Correct any surfaces that fail to conform to the specified tolerance by diamond grinding. Do not diamond grind until at least 24 hr. after placement of the overlay. If the Engineer determines that the minimum thickness has not been attained, apply an additional layer, at least 1/4 in. thick, after the overlay has cured for at least 4 hr., and applied as recommended by the system provider and approved at no additional cost to the Department. To ensure adequate pavement friction, the completed overlay surface must be free of any smooth or glassy areas such as those resulting from insufficient quantities of abrasive finish sand. Repair any such surface defects as recommended by the system provider and approved. Fill surface cracks in sound, bounded polyester COs with properly catalyzed HMWM primer material.

6.6 Grooving. When shown on the plans, groove surface in accordance with Section 422.4.11., “Final Surface

Texture.”