SPECIFICATION GUIDELINES: RAPID SET REPAIR POLYMER
Portland Cement Concrete and
Asphalt Concrete Pavements1. GENERAL REQUIREMENTS
1.1 SCOPE
1.1.1 This specification covers the repair of pcc and ac pavements and bridge decks using a rapid curing polyurethane resins. The resin penetrates cracks and can be percolated over preplaced aggregates for deep spall repairs. It is also useful for surface application to fire damaged pavements and ac pavements having alligator cracking. The provisions of this Standard shall govern unless otherwise specified in the contract documents.1.2 REFERENCE ORGANIZATIONS
AASHTO American Association of State Highway and Transportation Officials
444 N. Capitol Street NW-Suite 249
Washington, DC 20001
ACI American Concrete Institute
P.O. Box 19150
Detroit, MI 48219-0150
ASTM American Society for Testing and Materials
1916 Race Street
Philadelphia, PA 191031.3 REFERENCE STANDARDS
ASTM C33 Specification for Concrete Aggregates
ASTM C39 Test Method for Compressive Strength of Cylindrical Concrete Specimens
ASTM D41 Test Method for Vulcanized Rubber and Thermoplastic Rubbers and
Thermoplastic Elastomers-Tension
ASTM D618 Method for Conditioning Plastics and Electrical Insulating Materials for Testing
ASTM D624 Test Method for Tear Strength of Conventional Vulcanized Rubber and
Thermoplastic Elastomer
ASTM D638 Test Method for Tensile Properties of Plastics
ASTM D648 Test Method for Deflection Temperature of Plastics Under Flexural Load
ASTM D792 Test Method for Specific Gravity (Relative Density) of Plastics by Displacement
ASTM D2369 Test Method for Volatile Content of Coatings
ASTM D2393 Test Method for Viscosity of Epoxy Resins and Related Components
ASTM D2240 Test Method for Rubber Property-Durometer Hardness
AASHTO T84 Specific Gravity and Absorption of Fine Aggregate
AASHTO T85 Specific Gravity and Absorption of Coarse Aggregate1.4 SUBMITTAL OF PROCEDURES
1.4.1 Detailed procedures - Submit detailed procedures for the production, transportation, placement, finishing, and curing of the rapid setting urethane resin. In the submittal include handling, storage, and safety procedures to be implemented .
1.4.2 Trial Installation - Submit detailed procedures for installation of a trial section to demonstrate the proper operation of the batching, transport, and finishing equipment. These procedures shall include the batching methods and calibration procedures, if applicable.2. MATERIALS
2.1 RAPID SETTING POLYURETHANE (Elastic Cement AC Grade)
The rapid setting polyurethane resin (Elastic Cement AC Grade) is two liquid components mixed in equal volumes. Component A consists of aromatic polyisocyanates and petroleum hydrocarbons. Component B consists of polyols, catalysts and petroleum hydrocarbons. The resins shall have the following proper ties:APPLICATION
APPLICATION CURED Component "A" "B" Specific Gravity
ASTM D-7921.06to1.10 Ratio, A:B, weight or volume 1 1 Hardness, Durometer D
ASTM D-224045to65 Viscosity @ 73 deg. F, cps 70 180 Tensile Strength, psi
ASTM D-4121600 Appearance Brown Black Elongation at Break %
ASTM D-412140 Specific Gravity @ 73 deg. F 1.10 1.03 Tear Strength
ASTM D-624150 Compression Strength, psi
ASTM C-39800 MIXED Pot life @ 73 deg. F (approximate) 60 Seconds Cure Time @ 73 deg. F (approximate) 10 Minutes Mixed Color Black 2.2 PRE-PLACED AGGREGATE
Aggregate size selection is based on the repair depth and shall be in accordance with the following:Depth of Repair Aggregate Size
Less than 1 1/2 in 1/4 in.
1 1/2 to 3 in. 1/2in.
Greater than 3 in. 1 in.Aggregate for preplaced concrete repair shall conform to the requirements of ASTM C33-90 "Standard Specification for Concrete Aggregates" with the following aggregate grading: Aggregate absorption shall not exceed 1 percent as determined by AASHTO T84 and T85. At the time of application, the moisture content of the aggregate shall not exceed one-half of the aggregate absorption.
2.3 SKID RESISTANT AGGREGATE
Commercial quality dry blast sand having a gradation between No.4 and No.16 mesh shall he applied to the surface of the repair to provide a skid resistant surface. The sand shall conform to the dryness requirements in these special provisions at the time of application.3. EXECUTION
3.1 GENERAL3.1.1 Preparation Before Concreting - This work shall consist of installing rapid setting urethane resin to repair spalls, cracks and surface scarring of ac and pcc pavements in accordance with the details shown on the plans and these special provisions. The entire area to receive resin shall be cleaned in accordance with these provisions. Traffic shall not be allowed on the clean surface. All laitance and surface contaminants including but not limited to rust, oil, paint, joint material, and other foreign material shall be removed from the surface of the existing concrete. Water may he used to aid in the cleaning but the concrete shall have been dry for not less than 24 hours before placing the resin.
Equipment shall be fitted with suitable traps, filters, drip pans or other devices to prevent oil, fuel, grease or other deleterious material from being deposited on the existing deck. Any area that becomes contaminated after cleaning shall be re-cleaned at the Contractor's expense. Just prior to placing the resin, the surface shall be cleaned by compressed air blasting to remove dust and any other loose material. Expansion joints shall be adequately protected and isolated prior to placing the repair as approved by the engineer.3.1.2 Placement temperature - The air temperature shall be between 0 deg. F and 100 deg. F at the time of installation. The resin Component and aggregate temperatures shall be maintained between 50 deg. F and 85 deg. F immediately prior to installation. For temperatures less than 40 deg F, the aggregate and resin shall be maintained above 60 deg F immediately prior to use.
3.1.3 Mixing - The resin shall be mixed in mechanical equipment designed for proper metering and dispensing. Hand mixing shall not be allowed. The mixing equipment shall be approved by the resin manufacturer. The equipment shall be well-maintained, clean, and operating properly. The mixing equipment shall be properly calibrated and tested prior to installation of repairs. A minimum of one gallon or resin shall be mixed and dispensed prior to beginning work. The pump calibration shall mix the components to within 5 percent.
3.1.4 Material Safety - Consult and follow handling and safety directions of the manufacturer and Material Safety Data Sheets. Protective clothing shall include wearing rubber gloves, long sleeve shirts, long pants, proper boots, and safety glasses.
3.1.5 Restoration of Traffic - Traffic may be allowed on the repaired area after the resin has cured sufficiently to resist loss of aggregate. The following times are provided as typical guidelines.
Ambient Temperature (deg. F) Typical time to Traffic (mm.)
70 15
50 40
30 703.1.6 Finishing- The finishing equipment used shall strike off the resin to the established grade and cross-section. The resin shall completely fill the voids and the aggregates shall be well compacted. Areas to receive an abrasive sand finish shall be broadcast with dry skid resistant aggregate. The sand finish shall be applied immediately after resin strike-off and before gelling occurs to provide a minimum coverage of 0.8 pounds per square yard. The surface texture of the repair shall be uniform and the sand shall be well adhered.
3.1.7 Trials - If required, Prior to constructing the repair, one or more trials shall be placed on a previously constructed concrete base to demonstrate the effectiveness of the mixing placing and finishing equipment proposed. The length shall be sufficient to demonstrate production run construction techniques. Conditions during the trial, personnel, and equipment used shall be similar to those expected and to be used for the construction of the repair.
3.2 CRACK AND SPALL REPAIRS IN PCC PAVEMENTS
3.2.1 Surface Preparation - The area to be repaired shall be clean and dry. All paint, oil, grease, form-release compounds, curing agents, bitumen, laitance, and caulking materials shall be removed prior to repair. Spalled areas shall cleaned by abrasive blasting. Water blasting shall not be allowed. Cracks and spalls shall be blown clean using oil-free compressed air. The pavement shall be dry prior to application of repair. If emergency repairs are required to wet pavement, the repair location shall be thoroughly dried using a heat lance or hot air. Repairs shall not be performed during periods of rain. The edges of spalls larger than 1 sq. ft. shall be saw-cut to a minimum depth of 3/4 in. and the concrete shall be chipped to produce a vertical or undercut edge. Care shall be taken not to cut reinforcing steel.3.2.2 Placement for Spall Repair- Fill the spalls with clean, dust-free, dry aggregate to final grade or 1/2 in. below final grade. Spalls greater than 4 in. in depth shall be filled in lifts not exceeding 3 in. The lifts shall be placed continuously ensuring that the bond interface and spall is completely saturated with resin and that no hardening of the pervious lift occurs prior to placing the subsequent lift. If the resin hardens prior to placing additional lifts the repair will be removed to sound concrete, abrasively blasted and the repair shall be reinstalled. The aggregate size for spall repairs shall be determined based on the depth of the repair as specified in Section 2.3-Aggregate of these Special Provisions. Flood the aggregate completely and squeegee the surface smooth. Immediately add skid resistant sand prior to resin hardening.
3~2.3 Placement for Crack Repair - Flood prepared cracks with resin to refusal. If the resin penetrates into the crack, continue flooding until full. Add skid resistant sand to resin prior to hardening.
3.3 REPAIR OF ALLIGATOR CRACKS, SPALLS, AND RAVELED AC PAVEMENTS
3.3.1 Surface Preparation - Remove dirt and debris by blowing area clean with oil-free compressed air. The area to be repaired shall be clean and dry. All paint, grease, and caulking materials shall be removed prior to repair. Spalled areas shall be cleaned by abrasive blasting. Water blasting shall not be allowed. Cracks and spalls shall be blown clean using oil-free compressed air. The pavement shall be dry prior to application of repair. If emergency repairs are required to wet pavement, the repair location shall be thoroughly dried using hot air. Repairs shall not be performed during periods of rain.
The edges of spalls larger than 1 sq. ft shall saw-cut to a minimum depth of 3/4 in. and the concrete shall be chipped to produce a vertical or undercut edge. Care shall be taken not to cut reinforcing steel.3.3.2 Placement for Spall Repair - Fill the spalls with clean, dust-free, dry aggregate to final grade or 1/2 in. below final grade. Spalls greater than 4 in. in depth shall be filled in lifts not exceeding 3 in. The lifts shall be placed continuously ensuring that the bond interface and spall is completely saturated with resin and that no hardening of the pervious lift occurs prior to placing the subsequent lift. If the resin hardens prior to placing additional lifts the repair will be removed to sound concrete, abrasively blasted and the repair shall be reinstalled. The aggregate size for spall repairs shall be determined based on the depth of the repair as specified in Section 2.3-Aggregate of these Special Provisions. Flood the aggregate completely and squeegee the surface smooth. Immediately add skid resistant sand prior to resin hardening.
3.3.3 Placement for Alligator Cracking Repair - Place dry coarse sand (No.6 to No.14) to grade over the repair area. Spray resin over area until saturated and cracks and spalls have been filled to grade. Immediately broadcast dry skid resistant sand prior to resin hardening. If areas of the cracks are not completely filled, repeat application.
4. PAYMENT
All materials used in the trial overlays, including the substrate base shall become the property of the contractor and shall be removed and disposed of at the contractor's expense.
Rapid setting urethane repairs will be measured by the volume of resin used on the work. The volume to be paid for will be determined by calculations based on the quantity of the resin binder used in the work, exclusive of waste. The contractor shall furnish suitable measuring devices to assure correct proportioning of materials and accurate measurements for pay quantities. The pay quantity shall be the calculated quantity of resin used in the work, exclusive of material used in trial overlays and any wasted or unused material.
The contract price paid per gallon of resin shall include full compensation for furnishing all labor, materials, tools, equipment, and incidentals and for doing all the work involved in furnishing resin, including the rapid setting urethane resin binder, promoter/initiator/or accelerators, and aggregate, as shown on the plans, as specified in standard specifications and these special provisions, and as directed by the engineer.Note: If repairing portland cement concrete surfaces delete Section 3.3.
Note: If repairing asphaltic concrete surfaces delete Section 3.2.
The Preceding Rapid Set Repair Specification Was Developed By Paul Krauss, P.E., of Wiss, Janney, Elstner For Use On Federal, State, County And City Public Works Projects. The Specification covers both Portland Concrete And Asphalt Concrete Repairs.
IMPORTANT NOTICE:
Recommendations for product use are based on tests believed to be reliable. Field conditions vary widely. For this reason, the user must determine product suitability for the particular use and specific method(s) of application. THE FOLLOWING IS MADE IN LIEU OF ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Sellers and manufacturers only obligation shall be to replace such quantity of the product proved to be defective. NEITHER SELLER NOR MANUFACTURER SHALL BE LIABLE FOR LOSS OR DAMAGE, DIRECT, INCIDENTAL OR CONSEQUENTIAL, REGARDLESS OF THE LEGAL THEORY ASSERTED, INCLUDING NEGLIGENCE AND/OR STRICT LIABILITY. The foregoing may be altered only by an agreement signed by officers of seller and manufacturer.
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