523.01 Concrete Surface Repair By Sealing
522 SECTION 523
523.01 Description
A.General This work consists of sealing bridge decks and approach slabs and filling and rebonding cracks.
B.Definitions Acrylic Resins. Thermoplastics, thermosetting polymers, copolymers of acrylic acid, methacrylic acid, esters of these acids, or acrylonitrile, used to produce synthetic rubbers and lightwe ight plastics. Density. Mass per unit volume of a material. Bulk Cure. Time required for the methacrylate monomer to harden and form a polymer. Epoxy Penetrant. A low viscosity, two component, epoxy -resin bonding system for application to Portland -cement concrete. Flash Point. Lowest temperature at which a material gives off explosive or ignitable vapors. High Molecular Weight Methacrylate (HMWM). Non -fuming monomer with a low viscosity, low volatility, low initial shrinkage, and high flash point. Member of the acrylic family of monomers and polymers. Initiators. Chemicals that start polymerization. Monomers. Liquid molecules that a catalyst reaction converts into solid polymers. Promoters. Chemicals used with initiators to accelerate polymerization. Resin . Natural or synthetic, solid or semi -solid organic material of indefinite and often high molecular weight, with the tendency to flow under stress. Shelf Life. Maximum interval during which a material may be stored and remain in a usable and safe condition . Surface Cure. Amount of time required after placement before the HMWM treated concrete is without surface liquid or tackiness. Vapor Pressure. Component of atmospheric pressure caused by vapor; expressed in inches, centimeters, or millimeters of height o f a column of mercury. Measures the volatility and depletion rate of monomers. Viscosity. Resistance to flow by gases or liquids subjected to shear stress. Working Time. Elapsed time after mixing methacrylate monomer with catalyst before solution viscosit y increases. Depends on the temperature and the amount of initiators and promoters used. Varies with the manufacturer’s monomer system. CONCRETE SURFACE REPAIR BY SEALING 523.02 523 523.02 MATERIALS The Department will allow the use of either HMWM or epoxy resin to seal the cracks.
A.Materials for HMWM
1.Monomer Materials Provide HMWM with low volatility, which does not evaporate in accordance with Subsection 701.13(B)(10), “Type K — Monomer Materials for HMWM.”
2.Storage of HMWM Materials Store initiators and promoters separately to prevent a violent reaction or explosion. Before shipping, obtain a material safety data sheet (SDS) for each material with information about the following: Safe practices for storage, Handling and disposal, Explosive and combustion characteristics, Health hazards, and The manufacturer’s recommended firefighting techniques. Post Safety Data Sheets (SDS) and handling information at storage areas and at the job site. Provide a copy to the Engineer.
a.Monomers Store m onomers in shaded areas away from the initiator storage area. Provide storage areas ventilated to prevent the hazardous buildup of vapors.
b.Initiators Store initiators in temperatures 90 °F [32 °C] or less, and away from the monomer and promoter storage areas.
c.Promoters Store promoters in temperatures 90 °F [32 °C] or less, and away from the initiator storage area.
3.Safety Provisions for HMWM Train personnel to safely handle materials in accordance with the manufacturer’s recommendations. Wear impervious protective gloves and splash -proof goggles while applying the HMWM. When handling solvent for cleaning and flushing, minimize personal and environmental hazards as the Engineer approves. Provide an eye wash facility and a soap and water w ash station at the job site. Inform workmen of the following: HMWM monomer will soften gum rubber soled shoes, and Clothing or leather saturated with the HMWM monomer will harden and become brittle.
523.04 Concrete Surfa Ce Repair By Sealing
524 B. Materials for Epoxy Resin Provide epoxy resin in acco rdance with Subsection 701.13(B)(11), “Type L – Materials for Epoxy -Resin.”
C.Fine Aggregate (Sand) for HMWM, Epoxy Penetrants, or Both Provide sand with a maximum moisture content of one -half of the percent absor ption of the aggregate. Provide sand free of dirt and other organic materials, and in accordance with the gradations in Table 523:1. Table 523:1 Fine Aggregate Gradations Sieve Size Percent Retained Maximum No. 4 [4.75 mm] 0 – 1 No. 8 [2.36 mm] 0 – 10 No. 30 [600 µm] 0 – 95 No. 50 [300 µm] 0 – 100 The gradations in Table 523:1 allow commercially available blast sands of No. 8/20 (2.36 mm/850 µm) or No. 10/20 (2 mm/850 µm). The Engineer may approve alternate gradations.
523.03 Equipment — Vacant
523.04 Construction Methods
A.General Submit to the Engineer a work plan including surface preparation techniques, materials, and the installation procedures. Ensure a technical representative from the manufacturer is on the site for a minimum of one full day during the flood coat application or provide a written certification from the manufacturer stating that the contractor is qualified to apply the sealer for the flood coat. Written certification from the manufacturer must be dated with the last 12 mon ths and the workers with the certification must be present. Cure new concrete for at least 28 days before applying sealers. Allow quick set concrete patches to cure for at least 48 hr before abrasive -blasting. For cracks or joints that extend to the bott om of the bridge deck, seal the bottom of the deck. The Department will not allow the use of sealers for patching decks. Place sealers in good weather (when rain or falling temperatures are not forecast) and when traffic can be diverted for the manufactu rer recommended curing time.
B.Surface Preparation - HMWM, Epoxy Penetrant, or Both Abrasively blast and remove traces of asphalt or petroleum, excess grout, and concrete curing agents. Ensure dry surfaces before applying sealers. Allow the surface to dry for at least 48 hr after rain. Clean surfaces and cracks using compressed, dry, and oil -free air with an air pressure of at least 90 psi [620 kPa]. CONCRETE SURFACE REPAIR BY SEALING 523.06 525 C. Application of HMWM, Epoxy Penetrant, or Both Apply sealers to clean, dry surfaces when the surface temperature reaches from 45 °F to 90 °F [7 °C to 32 °C]. Place the sealers and mix components in accordance with the manufacturer’s recommendations or as directed by the Engineer. To initiate polymerization, catalyze the HMWM monomers with a metallic dri er and peroxide. To improve skid resistance, broadcast sand into the sealer by hand, or with a machine, before the sealer hardens on the treated area. Apply the sand at a uniform coverage rate from 0.55 lb/yd² to 0.65 lb/yd² [298.5 g/m² to 352.5 g/m²]. F or HMWM, place the sand as the monomer begins to gel. Resume traffic when the Engineer determines the surface is tack -free and the sand resists brushing by foot. Before placing traffic on treated sections and for a minimum of 30 days after application, remove excess sand in a manner approved by the Engineer unless otherw ise specified by the Contract. The Department will allow a slight oil to remain on the surface for several hours.
D.Sealing Individual Cracks Seal cracks by placing sealer in the surface c racks and not on the entire deck. Use a crack comparator aid to visually determine crack size. Unless otherwise directed by the Engineer or technical representative, use sand to fill cracks wider than 1/16 in [1.50 mm] before placing the sealer. If necessary, apply sealer several times to fill the crack.
E.Flood Coats Applied to the Entire Deck Sweep, squeegee, pour, or spray the area so the sealers can flow into the cracks. After the sealer fills the cracks, sweep excess from tining before the material begins to gel. Ensure sealer does not plug the tined surface of the bridge deck.
523.05 Method of Measuremen T
The Engineer will measure along chords 3 ft [0.9 m] long and will include crack repairs with in 6 in [152 mm] of the chord. The Engineer will not measure gallons of sealant resin for flood coats.
523.06 Basis of Payment
The Department will pay for each pay item at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit:
A.SEALER CRACK PREPARATION Linear Foot [Meter]
B.SEALER RESIN Gallon [Liter]
C.DECK AREA SEALED (FLOOD COATS) Square Yard [Square Meter]
535.03 Surface Applied Penetrating Corrosion Inhibitors
526 SECTION 535 SURFACE APPLIED PENETRATING CORROSION INHIBITORS
535.01 Description
This work consists of treating concrete surfaces with a penetrating corrosion inhibitor. The corrosion inhibitor is intended to treat reinforcing steel 1 to 3 in [25 to 75 mm] beneath concrete surfaces which have been contaminated with chlorides and may not be exposed at the time of treating.
535.02 Materials
Provide surface applied corrosion inhibitors that are organofunctional silane based. Use corrosion inhibitors that a re designed to work on both anodic and cathodic areas. Use surface applied corrosion inhibitors on the Materials Engineer’s list of approved products. Provide test data showing satisfactory test results from an approved independent testing laboratory as determined by the Materials Engineer for a surface applied corrosion inhibitor to be considered for inclusion on the list of approved products. Include the manufacturer’s name, test results and dates. Provide test results in accordance with FHWA RD -98-153 test protocol on crack slab black bars subjected to 48 weeks of cyclic salt water ponding. Show a 90% corrosion reduction using this test procedure.
535.03 Equipment
A.General Furnish equipment meeting the requirements of Subsection 108.06, “Methods and Equipment,” and the recommendations of the manufacturer of the corrosion inhibitor. Use spray equipment, brushes or rollers as recommended by the manufacturer.
B.Surface Preparation Equi pment With written approval from the manufacturer, any of the following may be used:
1.Abrasive Blasting Provide compressed air pressure type abrasive blasting equipment of proper size and capacity to clean concrete surfaces as specified.
2.Shot Blasti ng Provide portable type machine designed especially for cleaning horizontal concrete surfaces utilizing recyclable steel shot blast techniques.
3.Hot Water Pressure Washers Provide hot water pressure system for cleaning concrete surfaces as specified, u tilizing 160°F [70°C] minimum water temperature at 3,500 psi [25 MPa] nozzle pressure.
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 536–539 of 935.