SECTION 534: EPOXY INJECTION
534.1 Description
This Work consists of rebonding cr acks or delaminations in exis ting concrete using an epoxy adhesive injection system.
534.2 Material
534.2.1 General
The Contractor shall use non-shrink epoxy Materials, 100% solid , two-component, moisture-insensitive adhesives i n accordance with Table 534.2.1 :1, “Epoxy Injection Material Requirements.” Table 534.2.1:1 Epoxy Injection Material Requirements Requirements Property Test Type I Type II Slant shear strength, minimuma AASHTO T 237 3,000 psi 3,000 psi Set time @ 77 °F, maximum AASHTO T 237 18 h b Pot life @ 77 °F, minimum AASHTO T 237 10 min 60 min Viscosity @ 77 °F ± 3 °F (poises)c ASTM D 2196 2.5–9.0 90 ± 20 Specific gravity @ 77 °F — 1.1 1.1 Tensile strength, minimum ASTM D 638 4,000 psi 4,000 psi Compressive strength, Minimum ASTM D 695 6,000 psi 6,000 psi aIf bonded to saturated surface dry samples, cure for seven (7) Days at 40 °F and 90 to 100% relative humidity. The Department will use a joint width of 3/ 16 inch for Type I, and 3/8 inch for Type II for testing purposes. bAdhere to the manufacturer’s spec ified set time for constructio n purposes on these wider cracks. cBrookfield #3 spindle, 60 RPM af ter mixing at slow speed for th ree (3) min. The Contractor shall use Type I epoxy Material for cracks less than 1/4 inches wide. The Contractor shall use Type II epoxy Material for cracks 1/4 inch wide or wider. The Contractor shall obtain Department approval of epoxy Materials before use. If the product provides unsatisfactory results, the Department may rescind the approval .
534.2.2 Product Data and Packaging
The Contractor shall label each container with the following: 1. Product name; 2. Component designation, “A” and “B;” 3. Manufacturer’s name; 4. Batch number; 5. Ratio of component mixture; 6. Complete instructions for storing, mixing, and using; and 7. Safety requirements. The Contractor shall package components in separate containers.
534.2.3 Test Reports
The Contractor shall provide Certified Test Results (CTR) for e ach batch of the epoxy system, verifying that the mixed epoxy is in accordance with Ta ble 534.2.1:1, “Epoxy Injection Material Requirements.”
534.2.4 Injection Port Materials
Injection ports are tubes, fittings, pressure plates, or other devices used as entry points for the epoxy adhesive. The Contractor shall use suitable meth ods to seal each port after injecting epoxy at that port.
534.2.5 Temporary Surface Sealant
The Contractor shall use a temporary surface sealant to retain the injected epoxy adhesive. The Department will also allow pressure plates or ot her methods for retaining the epoxy adhesive.
534.3 Construction Requirements
534.3.1 General
The Contractor shall perform the epoxy injection process in acc ordance with the manufacturer’s recommendations. The Department will mark cracks and delaminated areas for injec tion. The Contractor shall inject epoxy when concrete temperature is between 50 °F and 80 °F. The Contractor shall inject epoxy continuously over the entire crack or area of delamination. The Contractor shall maintain low pumping pressu res to prevent lifting the delamination.
534.3.1 1 Epoxy Sampling During Operations
Before starting injection Work, at hourly intervals during cont inuous injection Work, and when requested by the Project Manager, the Contractor shall tak e a three (3)-fluid-ounce sample of mixed epoxy from the injection device. If the sample indicates improper proportioning or mixing of the epoxy, the Project Manager will suspend injection Work until the Contractor corrects the problem.
534.3.1 2 Core Sampling
At the Project Manager’s discretion, the Contractor shall take core samples from injected cracks and delaminated areas and submit them to the Project Man ager to verify penetration and bonding adequacy. The Contractor shall core with a diamete r of 1 1/2 inch and to the full crack depth or six (6) inches , whichever is smaller. If required, the Project Manager will specify core sample locat ions. The Contractor shall submit at least one (1) core sample for every 50 ft of injected crack or every 50 ft 2 of injected delamination. The Contractor shall fill core holes with a Depa rtment-approved epoxy mortar.
534.3.2 Equipment
The Contractor shall use positiv e displacing dispensing Equipme nt that is capable of injecting epoxy at set pressures without pressure build-up. Where the Contractor uses pressure plates to seal cracks, the C ontractor shall use a special pressure fitting on the in jection device to prevent lea kage. If the Contractor drills out injec tion ports, the Contractor sh all use drilling Equipment with a vacuum system to remove and not compact drilling dust into cr acks or delaminations.
534.3.3 Crack Injection
534.3.3 1 Crack Preparation
The Contractor shall clean surface openings and crack interiors with oil-free compressed air to remove dirt, dust, silt, and other Materials. If the De partment determines the result is inadequate, the Contractor shall use another cleaning method su ch as vacuuming, pressure flushing, routing, or sawing. If using pressure flushing, the Contractor shall blow water out with oil-free compressed air.
534.3.3 2 Injection Ports
Unless the Project Manager approves other methods, the Contract or shall drill holes along the crack to insert the injection ports.
534.3.3 3 Temporary Crack Sealing
The Contractor shall temporarily seal surface openings of crack s between injection ports with material that can retain the epoxy adhesive during pressur e injection and until the epoxy hardens.
534.3.3 4 Crack Injection Process
When Material travel is indicated, the nozzle shall be moved to the port that shows epoxy, and the pumped port sealed and this method continued unt il the crack is completely filled. Where vertical and horizontal cracks intersect, the Co ntractor shall inject the vertical crack below the intersection first. On wide cracks, where epox y movement between ports will be rapid, the Contractor may pump two (2) or more ports simulta neously.
534.3.4 Re-bonding Delaminated Areas by Epoxy Injection
534.3.4 1 Injection Ports
The Contractor shall use at l east one (1) port for every square yard of delaminated areas.
534.3.4 2 Temporary Sealing of Delaminated Openings
The Contractor shall temporarily seal the surface openings of c racks in the delaminated areas to prevent leakage of epoxy Material.
534.3.4 3 Delamination Injection Process
The Contractor shall begin injection at one port near the perim eter of the delaminated area and continue until there is epoxy at an adjacent port. Th e Contractor shall then plug the port being pumped and continue the injection at the adjacent po rt showing epoxy. The Section 534: Epoxy Injection Page 458 Contractor shall continue this process until the entire delamin ated area has been injected. The Contractor may pump two (2) or more ports simultaneously.
534.3.5 Finishing Operations
After curing is complete, the Contractor shall remove excess se aling material from the concrete surface without altering the concrete surface color or texture.
534.3.6 Loading Restrictions
The Contractor shall not allow traffic and other loads on the i njected Structures until the epoxy adhesive is solid.
534.4 Method of Measurement
The Department will verify the measured quantities with the Con tractor daily.
534.5 Basis of Payment
Pay Item Pay Unit Epoxy Injection Type Gallon
534.5.1 Work Included In Payment
The Department will consider as included in the payment for th e pay item(s) listed in this section and will not measure or pay separately for the followin g Work: 1. Surface and crack preparation. 2. Coring, if required. Section 535: Crack Sealing Using Low-Viscosity, Gravity-Fed Sea lers Page 459