The following is intended to be a general guideline to assist you in the application of our Injection Resins and Gels. Your evaluation of any given application will be necessary to assure successful completion.
1) Surface of cracks to be injected should be cleaned by mechanical means. Grinding, sandblasting or scarifying are acceptable ways of preparing the surface.
2) Injection holes should be drilled with rotary percussion bits. Holes may be drilled directly into the crack or offset and drilled at an angle to intersect the crack. Crack size will dictate hole spacing. For example, small hairline cracks may require a spacing of six inches whereas, a large crack may have spacing of up to three feet. Normally, if reinforcement steel is encountered, the hole or holes will have to be redrilled in such a position that contact with the crack is made.
Cracks tend to veer off in one direction or another below the surface level. For this reason it may be necessary to stagger injection joles from one side of the crack to the other. This will insure that at least half of your holes intersect the crack.
3) Drilled holes should be thoroughly cleaned by either high pressure water or compressed air. High pressure water is preferred since dust or drilling debris could be forced into the crack.
4) Mechanical packers should be used in weak concrete. They should be inserted until the top of the rubber sleeve is flush with concrete. If the rubber is not flush with the concrete it may either spall the concrete when tightened down or blow out when the injection pressures start to rise. Use a 7/16" deep well socket to tighten the packers
Bang in ports are an excellent choice for good concrete. Simply bang them into a 3/8" hole with a hammer.
The tips should be left off of all ports until you are ready to flush the crack
5) Cracks should be flushed to remove dirt, dust or other foreign matter. Flushing can be accomplished by venting the ports and injecting either clean water or oil free compressed air into the crack. It is not advisable to use chemicals unless absolutely necessary. If they are used, it is mandatory that the cracks be thoroughly flushed. Chemicals left in the cracks can result in a less than successful injection project and sometimes a total failure. If water or chemicals are utilized, the crack should be allowed to drain and dry before epoxy injection is attempted.
6) Most cracks will require some type of surface seal to contain the injection resin. A high strength epoxy gel applied neatly with a putty knife is preferable. The gel must be allowed to cure before epoxy injection is attempted. Small hairline cracks may not require a surface seal since epoxy will remain in crack after pressure is relieved. Many times this will assist the injection personnel in observing resin movement through the crack when port to port movement cannot be accomplished.
7) Pump manufacturers generally recommend a ratio check of the pump before injecting resin. We also recommend taking samples of mixed resin at regular intervals while injecting to be sure that the correct ratio of materials is being dispensed. Check for set time and hardness.
8) Normally epoxy injection is started at the bottom of a vertical crack or at either end of a horizontal crack. Ports should be injected in this manner and injection should continue until the crack is full. Many different types of injection pumps are available today. We normally suggest positive displacement units capable of variable pressures and equipped with gages and static mixers.
9) After the injection resin has cured, ports should be removed and holes filled with epoxy gel. Depending upon the final surface desired, the surface seal may be removed with a grinder.
