SEALING/CLEANING INTERIOR OR EXTERIOR SURFACES
If the crack is contaminated on the outside it is necessary to remove this contamination from the surface of the crack so that it can be located exactly. If it is a wide crack with high waterflow it may be necessary to seal the surface of the crack with a surface sealing material.
If there is the possibility of the interior surfaces of the crack being contaminated it is necessary to flush out the crack with 5% Phosphoric Acid, followed by flushing with water. Don't use high concentrations of acid as it can create a chaulk in the crack.
INJECTION HOLES AND PACKERS
Holes should be drilled straight into the crack down to 2/3 the thickness of the concrete or at an angle of 45 degrees to the surface with your target being 1/2 the thickness of the concrete structure. The size of the hole is determined by the size of the injection packer being used. The most common size is 3/8 in. in Canada for use with the 3/8" Plastic Hammer-In Packer. The depth of the hole is approximately 1/2 the thickness of the concrete. The same measurement can be used to determine the drilling distance from the crack. The injection packers can be spaced from 6 in to 3 ft. apart depending on the size of the crack, place the packers into the hole and hammer firmly into place, the long zerk is then installed using a 5/16 in. nut driver
Two pumps, one for water and one for grout are suggested. It is always recommended that the crack be flushed with water. The flushing of the crack is highly recommended. This procedure will remove debris and drill dust, plus it will tell you if you have intersected the crack, and how it will behave during grout injection.
INJECTING CHEMICAL GROUTS.
Always flush your pumping equipment with Leak-Proof PUMP CLEANER prior to injecting chemical grout. Mix the predetermined accelerator dosage with the chemical grout. For single component polyurethane grouts, no reaction will occur until the grout with accelerator comes into contact with water.
It is advisable to begin your injection at the lowest packer on a vertical crack, or at the first packer flushed for a horizontal crack. During injection you will notice that the water is displaced from the crack by the grout. Continue injecting until the chemical grout appears at the adjacent packer. Disconnect and start injecting at that adjacent packer. After injecting a few packers, come back to the first packer and inject all the packers for a second time. Some of the packers will take more grout, which will help densify the grout in the crack. Injection pressure can vary from 100 PSI to 2500 PSI depending on the width of the crack, thickness and condition of the concrete.
When the crack has been injected we recommend that you re-inject a small quantity of water into each packer, this will cure the grout resin left behind in the drill holes. After injection, and after the chemical grout has completely cured (approx. 1-7 days) the injection packers can be cut off flush or below the concrete surface. The cured grout which will bond tenaciously with concrete surfaces can be removed with a wire brush, scrapers or hand held grinder.
These recommendations are based on tests believed to be reliable. Since field conditions vary widely the user must determine the suitability of the product for the particular use and method of application.
Johnson Group Online
(1569373 Ontario Ltd.)
17 McConkey Place, Barrie, Ontario, Canada L4N 6H1
Office (705) 728-3476, Fax (705)-728-3305