Chemical Grout Work

What is Chemical Grouting?

            Chemical grouting has proven an economic and efficient method of repairing mainline and manhole water infiltration.  The two main categories of chemical grouting are mainline grouting and injection grouting.  Mainline grouting utilizes a packer that is pulled through a pipe with infiltration.  A camera is attached to identify and locate areas of infiltration.  Once an area is located, the packer is positioned and inflated on each end, creating a void around the mid-section of the packer.  A pressure test is administered to confirm a hole or a crack, and then the chemicals are pumped through the mid-section of the packer.  The packer pumps two separate chemicals that, when mixed, react and form a waterproof gel that seals the area of infiltration.  The second type of chemical grouting is injection grouting, in which the chemical reacts with water to form a waterproof seal, and is used to seal areas of infiltration in manholes.  The chemical itself is a mixture of two chemicals, one of which controls the reaction time of the chemical with the water. For strong and fast infiltration, a quicker reaction time is desired to seal the crack before the water pressure can flush the chemicals out of the area of infiltration.  A slower reaction time can be used in weaker leaks to allow the chemical to move farther away before reacting, creating a greater area of sealant.

Our Mainline Grouting

          Over the past couple of years, we have completed a couple of jobs requiring mainline grout repair. One of these jobs was in Rossford.  There were two sections of pipeline requiring repair, and through the use of a TV truck with a packer and camera, we were able to seal multiple leaking pipe joints.  A similar job was completed on Goddard Rd.

Our Injection Grouting

            We have also completed a number of manhole rehabilitation jobs involving grout repair.  In Bowling Green we fixed multiple leaks in 4 separate manholes.  Some of these manholes had infiltration around the joints of the manhole sections and others around the pipes coming into and going out of the manholes.  Another job in Bowling Green created a unique grouting situation: a small pipe going out of the manhole and down and out into a larger pipe had infiltration around joints of the two pipes.  But with the joint being roughly 4 feet from the manhole, an alternative solution had to be developed.  Using a large drill, a hole was drilled through the side of the manhole, and then an inch diameter pipe was pushed through, allowing the grout to reach the joint without reacting with any water in the ground between the joint and the manhole.  At this manhole, the rate that it was leaking was an estimated 52 million gallons of water per year.  In a pump station on 795, a 10 ft diameter pipe with a ¾” stream of water shooting out of the hole was repaired using this technique, and is an excellent example of how strong the chemical can be when used in high-pressure situations.  It was estimated here that the rate of infiltration was 2.5 million gallons of water per year.

Other Grouting Techniques We Use

          There are two methods we use to identify and locate infiltration, but they are methods that can be administered as services themselves, separate from the chemical grouting itself. TV inspection allows one to see the inside of the pipe, and is extremely useful in locating leaks in joints and cracks.  The second method for locating infiltration is dye testing, and this can be useful in discerning whether the water is flow or infiltration, and also can determine where the water is coming from or disappearing to.

            The chemical grouting can also be used to create grout dams in residential homes.  This prevents water from infiltrating a house via the water tap and can reduce excess use of a sump-pump.