Sliplines and Annular Space Grouting

Low-density cellular concrete, or grout is used to fill the annular space between an older damaged host pipe and a new plastic liner pipe, usually HDPE. The pipes can be for sewer lines, or culverts under roads or railroads. The grout density is usually kept between 40-55 pcf which is lighter than water so that the water-filled liner will not float. It also needs to be extremely flowable to keep injection pressure to a minimum, around 5 psi and travel long distances (800’) or very small spaces (1-2”) and still achieve 100-500 psi. QC is very critical on every load.