Grouting under a retail building floor

A build-out contractor discovered voids up to 16 inches deep under the floor of a retail location under renovation.  Concrete Jack injected 20 cubic yards of lightweight cellular concrete into the void, which stretched the 120' length of the side wall of the space, through six 1 5/8" holes over five hours.  Renovation activities were not disrupted, and the build-out continued on schedule.  Lightweight cellular concrete that was placed traveled up to 20 feet from the injection points to fill voids under the floor and stabilize it against movement from dynamic loading and future settlement.

Grouting under a freezer floor

Concrete Jack recently used lightweight cellular concrete to void fill under the foam and stainless steel floor of a built-in hospital freezer. The freezer was installed over a depressed area the in the floor and was supported by lathe strips, which caused the floor panels to deflect and deteriorate. Concrete Jack pumped lightweight cellular concrete more than 200 feet through interior hallways and food storage areas and then injected the material under the floor.  This solution saved thousands of dollars of lost productivity that would have accompanied a floor replacement or other repair.  The entire injection process lasted less than four hours from start to finish, and while the crew was finishing up placing material under the panels, the freezer installation contractor was able to start installing the top layer of steel.  The freezer was turned on immediately and refilled as soon as it reached the correct temperature.

Because lightweight cellular concrete does not segregate during pumping (it is a neat mixture of only water and Portland cement along with the foaming agent), the owner of the freezer and the freezer installation contractor were both totally confident that Concrete Jack’s value-engineered solution was the best and most permanent.

Annular space grouting

Concrete Jack's most recent project was installing 228 cubic yards of 40 PCF lightweight cellular concrete for annular space grouting of two sections of 48" welded HDPE sewer force main in Richmond, Virginia.  There were two locations on the job; one that was bored under a large interstate gas line and another where the force main was installed inside of a 60" RCP jacket pipe.

Injecting the lightweight cellular concrete into the annular space between the sewer line and the RCP jacket pipe.

The work area was up to 3/4 of a mile from the nearest roadway, and included pumping material over a temporary stream crossing.  The area in general is considered a swamp, so the ability to pump a long way without material segregation was critical.