MixOnSite has successfully used foam concrete to solve a variety of tunnel backfill grouting challenges. Its unique set of characteristics makes it an ideal choice for either wet or dry tunnels, as well as critical path projects or jobs where access to injection points is limited.


Foam concrete offers several advantages for tunnel backfill grouting applications, including:


  • Mix designs can be customized to project requirements such as void size as well as ground conditions.
  • Lightweight nature of the material will reduce the possibility of pipe floatation or buckling in comparison to heavier conventional grouts and concretes.
  • Flowable and pumpable, these materials ensures complete filling of the tunnel at low pumping pressures that are easily maintained.
  • Energy absorbent and will protect finished tunnels from ground movement.

MixOnSite utilizes state of the art equipment that is capable of batching and pumping foam concrete at rates of over 200 cubic yards per hour at distances of nearly 3 miles. Material density is monitored at the plant and inside the tunnel at the point of injection.