Auger Drilling Techniques | Percussion Drilling Techniques | OdexTM or TUBEX | Grout Pumps | Grout Sources
Vibratory Drilling Techniques (Crane & Mandrel) | Air Rotary or Rotary Wash | Grout Mixes | Slump Test

Figure 6.  Compaction Grout Pump & truck mixer delivery

Currently, twin cylinder positive displacement piston pumps are the first choice for compaction grouting. This pump ensures a constant delivery volume under varying pressure conditions. The pump should be specifically designed to provide high pressure (1,000 psi, typical (6.9 MPa)) with a constant flow rate which may be varied throughout the construction operation. The grout pump design is significantly different from the typical concrete delivery pump. A concrete pump swing tube or discharge valving typically permits minor leakage of water through the valves. However, where sustained slow delivery volumes and high pressures are required, the water will tend to squeeze out and cause a "sand block" within the pump mechanism. Therefore it is necessary to utilize a specifically designed compaction grout pump which utilizes a "leak free" technology. A compaction grout pump typically has a small cylinder bore (2 to 4 inches (5-10cm)) and a long stroke (40 to 50 inches (100-125 cm)). Most pumps are trailer or skid mounted and powered by a diesel engine. The engine operates a hydraulic motor which powers the grout cylinders. This type of pump is most popular because of the wide range of pumping pressures and placement volumes that can be achieved with a single pump unit.

Figure 6.  Compaction Grout Pump & truck mixer delivery