What is Pressure Grouting?

In a world where cities are crowded and space is limited, contractors are often building up or excavating and going down. With impressive large scale projects popping up everywhere, the ground needs to be stable enough to support the growing concrete jungle and this is where pressure grouting comes in.

Pressure Grouting in a Nutshell

Pressure grouting is a form of injection grouting sometimes referred to as permeation grouting or cement grouting. This process stabilises, strengthens and reduces permeability in the area it is injected. Grout can be cementitious, resinous or  a solution chemical mixture and is ideal to use in awkward spaces and can avoid extensive and expensive ground excavation work. The material is injected into subterranean voids in soils or rocks and will permeate granular soils with flowable grout to therefore create a cemented mass.

What is Pressure Grouting used for?

• As a barrier to groundwater flow
• To fill redundant drains, manholes and sewers 
• To underpin and strengthen foundations
• To provide excavation support
• To provide soil stabilisation
• To infill spaces under machine bases
• To strengthen cavity or rubble walls
• To ensure structural integrity and prevent movement 
• To infill awkward shapes e.g. gaps around pipe inserts
• To infill redundant bridges
• More uses for grout pumps >

How to pressure grout

The process of pressure grouting is of course condition dependent since there are many scenarios pressure grouting is performed in. Sometimes the process needs to take place on an existing structure where the ground has perhaps been affected by the weather e.g. erosion, flooding, water accumulation, poor drainage and on other occasions you may pressure grout when starting from scratch on empty development space. If there are issues with ground stabilisation, always ensure a qualified pressure grouting contractor  assesses this.

When pressure grouting, your selected material (e.g. Portland cement/microfine cement grout) is injected under pressure at planned locations through single ‘port’ or multiple ‘pot’ pipes. It is important to match the grout particle size and void size to allow the grout to permeate. It is also essential to select the right machine for your job, read more on this here >. When grouting, you begin pumping at the lowest elevation, withdraw the pipe slightly and repeat pumping at a higher elevation and continue to level up. Find out more about grout pumps available to complete your project here >