CONCRETE PRESSURE GROUTING

What is Pressure Grouting?

Pressure grouting is the process of injecting specialised materials into otherwise inaccessible but interconnected pore or void spaces. This technique involves the high-pressure injection of a grout material – ranging from cement grout to advanced chemical grouts – which flows, gels, or hardens to fill voids, stabilise soils, and create a strengthened or impermeable grouted mass.
The grout is injected under pressure at strategic locations to repair and strengthen soil, rock, and concrete structures. It is a readily adaptable process used to improve structural connections, stop water flow, and enhance the ground’s load-bearing capacity.

Compaction Grouting:

This method is designed to improve soil stability in loose soils and is ideal for treating settlements under existing foundations. A very stiff, low-mobility grout is injected at high-pressure to create bulbs of grouted material. This displaces and densifies the surrounding soil through compaction, significantly increasing its load-bearing capacity and preventing settlement.

Jet Grouting:

Jet grouting is a versatile, high-pressure grouting technique that uses a high-velocity jet of grout (often combined with air and water) to erode, mix, and replace the in-situ soil. This process creates “soil-cement” columns or panels (a grouted mass) with known engineering properties. It is used across a wide variety of soil types to underpin foundations, provide excavation support, or create groundwater cut-off barriers.

Permeation Grouting:

Permeation grouting involves injecting low-viscosity grout materials (like microfine cement or chemical grouts) into the soils at controlled grout pressures. The grout fills the pore spaces between soil particles without disturbing the soil structure. This process is ideal for creating barriers to reduce water flow, achieve reduced permeability, or bind granular soils together for increased strength.

Cement Grouting (Cementitious Grouting):

As the most traditional method, cement grouting involves the injection of a cement-based grout material. It is an especially cost-effective method of filling voids of undetermined volumes to provide structure and stability to otherwise unstable ground and structures. It is also extremely effective at stemming or stopping water flow.

Soil Stabilisation & Ground Improvement:

We use pressure grouting to improve poor ground conditions. This geotechnical engineering solution can stabilise soils and enhance the load-bearing capacity of the ground to support new construction or existing structures.

Waterproofing & Sealing Cracks:

Similar to our curtain injection service, our chemical grouting and permeation grouting solutions are highly effective for waterproofing. We can stop active leaks and reduce water flow into basements, tunnels, dams, and below-grade concrete structures by sealing fissures and creating impermeable barriers within the soil or concrete structure itself.

Underpin Foundations & Settlement Repair:

Grouting is a primary method used to underpin foundations and repair damage from settlement. By injecting grout beneath existing foundations, we can fill voids, densify the underlying soil, and in some cases, lift the structure back to level, preventing settlement from causing further damage.

Void Filling (Concrete Pressure Grouting): :

Over time, voids can form under concrete slabs or behind retaining walls due to soil erosion or compaction. Concrete pressure grouting is used to fill voids, re-establish support, and stabilise the structure, often with minimal disruption to normal facility operations.

The Confirma Grouting Process

1. On-Site Assessment

Every project begins with a thorough analysis of the structure and site conditions. We review existing geotechnical reports to understand the soil types and ground conditions. Our team conducts site inspections to locate voids or cracks and determines the practical requirements for the remediation, whether addressing water ingress or soil stability issues.

2. Solution Design

Based on the assessment, we develop a tailored methodology. We work in conjunction with the project’s geotechnical engineering consultants to verify the technical approach. We select the optimal grouting methods, the correct grout material (e.g., cement, polyurethane grout, or other chemical grouts), and map out the strategic locations for injection to meet the design specifications.

3. Precision Injection

Our experienced technicians ensure the grouting process is carried out with precision. The grout is injected at the optimal pressure level with the correct grout volumes. We monitor the injection pressure and flow in real-time to ensure the grout fills the target zones and achieves the required compaction or permeation as specified.

4. Validation and Reporting

Upon completion, we assist in validating the results to ensure optimal results have been achieved. We provide comprehensive Quality Assurance (QA) data that allows engineers to verify reduced permeability or confirm increased strength and stability, providing you with a complete report and peace of mind.