Making Unstable Ground Buildable

Why should the ground need stabilisation?

When ground conditions are poor, the risks can quickly add up.

Loose sands, permeable soils, groundwater movement and liquefaction can all create challenges for construction projects. Whether it is an infrastructure project, a commercial building, or a major civil works package, unstable ground can affect programme timelines, budgets, and long-term performance.

For decades, cement-based grouting has been a common solution. While it can work well in many situations, it can struggle in finer sands and silty soils.

This is why engineers and contractors are looking more closely at alternative ground improvement methods that can deliver more predictable results with less site disruption.

One option gaining attention is colloidal silica permeation grouting.

• FREE DOWNLOAD: CONQOR S70 Technical Data Sheet

Why traditional grouting can be challenging

Traditional permeation grouting relies on injecting cementitious materials into the ground to fill voids and bind soil particles.

The challenge is particle size. Cement particles can be too large to move through some soils effectively. In finer sands and silty soils, grout movement can be restricted, making uniform treatment difficult.

The practical outcome is often a higher number of injection points, greater material consumption and less confidence in the uniformity of treatment. For contractors, that often means greater complexity, longer installation times, and increased cost risk.

How colloidal silica works

Colloidal silica takes a different approach.

Instead of using cement particles, the treatment uses extremely small silica nanoparticles suspended in water. Once injected and activated, the material gradually forms a stable gel throughout the soil.
The particle size allows them to move through soils that conventional grouts often struggle to penetrate.

This helps the treatment spread more evenly throughout the target soil zone, thereby reducing permeability and improving overall ground stability.

Research has shown that colloidal silica treatments can improve soil strength, reduce water movement, and help lower liquefaction risk in suitable ground conditions.

Why engineers are taking notice

One of the recurring challenges with conventional permeation grouting is achieving full treatment in finer soils. This is where colloidal silica can offer different performance.

Because the particles are significantly smaller than cement particles, they can reach areas that traditional grouts may not access. Larger, more consistent treatment zones are often achievable with fewer injection sites.

That translates into better site efficiency and less time spent on injection works. Fewer mobilisation hours, reduced drilling activity, and faster progression through treatment zones.

Another benefit is low-pressure installation.

Some traditional grouting methods can create unwanted ground movement or disturb surrounding soils.
Colloidal silica treatments are typically installed at lower pressures, reducing the risk of soil fracturing and helping protect nearby structures and services.

Predictability is also important. Modern colloidal silica systems can offer adjustable gel times, allowing the treatment to be matched to site conditions and construction schedules.

More than groundwater control

Many ground improvement projects begin with the need to reduce groundwater movement.

However, colloidal silica treatment can provide additional benefits. As the gel develops in the soil, it helps bind particles together and fill voids. Over time, this can improve strength, stiffness, and overall ground performance.

• Liquefaction mitigation
• Groundwater control
• Excavation support
• Foundation improvement
• Piling and anchoring works
• Contaminant containment
• Infrastructure remediation projects

This versatility helps drive wider adoption across geotechnical, civil, and infrastructure sectors.

A practical solution: CONQOR S70

MARKHAM’s CONQOR S70 is a colloidal silica-based soil permeability reducer and stabiliser developed for permeation grouting and ground improvement applications. CONQOR S70 helps project teams significantly reduce soil or sand permeability and increase ground-bearing strength without harming the underlying aquifer.

The two-component system forms a resilient colloidal gel that reduces water movement while improving ground bearing capacity. It can be used for both temporary and permanent ground improvement works, including groundwater control, contaminant isolation, and liquefaction risk reduction.

The system also offers adjustable gel times, allowing contractors to tailor performance to specific on-site conditions.

Importantly, project outcomes can be verified using recognised geotechnical testing methods, including permeability testing, pore pressure monitoring, core sampling, and standard site investigation techniques.

Looking ahead

As projects become more complex and construction sites more constrained, the need for predictable, low-disturbance ground improvement methods continues to grow.

Colloidal silica will not replace every soil stabilisation technique. However, where penetration, groundwater control, and treatment consistency are critical, it offers clear advantages over traditional approaches.

For geotechnical engineers, civil contractors, and ground improvement specialists, the technology provides another tool for solving difficult ground conditions with greater confidence.

In many cases, the difference between a challenging site and a buildable site comes down to choosing the right treatment method.

On sites where conventional grouting struggles to achieve the required penetration, colloidal silica is giving engineers another practical option. In the right ground conditions, that can make the difference between a workable design and an ongoing construction challenge.

Does this resonate with your own site challenges? We would really like to hear from you.