Challenge
Uneven concrete slabs and subgrade instability on the A14 near Haughley created unsafe carriageway conditions; a rapid, low‑disruption stabilisation was needed to avoid long closures on this key strategic route.
Solution
Geobear injected geopolymer beneath the affected road to fill voids, improve subgrade strength and re‑level the concrete surface rapidly during night‑shift works, restoring stability and serviceability.
Total pavement area treated with geopolymer injection
Drill hole diameter used in injection grid
Night‑shift programme to complete works
A condition survey on the A14 at Haughley revealed settlement and differential movement of concrete carriageway slabs linked to subgrade weakness and traffic loading, resulting in uneven surfaces and potential safety hazards. Highways England had programmed broader reconstruction works in the area as part of its ongoing road improvement scheme, but an engineered ground stabilisation was needed to address specific localized instability efficiently.
The A14 is a major strategic route with heavy daily traffic. Traditional excavation and reconstruction to address subgrade issues and slab settlement would require extended closures, significant cost, and disruption to drivers. A method was required that could strengthen the subgrade, re‑level slabs and maintain traffic flow, delivering robust performance within the narrow windows of overnight working.
Geobear’s approach used high‑density geopolymer injection to stabilise and lift the affected carriageway slabs. A grid of small‑diameter holes was drilled through the concrete surface at regular centres, into which geopolymer was injected to expand and fill voids, compact soils and improve bearing capacity. Laser levelling monitored slab movement in real time to achieve precise re‑levelling targets. The works were executed over night‑shift periods to keep the A14 open for daytime traffic, taking advantage of the rapid strength gain characteristics of the geopolymer material.
Post‑treatment assessments confirmed the pavement was stabilised and re‑levelled within tolerance, meeting safety and performance requirements. The rapid curing geopolymer allowed the road to be reopened to full traffic during daytime hours, avoiding the extensive traffic disruption associated with full reconstruction. By strengthening the subgrade and improving support beneath slabs, the intervention extended pavement performance while integrating with the broader road improvement works on the A14.
Get in touch with our expert team today and discover how Geobear can extend the life of your critical infrastructure assets.
