The Residential sector:
Subsidence Ground Stabilisation & Crack Repair
• Initial site survey
• GPR survey to identify problems pre-remediation
• Ground stabilisation by geopolumer resin injection
• GPR survey to validate the ground stabilisation post remediation
• Return & Re-lay existing walkways around the property post remediation
• Cut out cracks in the masonry in preparation for stitching
• Helifix brickwork crack stitching
• Helibar stainless steel strengthening bars
• Helibond bonding resin
• Pointing of brickwork after remediation
The initial site survey undertaken by our in-house technical team revealed potential issues of subsidence highlighted by visual cracks in the brickwork and distortion of the expansion joint. Restek’s GPR survey identified issues common with clay shrinkage and additional ground investigation testing showed that the property was not sat centrally on its foundations.
Restek’s GPR data was conclusive in correlating issues with the property as a direct result of subsidence and showed that the property would require underpinning and crack repair work. Restek designed a value engineered solution involving a non-invasive underpinning solution, using engineered geopolymer resin injections. This innovative method of repair is cleaner, quicker and less intrusive compared to traditional underpinning methods. To compliment our tailored underpinning solution, we proposed Helifix crack stitching, to remediate the cracks in the masonry and to complete the full remediation of the project.
Following client approval, Restek began the project by lifting specific slabs around the property in preparation for installing the resin injection lances. Each lance was precisely positioned based on the engineered test data and tailored design. Restek’s specialist remediation team then injected the specified type and amount of resin into each lance while constantly monitoring the process, using the latest digital monitoring technology.
Upon completion of the underpinning, a GPR survey was undertaken to validate the successful ground stabilisation. The client was provided with a fully detailed report demonstrating the ground prior to injection and also after the ground remediation had been successfully carried out, through 2D and 3D radaragram images which clearly show the success of the remediation.
Once the underpinning phase was complete, we started to remediate the cracks in the brickwork using Helifix crack stitching products, to stabilise the masonry. We installed stainless steel HeliBars, that were bonded into cut slots with HeliBond grout. Helifix is a leading manufacturer of crack stitching products and their products offer quick, effective and permanent solutions to cracked masonry.
Residential ground stabilisation work can often be completed in one to two days and, due to its non-invasive nature, there is usually no need to move out the property before or during the work being carried out. This is entirely dependent on each individual project. Any disturbance of areas around the property during the underpinning process is returned to its original state after any works have been completed, which leaves little to no trace of the work that has been carried out beneath the ground.