In January 2014, a GCCM was used as a remediation solution for a section of concrete channel adjacent to Cunningham Highway in Aratula, Queensland.

The channel had suffered erosion and damage, which was impairing its ability to collect and discharge water run-off from a hillside adjacent to the highway. This had the potential to cause issues with flooding and damage due to the washout of fines, as the channel was often exposed to high flow rates during wet weather. Shotcrete had been considered for the project, but the associated rebound risked damaging existing road infrastructure, whilst the equipment required for such an installation would have an impact on vehicular traffic utilising the highway. There was also limited access to the installation site due to the placement of roadside barriers.

Prior to installation the site was cleared of vegetation and debris, and several cuts were made into the existing channel to allow the product to be fixed with grout at the top end of the water flow. the products were then delivered to site and unrolled into the channel using a crane truck and spreader beam. The product was cut to length and fixed in place using ground anchors and concrete screws. Adjacent layers were fixed together using stainless steel screws and Sika adhesive. The interface between product and the cuts in the channel made during preparation were filled with a non-ferrous, non-shrink grout, which ensured no undermining of the material during heavy water surges. The product was then hydrated using a water truck and spraying equipment. A series of channels using a total of 250sqm were able to be completed in four days by an installation team of 5.

The installation was very successful, allowing the remediation work to be completed rapidly in average temperatures of 28°C with very low impact on the vehicular traffic utilising the highway.

CONTRACTORS: McIlwain Civil, Hydrovac Excavations