Fabric formwork is almost always filled with plain concrete, with a maximum aggregate size most commonly between 4mm and 10mm depending on the application. Reinforcement can be incorporated but it can have a detrimental effect on reliability of placement and concrete durability.
The characteristics of fabric formwork create high quality concrete with high surface abrasion resistance. It achieves this as the density of the cement paste forces free water and air in the mix out through the fabric leaving behind a dense matrix of sand and cement particles.
For the concrete to pump well, flow sufficiently and fully fill the fabric, a high water:cement ratio of 0.55 is commonly used. Our standard mix, combined with fabric formwork and our installation guidance makes it nearly impossible to have honeycombing, entrapped water voids or washout of cement fines, all of which can be common durability issues with marine concrete. Our standard mix meets the requirements of EC2 and BS6349 for a plain concrete design life of over 50 -100 years.
We specialise in developing construction solutions using fabric formwork and in situ concrete where traditional construction methods are impractical or unreliable.
Over 50 years we have developed working methods with fabric formworks for construction underwater or where access is impractical. Due to the nature of fabric formwork, once filling starts it must be completed to achieve the required result. Our concept solutions and construction engineering ensure constructability and risk mitigation and output clear instruction to the installation team, supported by our on-site engineer training and support.