Ductal – A High-Performance Material for Resistance to Blasts and Impacts

Abstract

Reactive Powder Concrete (RPC) is a cementitious material consisting of cement, sand, silica fume, silica flour, superplastiser, water and high strength steel fibres. The material, developed by Bouygues the parent company of VSL, is marketed under the brand name of Ductal®. Production in Australia commenced in early 2003. Ductal is almost self placing, has a compressive strength of 160–200 MPa and a flexural strength of 30–40 MPa. In structural applications, Ductal is generally used without any passive reinforcement. Very fine high strength steel fibres are able to withstand secondary tensile stresses. Prestressing counterbalances the main tensile stresses due to bending. The durability properties of Ductal and its resistance to aggressive agents are orders of magnitude better than conventional high performance concrete. A predicted design life in marine environments of several hundred years is achievable. The unique characteristics of Ductal, including exceptionally high energy absorption capacity and resistance to fragmentation, make it ideal for panels and components that need to perform under explosives, impact or shock loads. The flexural toughness is greater than 200 times that of conventional fibre reinforced concrete. In May 2004, the performance of seven Ductal panels was evaluated in two large explosive trials performed at Woomera (South Australia). The panels performed remarkably well, exhibiting high levels of ductility and no signs of fragmentation. In further tests, 100mm thick Ductal blast resistant panels have been shown to effectively resist impacts by blast produced fragments using fragment simulated projectile tests. These panels can also withstand impacts from the highest class of rifle projectiles in the Australian Standard AS 2343. In June 2005, the first Ductal protective panels manufactured to provide resistance to blast were supplied to the Australian Government and installed on an Australian Government building in a high risk international location.