LAYING THE GROUNDWORK The first applications of SFRC for free-spanning, loadbearing structures dates back to the early 1990s, when a full-scale test of SFRC concrete was organized in Ternat, Belgium.1 The 160 mm (6.3 in.) thick test slab contained 45 kg/m3 (76 lb/yd3) of Twincone fibers-a straight 1 mm (0.04 in.) diameter, 54 mm (2 in.) long steel fiber with conical ends and a tensile strength of 1100 MPa (160 ksi). STARTING AT GROUND LEVEL When Prologis, a worldwide industrial real estate company, wanted to build their new leased warehouse for car parts near the Volvo factory in Gothenburg, Sweden, they found a site that was ideal except for a thick layer of clay.