Full-Scale Tests of Steel Fibre Reinforced Concrete and Self-stressing Steel Fibre Reinforced Concrete - Overview

Self-stressing steel fibre-reinforced concrete (SFRSSC) is increasingly utilised every day, with its areas of applicability expanding. One such application is ground-level elevated slabs on piles, along with elevated slabs on columns. Although regular steel fibre-reinforced concrete (SFRC) has been previously applied for such cases, albeit somewhat extensively, very few full-scale load-bearing tests have been conducted for these slabs under industrial-level loads up to failure. In Northern Europe, the use of SFRC in ground-level elevated slabs is somewhat common, either with or without additional traditional rebar reinforcement. On the other hand, SFRSSC is still an emerging technology with known benefits, and parts of the technology are yet to be discovered. No calculation method exists to validate the benefits of SFRSSC, specifically the self-stressing impact on load-bearing capacity at the ultimate limit state (ULS) and behaviour under serviceability limit state (SLS) loads. The aim of this presentation is to provide an overview of a comparative full-scale load-bearing capacity test up to failure, comparing two elevated slabs made of regular SFRC and SFRSSC loaded under similar conditions. Material properties were monitored by conducting an extensive battery of laboratory tests. The deformations, cracking, and shrinkage of the full-scale slabs were recorded using both standard sensors and innovative technologies, such as fibre optic sensors embedded in concrete and the digital image correlation method. The slabs were loaded with uniformly distributed sandbags up to the SLS load, and SLS criteria were measured. After unloading, the ULS load was applied; the slabs were evaluated and further loaded up to failure. The test results show that the slab made of SFRSSC had smaller deflections and crack widths, as well as a significantly higher load-bearing capacity.