Experimental Investigation of Statically Indeterminate SFRC Shallow Beams

The application of FRC in slabs supported on columns or piles has shown technical and economic benefits that can be obtained by combining properly fibre reinforcement mechanisms to those provided by conventional reinforcement placed, as a strip, in the alignment of columns/piles. Therefore, to investigate the influence of steel fibre reinforcement for the serviceability and ultimate limit design state conditions (SLS and ULS, respectively) of statically indeterminate shallow structures that includes conventional steel reinforcement (herein abbreviated by HSFRC), representing a region in the alignment of the columns/piles of an R/FRC slab, six continuous shallow beams of 400 × 125 mm2 cross section, and 6500 mm of length (two equal continuous spans of 3000 mm each) were experimentally tested. The variables investigated in this experimental program considered the fibre content and the conventional flexural reinforcement ratio. The results show that in ULS conditions, the HSFRC shallow beams performed better than conventional RC shallow beams in terms of load carrying capacity, providing warnings of imminent collapse and stable post-peak responses. At SLS conditions, the HSFRC shallow beams presented an average crack width and spacing up to 50 and 48% lower than their counterparts in conventional RC.