Replacing Reinforcing Steel Bars of Continuous Self-Compacting Concrete Slabs with Steel Fibers at Intermediate Support

Abstract

In this paper, the use of  steel fibers instead of the reinforcement steel bars in the continuous self compacted concrete slab panel was experimentally investigated. Tests were carried out on three two-span slab panels under mid span point loads and simply supported at the panels end. The first slab was reinforced by steel bars to resist the negative moments near the internal  supports while the other two slab panels were reinforced by steel fibers only of  percentage of volume fraction (0.5and 1.0) in this zone, without negative steel bars. The load-deflection relationship for the tested slab spans is determined, the first crack load, failure load and deflections were recorded. Also a comparison between the results obtained from this study and that obtained from other study of two continuous slabs made of normal strength concrete (CC) was made , one of these slabs was reinforced by steel bars near the interior supports and the other is reinforced by steel fibers of (1%) in this zone. The test results show that the use of steel fibers instead of the steel bars in the negative moment zone with steel fiber ratio of (VF=1%)  increases the ultimate strength by (39%) and small deflection values at the first loading up to (15kN) while if the steel fiber ratio (VF =0.5%) increases the ultimate capacity by (11.7%) The comparison between the SCC slabs and corresponding CC slabs shows a similar load-deflection curve but the ultimate strength capacity for the SCC slabs with steel fiber gives ultimate strength larger than CC  slabs with steel fibers, while the SCC slabs reinforced by steel bars which show an important effect on the first cracking loading in comparison with CC slabs.