Effect of the length and the volume fraction of wavy steel fibers on the behavior of self-compacting concrete

AbstarctSelf-compacting concrete (SCC) is a highly workable concrete that fills formwork under its own weight (without any vibration or impact). It also passes easily through small spaces between reinforcement bars. The inclusion of fibers in such concrete limits the concrete shrinkage cracks at early age and enhances some of its properties. However, fibers may affect the flow characteristics of SCC. In this paper, three wavy steel fibers (SF) of different lengths, 35, 40, and 50 +/- 2mm with six different volume fractions (V-f) of 0.3, 0.5, 0.8, 1, 1.2, and 1.4% were used in SCC. The experimental results showed that the addition of SF with higher V-f content and longer length decreases the workability of SCC, reduces its passing ability and increases the possibility of blockage. Mechanical performances of concrete in terms of flexural strength and elasticity modulus were improved, where the slightly compressive strength decreased with an increase in V-f content of SF.