In the present study, Nan-Su method has been used for the design of Self-Compacting Concrete (SCC) mix. Producing the SCC actually involves the process of arriving at approximate mix proportion (Nan Su et al., 2001). The Chinese method involves first packing of all aggregates (fine and coarse together), followed by filling of paste in the voids between the aggregates. Here the method is easy and consists of less paste (Hajime and Masahiro, 2003). SCC in its fresh state induces high fluidity, self-compacting ability and high segregation resistance. All these properties lead to prevention of honeycombing in concrete (Vijaykumar and Sakey, 2015). And increase in the cement content will also increase the required water content, which may in turn lead to bleeding and segregation in concrete, and this may lead to use of water reducing agents and superplasticizers (Hajime and Masahiro, 2003). The addition of fibers of length more than 25 mm at the dosage of 0.6% is observed to yield a mix free from blockage during of L-box and U-box tests (Vijaykumar and Sakey, 2015).
Addition of the steel fibers enhances the compressive strength and tensile strength of the concrete. Such addition of the steel fibers imparts the ductile property of the concrete (Steffen and Joost, 2001). And many parameters such as maximum size of the aggregates, volume, type, aspect ratio and geometry of the fibers affect the workability of the SCC (Steffen and Joost, 2001). The objective of this work is to study the effect of different volumetric percentages of steel fibers on the fresh and hardened properties of the SCC with 30% replacement of natural sand by M-sand.