Self-compacting concrete is a pioneering building material; owing to its exceptional properties, it offers several benefits in the construction process. The productivity as well as improved quality of the concrete elements can be achieved by adopting SCC. SCC finds its application in all the circumstances where the above mentioned attributes are mandatory. This is particular true in the case of heavily reinforced concrete members like bridge decks, abutments, tunnel linings and tubing segments, where vibrating the concrete is next to impossible. SCC is equally apt for normal engineering structures (Holschemacher, 2002).
The use of self-consolidating concrete (SCC) is gaining momentum so as to overcome possible defects arising from the use of normal concrete. Such defects can be in the form of honeycombs and voids formed due to congestions created by vertical and horizontal reinforcing bars, preventing concrete to fill the entire form work. The use of SCC, because of its high flowability will alleviate such potential problems (Kanellopoulos, 2020). SCC has its share of disadvantages and shortcomings.
SCC reaches lower values for E-modulus, compressive and flexural strengths but higher values for shrinkage creep and strain under restrained conditions. Besides the paste volume, the cement type plays a fundamental role regarding creep (Leemann, 2014). SCC mixtures show a greater plastic shrinkage as compared to conventional concrete mixtures. The main reason for this phenomenon is their lack of bleeding. Accordingly, SCC is more vulnerable to shrinkage cracking. The vulnerability is especially high during setting (Turcry, 2006). Studies were conducted to study the role of steel fibers in order to reduce such defects in SCC.
Steel fiber-reinforced self -compacting concrete (SFR-SCC) can be used to enhance shrinkage, serviceability aspects which arise due to a low aggregate-cement ratio. Durability, flexural strength and resistance to freezing and thawing are increased in SFR-SCC (Corinaldesi, V., and G. Moriconi, 2004). Self-compacting concrete (SCC) possesses great deformability and segregation resistance, adequate viscosity and lower value of yield stress. Inclusion of steel fibres in combination with mineral admixtures enhances the performance of SCC. Combination of hybrid fibres in SCC improves the flexural strength and durability (Ramkumar, 2020).
Iqbal (2015) conducted investigations to study the effect of change in micro steel fiber content on the properties of steel fiber reinforced high strength lightweight self-compacting concrete (SHLSCC). Alteration of nature of concrete from brittle to ductile is achieved by addition of steel fibers to SCC. Adoption of lightweight concrete leads to reduction in extra loads. Moreover, SCC evades the necessity of vibrators for concrete compaction. This is useful in case of renovation or strengthening of existing structures. They conclude that there is strong influence of steel fiber content at doses of 1% or more on the workability of SHLSCC. Compressive strength reduced by 12%; splitting tensile strength and flexural strength increased by 37% and 110% respectively, when steel fiber content from increased from 0–1.25%.
Pereira (2008) has also established that ductility of SCC can be greatly improved by addition of steel fibers. (Raju, 2020) carried out investigations on SCC beams and concluded that their flexural performance is enhanced with the addition of steel fibers. Similarly, numerous researches have been carried out to establish the effect of steel fibers on various properties of SCC. Only a few investigations have been done to understand the effect of MSF on the resistance of SCC beams against flexure. More studies of this kind are required and flexural strength of MSF-SCC beams need to be established further.