Experimental Investigation on Fresh and Hardened Properties of Hybrid Fibre-Reinforced Self-Compacting Concrete

Abstract

Self-Compacting Concrete (SCC) is a concrete mix having high flowability and resistance to segregation. It fills the framework and consolidates under its own weight without external vibration. SCC has a brittle nature, therefore to improve its tensile properties as well as the behavior under the impact, impregnation of different kinds of fibres can be adopted [1]. Reinforced SCC with polypropylene fibre has shown promisable result in both fresh and hardened state, addition of Hooked end steel fibres along with polypropylene fibre could enhance flexural residual strength, producing a hybrid fibre-reinforced SCC, which is well suited for structural use. Three volume ratios of steel fibres (0.5, 1.0, 1.5%) were mixed with three amounts (0.3, 0.6, 0.9%) of polypropylene fibres. Studies are carried out on the fresh and hardened properties of SCC for all the mixes. The fresh property tests such as Slump flow test, V-Funnel test, U-Box test and L-box test was conducted on the developed SCC to check the compatibility, filling ability, passing ability and segregation resistance. The hardened properties such as compressive strength, split tensile strength, flexural strength was determined by conducting suitable tests as per the European guidelines of SCC (EFNARC) and compared with that of standard specimen. From the experimental test results compressive strength of concretes did not change considerably, but the addition of fibres had noteworthy effects on splitting tensile and flexural strengths. As expected, the increase in fibre content led to an increase in these strengths. Fresh properties of SCC were found to decrease with an increase in fibre content.