Effect of Graded Steel Fibres on Fresh and Hardened Properties of Self Compacting Concrete

Abstract

Research work carried in various parts of the world has established that adding fibres to the concrete improves the hardened properties like strength and ductility of the material but leaving a remark on the decrease in fresh properties of the concrete. Hybridisation of steel fibres with other fibres  like synthetic, natural or glass fibres has shown to be effective in enhancing the energy absorption and fire resistance of concrete. The present study aim to investigate the fresh and hardened properties of graded steel fibre reinforced self compacting concrete. The macro fibres with 0.5mmφ , 0.75mmφ and 1mmφ 60mm length are added individually at 0.25%,0.5%,0.75% and 1% as volume fraction to the concrete. This addition of macro fibre percentage as volume fraction is optimized based on the experiments organized for evaluating the fresh and hardened characteristics of concrete. For the optimized macro fibre percentage 0.5mmφ 30mm length fibres are replaced from 10 to 50% with an increment of 10%. The graded fibre percentage optimized is replaced with micro fibres which are 0.25mmφ 13.5mm length at 10 to 50% at an increment of 10%. It is observed that the addition of different fibres from macro level to micro level has decreased the flow characteristics of self compacting concrete but there is an ideal increase in the strength characteristics of self compacting concrete.