Performance evaluation of polypropylene fibre reinforced recycled aggregate concrete

The present experimental investigation examined the influence of incorporation of microfilament type polypropylene fibres into low strength recycled aggregate concrete on the basis of number of parameters such as compressive strength, split tensile strength, flexural strength, modulus of elasticity and non-destructive parameters. Experimental studies are carried out with addition of 0.5%, 0.75% and 1% polypropylene fibres in both natural aggregate concrete (NAC) and recycled aggregate concrete (RAC). The recycled aggregate concrete is prepared with 100% replacement of recycled coarse aggregates with natural coarse aggregates. The present study reveals that the fibre content has negligible effects on compressive strength. However, the fibres play an important role in determining the split tensile and flexural strength of concrete for both NAC and RAC. The maximum increments for RAC are 12.01% and 17.15% for split and flexural strength values respectively over unreinforced RAC. Based on the results obtained for each series, it can be inferred that optimum fiber content is 0.5%. The variations of axial and lateral strain with axial stress are also determined using strain gauges. It can be observed that the effect of fibres on strain enhancement is more prominent in case of NAC compare to RAC.