Effect of polypropylene fibre on mechanical and shrinkage properties of cement-stabilised macadam

A parametric experimental study has been conducted to investigate the effect of polypropylene fibre on the mechanical (compressive strength, splitting tensile strength, compressive modulus of resilience, flexural strength, flexural modulus of elasticity) and shrinkage properties (dry and thermal shrinkage coefficients) of cement-stabilised macadam. Four different fibre volume fractions were used: 0.04, 0.06, 0.08 and 0.1%. Tests without mixing fibres were also carried out. The results indicate that the mechanical and shrinkage properties of cement-stabilised macadam can be improved by mixing polypropylene fibre with it. Polypropylene fibre distinctly reinforces the strength of cement-stabilised macadam; however, it can effectively decrease the compressive modulus of resilience, flexural modulus of elasticity and shrinkage coefficients of cement-stabilised macadam. As a result, it increases the resistance to deformation of cement-stabilised macadam. When the fibre volume fraction is not beyond 0.1%, there is a tendency of increase in each strength; however, compressive modulus of resilience, flexural modulus of elasticity and dry and thermal shrinkage coefficients gradually decrease with the increase in fibre volume fraction. Furthermore, polypropylene fibre appears to be highly effective in controlling dry and thermal shrinkage cracking of cement-stabilised macadam.