Investigation of Flexural Properties of Cement-Stabilized Macadam Reinforced with Polypropylene Fiber

With low modulus of elasticity, high strength, excellent ductility, excellent durability, and low price, polypropylene fiber is often used in cement-based materials to improve the toughness and anticracking performance of the matrix composite. The aim of this study was to investigate the flexural properties of cement-stabilized macadam reinforced with polypropylene fiber. Four different fiber volume fractions (0.04, 0.06, 0.08, and 0.1%) and four different cement contents (4, 5, 6, and 7%) were used. Besides, a series of tests without mixing fibers was also carried out. By means of four-point loading method, the flexural strength and flexural modulus of elasticity of cement-stabilized macadam were measured. The results indicate that polypropylene fiber can increase the flexural strength and decrease the flexural modulus of elasticity of cement-stabilized macadam. The flexural strength and flexural elastic modulus are increasing with the increase in specimen curing period. When the fiber volume fraction is not beyond 0.1%, the flexural strength is gradually increasing and the flexural modulus of elasticity is gradually decreasing with the increase in fiber volume fraction. Besides, with the increase in cement content, there is a tendency to increase both in the flexural strength and flexural elastic modulus. Furthermore, polypropylene fiber appears to be highly effective in improving the nondeformability of cement-stabilized macadam.