Polypropylene(PP) fiber was modified by acrylic acid grafted on its surface by suspension in water medium.The effect of modified PP fiber on mechanical properties of cement mortar was studied.The surface microstructure and active functional group of modified PP fiber,the fracture profile of cement mortar samples were analyzed by SEM and IR.The results show that acrylic acid is grafted on the surface of PP fiber after modification.Comparing with cement mortar reinforced by ordinary PP fiber,the flexural stre...