RESEARCH AND APPLICATION OF MODIFIED POLYPROPYLENE (PP) MACRO FIBER REINFORCED CONCRETE

The modified polypropylene (PP) macro fiber with diameter of 0.5 mm and length of 38 mm was used in ready mixed concrete, the strength and durability of this concrete with fiber content of 1, 3, 5 kg/m(3) were investigated. The results showed that the use of modified PP macro fiber has little contribution to compressive strength and flexural strength of concrete but a great influence on splitting tensile strength. The splitting tensile strength increased with increasing fiber content. In addition, this kind of fiber can decrease the autogeneous shrinkage of concrete significantly and increase the cracking resistance of concrete. Because of its good insulating property and strong interface with cement paste, the modified PP macro fiber reinforced does not reduce the chloride-penetration resistance of concrete and can effectively prevent the steel bar in concrete from rusting. Finally, the modified PP macro fiber reinforced concrete was applied successfully in an engineering environmental climate laboratory.