Experimental Study on Physical and Mechanical Performance of the Polypropylene Fiber Reinforced Concrete (Mortar)

The concrete is a kind of building material used at most in the engineering ,and it is also the main construction material. But the concrete has some inherent defects. The improvement of concrete properties is very necessary.The polypropylene(PP) fiber is a new synthetic material for improving the concrete properties.In this article, the effects of PP fiber on the properties of anti-cracking about the cement mortar ,physics, mechanics and anti-frost of concrete was discussed by changing the PP fiber length and the PP fiber weight in unit volume.The regulations of PP fiber reinforced concrete were investigated.1. The characteristics of crack was measured through 7 specimens of PP fiber cement mortar with the size of 600mmx600mmx40mm. In terms of the experimental results ,the influencing regulation of the PP fiber length and the PP fiber weight in unit volume on the early crack time, the crack width and the crack area was analyzed. The mechanism of PP fiber influencing crack was studied.The study results show that PP fiber can postpone the initial crack time and improve the property of cement mortar anti-cracking evidently.2. The basic mechanical index sign such as compressive strength, splitting tensile strength, flexural strength and shear strength of PP fiber concrete was measured through 30 concrete specimens with the size of 100mm×100mm×100mm and 35 concrete specimens with the size of 100mm× 100mm×400mm. In the process of pouring specimens, dense degree of concrete mixture and mortar were measured. In terms of the experimental results ,the mechanism of PP fiber influencing dense degree of concrete mixture and mortar , concrete intensity and toughness were analyzed, the related regulations was studied.The study results show that PP fiber can increase the dense degree of concrete mixture and mortar and improve the concrete intensity and toughness .3. 42 concrete specimens with the size of 100mm×100mm×400 mm weremade. After the freeze-thaw circulations (50, 100,150 times) , The weight,dvnamic modulus and the basic mechanical property such as compressive strength, splitting strength and flexural strength of the specimens were tested. In terms of the experimental results ,the mechanism of PP fiber influencing loss of the weight,dynamic modulus, intensity and toughness of concrete were analyzed ,the related regulations was studied,after freeze-thaw circulations. The study results show that PP fiber can improve the frost-resisting property of concrete.