Experimental Study On Impact Resistance Of Polyvinyl Alcohol Fiber Reinforced Cementitious Composities

At present, many buildings facing various kinds of impact load.As a brittle structure,concrete has poor ability to resist impact load. Therefore, as a kind of performance material,fiber has been widely applied to practical engineering to improve concrete material defectwhich contains high brittleness, low tensile strength and poor cracking resistance. A largenumber of studies show that, fiber can improve the impact resistance of concrete.Among the many varieties of fiber, PVA fiber is concerned by many scholars for itsgood performance. How to apply PVA fiber for the structure to improve the impactresistance of building structure is need to needs to be further research and exploration.According to drop hammer impact test method recommended by ACI544committee, thisarticle research impact property for different fiber volume fractions and different fly ashinstead of PVA fiber reinforced cement composite amount of impact test to provide atheoretical basis for engineering application. The specific contents are as follows:(1) This article studies the impact of PVA fiber reinforced cement based compositeswith different fiber content on the impact damage morphology, initial crack length andwidth of crack, impact times and finally cracked the impact number. Studies found thatPVA fiber can improve the cement composite effective impact times, inhibiting thegeneration and expansion of the matrix crack.(2) This article studies the impact toughness properties of PVA fiber reinforcedcementitious composites with different fiber content, the result show that the impacttoughness properties is increases with increasing fiber content.(3)For specimen1.5%fiber content, fly ash replacing cement in proportion to record theimpact of data, the result show that the fly ash cement replacement volume in a certainrange, has the enhancement effect on the impact property of PVA fiber reinforced cementbased composite materials, more than this range, It will reduce the impact properties ofmaterials.(4) This article used the methods of mathematical statistics analysis on impact life ofPVA fiber reinforced cementitious composites, the results indicate that impact life obeyingnormal and weibull distribution.