PVA纤维对混凝土抗冻融性能的影响研究.pdf

The 12th International Symposium on Structural Engineering EFFECT OF PVA FIBER ON THE FREEZING AND THAWING BEHAVIOR OF CONCRETE Fei Xu1, Ju Chen1, Weiliang Jin1, Jihua Zhu2 1 Institute of Structural Engineering, Zhejiang University, Hangzhou 310058, P.R. China 2 College of Civil Engineering, Shenzhen University, Shenzhen, 518061, R.P. China Abstract: In this study, the effect of polyvinyl alcohol (PVA) fiber on the concrete damage under freeze-thaw condition was investigated. Experimental investigations were conduct to measure the workability, compressive strength, bending strength, total charge passed and frost resistance of PVA fiber concrete in fresh water and NaCl solution freeze-thaw environment. For frost resistance, the relative dynamic modulus of elasticity and the relative mass change of specimens at each cycle were measured. In addition, the surface deterioration of concrete specimens was also observed. Specimens having different volume content of fiber were tested in order to find the optimization PVA fiber content under freeze-thaw condition. Six series of specimens with PVA fiber volume content of 0%, 0.1%, 0.25%, 0.5%, 0.75% and 1.0% were tested. Keywords: Concrete, durability, fiber, freezing and thawing 1 INTRODUCTION Frost damage to concrete has long been the thorny issue maintaining in cold region especially that having freeze-thaw temperature. With wide application of fiber reinforced concrete, the frost damage of fiber concrete has drawn more and more attention. Significant research efforts have gone to improve and certify durability and ductility behavior of fiber reinforced concrete. Previous research shows the desirable performance of fiber reinforced concrete on tensile stress (Li et al. 2001) and strains (Lin and Li 1997) behavior as well as fatigue resistance (Li and Zhang 2002; Kenser et al. 2003). It is known that incorporation of polypropylene fiber in concrete gain satisfying durability