Test Research On Flexural Toughness And Dynamic Compressive Property Of PVA Fiber Reinforced Concrete

Fiber reinforced concrete is an important means to modify concrete. With theincorporation of fibers, in the process of the concrete force, the short fiber takes theadvantages of high tensile strength and the concrete play to the advantages of highcompressive strength, thereby significantly enhance the various performance indicatorsof concrete. Fiber Reinforced Concrete increasingly widespread use in engineering, atpresent, the steel fiber, polypropylene fiber and nylon fiber are widely used in practices.The polyvinyl alcohol fiber which has high tensile strength, high elastic modulus andresistance to acid and alkali, has been used as a new reinforced material in concrete.This thesis studies the different volume content of PVA fibers for increasing withages at flexural strength and compressive strength of net cement paste and cementmortar. The experiment shows that the mixed the PVA fiber, the flexural tensile strengthof cement paste doesn’t enhance, but even the strength of flexural decrease, At lowPVA fiber content rang, the compressive strength increases with fiber content increasing.The mix of PVA fiber will increase the early flexural strength of cement mortarsignificantly, but limit the growth of the late flexural strength; Within the scope of thedosage of fiber in this article,7d compressive strength of cement mortar basic won’tchange, the14d and28d compressive strength will decrease with the increase of PVAfiber content.The flexural tensile strength experiment and compressive strength experiment ofconcrete at different volume content has been done, the flexural toughness index of PVAfiber reinforced concrete has been calculated also. The results show that the flexuraltensile strength and compressive strength of concrete increases slightly with the PVAfibers incorporation.the calculate shows that the concrete the flexural toughness indexincreased with PVA fibers incorporation, the flexural toughness index of I5, I10, I20maximum increase respectively3.73times,6.23times,8.08times than the plainconcrete.The PVA fiber reinforced concrete were analyzed by split Hopkinson pressurebar(SHPB) test, finding that PVA fiber reinforced concrete is a strain sensitive material,under impact loading, the failure stress, the peak strain, peak toughness and othertechnical indicators increases with increasing the strain rate, and its mechanicalproperties are obvious differences with the mechanical properties under static loads.In this thesis, we have obtained the influence law of basic mechanical propertiesand dynamic compression properties for concrete by PVA fiber, so that we can provide afurther research of PVA fiber concrete properties, and give a guidance to the applicationof fiber concrete.