Effect of polyvinyl alcohol fiber on the cracking risk of high strength concrete under uniaxial restrained condition at early age

Abstract

Fiber materials with toughening effect can enhance the tensile strength of concrete, reduce shrinkage, and decrease the possibility of concrete cracking. Despite substantial previous researches, the effect of polyvinyl alcohol fiber (PVAF) on the cracking risk of high strength concrete (HSC) under the uniaxial restrained condition and adiabatic curing mode is hardly investigated. Accordingly, the early-age temperature, autogenous shrinkage (AS), creep, and restrained stress of concrete reinforced with different volume fractions of PVAF (0%, 0.2%, 0.4%, and 0.6% of concrete by volume, respectively) under the uniaxial restrained condition and adiabatic curing mode were further investigated in the current research. The cracking risk of HSC reinforced with different volume fractions of PVAF was estimated based on the test results. The AS decreased, while the temperature drop, cracking age, cracking stress, and cracking stress/axial tensile strength of HSC increased with increasing PVAF volume fraction. The incorporation of PVAF increased the early-age compressive creep and tensile creep of HSC. The cracking risk of HSC estimated by the stress reserve or integrated criterion decreased with increasing PVAF volume fraction.