Double shear experiment of highly ductile concrete modified by polyvingl alcohol and shear toughness evaluation method

In order to study the shear property and shear toughness evaluation method of highly ductile concrete(HDC), 5 sets of HDC specimens, 1 set of matrix specimens (without fiber) and 1 set of concrete specimens were designed for comparison. Through double shear experiment, fiber volume fraction and HDC compressive strength were set into parameters to analysis the modes of shear failure, shear strength of HDC specimens and deformation at peak load. Based on the results of experiment, shear toughness evaluation method of HDC double shear experiment was built. The research shows that:with the bridging action of fiber in HDC and during fiber pull-out, it has absorbed considerable energy. The shear failure mode of HDC specimens is ductile failure; Compared with concrete and matrix specimens, the shear strength and the deformation at peak load of HDC specimens are substantially improved, and its range of improvement increases with the increasing number of fiber volume fraction; With the increasing of HDC compressive strength, the shear strength of the HDC specimens increases gradually, and the shear deformation at peak load decreases gradually; Using initial energy density and residual shear toughness ratio to evaluate the shear toughness of HDC materials, the shear toughness of HDC specimen has a significantly higher level than concrete and matrix specimens.