Experimental study on improving super high-strength concrete toughness by high modulus PVA fiber

The significant brittleness with low tensile strength of super high-strength concrete (SHSC) restricted its application in seismic region. In order to overcome this problem, a series of experimental studies performed by adding the new modified PVA fiber into super high-strength concrete, which had high modulus elasticity and tensile strength. When the PVA fibers were added at the volume fractions of 0.17%, 0.25%, 0.33%, and 0.5%, the compression strength increased slightly because of adding PVA fiber, only being 2%-8.2% improvements. But the splitting tensile strength increased greatly, being 22%-46.7% improvements. PVA fibres were also added to SHSC columns in three different percentages of 0.17%, 0.33%, and 0.5% by volume of concrete in order to study seismic toughness. Compared with plain super high-concrete column, the ultimate displacements and total energy dissipations of PVA fiber columns, had 42.6%-54.1%, 184.4%-318.3% improvements, respectively. The test results indicated that adding PVA fiber into super high-strength concrete can reduce the brittleness and better the toughness greatly, and the applications of SHSC columns in seismic regions may be relaxed.