Tensile and flexural properties of ultra high toughness cemontious composite

The tensile and flexural properties of polyvinyl alcohol (PVA) fiber reinforced ultra high toughness cementitious composite (UHTCC) were investigated. The composite, tested at the age of 14 d, 28 d and 56 d, shows extremely remarkable pseudo strain hardening behavior, saturated multiple cracking and ultra high ultimate strain capacity above 4% under uniaxial loading. Also, the corresponding crack widths are controlled under 50 mu m even at 56 days age. In the third point bending tests on thin plate specimens, the composite shows ultra high flexural ductility and multiple cracking on the tension surface. The high ultimate flexural strength/first tensile strength ratio of about 5 verifies the pseudo strain hardening behavior of UHTCC. SEM observation on fracture surfaces provides indirect evidence of optimal design for the composite.