Experimental study on mechanical properties of ultra-high toughness fiber reinforced cementitious composite

A type of ultra-high toughness cementitious composite reinforced by polyvinyl alcohol fibers was developed. The tensile strength, flexural strength and breaking resistance of this type of material were studied by uniaxial tensile tests, uniaxial compressive tests, four-point flexural tests and three-point flexural fracture tests. The results show that this type of ultra-high toughness cementitious composite exhibits the characteristics of pseudo strain-hardening, multiple cracking and high ductility as well as high energy absorption. The crack width at ultimate load is about 50 μm. The ultimate strain excesses 3% and the average crack space is about 1mm. The compressive strength is similar to that of concrete but the elastic modulus is lower and the compressive deformation capacity is much higher than that of concrete. The three-point flexural fracture test results demonstrate that the ultimate load and corresponding deformation of this type of composite are much higher than those of its matrix. The test results of notched specimens show that the single cracking in this composite can be split into multiple small cracking and the composite is insensitive to small notch. All test results demonstrate that this type of composite can keep integrality very well at its failure rather than the happening of fragmentation.