Experimental determination of softening relations for cement-treated sand

Three-point bending tests and plane strain compression tests were conducted to investigate tensile and shear failure in cement-treated sand. The bending test results were used to evaluate the tension fracture energy and crack opening displacements. From these results, the tension-softening relation was obtained using the energy balance approach. In the plane strain compression tests, the strain localization zone that occurs during a strain-softening process and the local displacements across the shear band were identified by an image analysis. The shear-softening relation and the energy consumed during the shear failure were estimated based on these local displacements. After the test, the shear bands that appeared on the specimen surface were observed with a microscope. This microscopic observation revealed the appearance of shear fracture zone and provided information on the thickness of the shear band. Moreover, we discussed the difference in the energies consumed by the tensile failure and the shear failure.