Mode II fracture toughness of a clay mixed with sand

Mode II fracture toughness (KIIC) is a property of material or a mechanical parameter of material. It describes the ability of a material containing a crack to resist fracture under Mode II loading conditions. In order to determine the value of KIIC of a clay mixed with sand, which was usually used as a material to fill seepage barrier, shear testing on 36 single edge cracked cube (SECC) specimens was carried out. Based on testing results, the limit of crack depth in the SECC specimen, a/W = 0.4-0.6 (where a is the crack depth, and W is the width of specimen), is suggested to determine the value of KIIC independent on crack depth. The mixing of some sand grains into clay may improve the ability of the clay to resist fracture under Mode II loading conditions because its value of KIIC increases. While sand content is about 30%, the value of KIIC reaches its maximum, which is about 192% of one without sand.