Fracture testing of a soft rock with semi-circular specimens under three-point bending. Part 2—mixed-mode

Abstract The objectives of this experimental investigation are to evaluate the semi-circular specimen under three-point bending (SCB) technique for fracture testing of rocks and to determine the fracture properties of a water-saturated synthetic mudstone. In this paper, the SCB technique was employed to determine the Mode I fracture toughness of the mudstone. In a companion paper (Part 2), the mixed-mode fracture toughness of the mudstone was determined using the same technique. This study affirms the use of the SCB technique because of the simplicity of specimen preparation, laboratory set up and test procedure. Also, very small core-based specimens may be utilised and only conventional fracture toughness testing equipment is required. Hence it is cost-effective in that it requires minimal rock material and effort to use. This technique provided reliable results that are comparable with more established Mode I fracture testing methods.

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