Crack Coalescence in Molded Gypsum and Carrara Marble: Part 1. Macroscopic Observations and Interpretation

摘要: Cracking and coalescence behavior has been studied experimentally with prismatic laboratory-molded gypsum Carrara marble specimens containing two parallel pre-existing open flaws. This was done at both the macroscopic microscopic scales, results are presented in separate papers. paper (the first of two) summarizes experimental investigates influence different flaw geometries material, on cracking processes. In companion (also this issue), most deformation processes shown present will be related to underlying changes. study, a high speed video system used, which allowed us precisely observe mechanisms. Nine crack categories types trajectories were identified. The inclination angle (β), ligament length (L), that is, intact rock between flaws, bridging (α), line linking up inner tips, had effects patterns. One pronounced differences observed during compression loading test development white patches prior initiation cracks marble, but not gypsum. Comparing behaviors tested materials, tensile generally occurred more often than for same pair geometries.