The effect of flaw geometry and infilling on crack initiation, propagation, and coalescence of a parallel flaw pair in marble

Abstract A series of uniaxial compression tests were conducted on unfilled or filled marble specimens with a parallel flaw pair to study the effect geometry and infilling crack coalescence pattern. Special attention was paid initiation, propagation, processes, which traced by CCD camera digital image correlation (DIC) technique. The experimental results have shown that appearance white patch strain localization band precedes initiation macroscopic crack. tensile evolves from narrow patches clear boundaries, while shear wider blurry boundaries. high-strength fillers suppress propagation cracks (i.e., T1, T2, T3) promote coplanar mixed tensile-shear M1, M2, S1). variation in condition leads difference fundamental types, hence resulting different patterns for given geometry. For small rock bridge angles β = 30°, 45°), no indirect tends occur between open gypsum-filled flaws, is prone cement- resin-filled flaws. are dominated medium 60°, 90°), but stress peak strength greatly affected conditions. large angle 120°), increase filler generate straighter wing at promotes additional outside bridge.