Experimental study of crack propagation in calcite rocks

Experimental curves relating the crack propagation velocity vs the stress intensity factor K1 were established for a micrograined (1–4 μm) limestone (micrite) and for a fine-grained (100–300 μm) marble. The environment was partly CaCO3 saturated water at 20°C. From these curves V = V(K1), it was possible to calculate the relations between stress and time-to-failure and between fracture stress and deformation rate. These calculated relations were verified experimentally by other tests. The correlation appear to be excellent.