White Patches In Marble Test Specimen

The procedures to test absorption astm c97 and its counterpart en 13755 determination of water absorption at atmospheric pressure use a similar sized specimen with a similar procedure.

White patches in marble test specimen.

Coloured marbles are again classified based on their colour and have different properties. The white patches usually appear prior to the peak stress of the specimen. The shear cracks usually initiate at or near the flaw tips and propagate to form x or half x shear belts that dominate the. The dynamic increase factor is computed revealing a strong strain rate dependence of the carrara marble when subjected to strain rates above 1 s 1.

The sem study identified that the white patches in marble were associated withnmicrocracking zones process zones. The parallel esem study on gypsum showed that the extent of process zone development associated with macroscopic tensile cracking wasnless. White marbles are generally plain white marble with coarse grains predominantly showing mica particles giving reflection in light. These stuns are the result of tiny explosions inside the crystal of the stone.

The shear cracks usually initiate at or near the flaw tips and propagate to form x or half x shear belts that dominate the macroscopic failure under impact loading. The white patches usually appear prior to the peak stress of the specimen. Similar to the quasistatic loading tests conspicuous white zones patches commonly appear prior to the initiation of visible cracks in the dynamic loading tests. When the impact number is large the dynamic three point bending fracture of the specimens is manifested as a non pure tensile failure fig.

In general for marble specimens under uniaxial compression the white patches occur much earlier before the appearance of visible cracks which accompany the specimen failure. Pin point pressures placed on the marble cause these marks. The primary difference is the mode of immersion in which case the astm method immerses the test specimen completely without delay. The appearance of shear white patches may be caused by the weak interfaces or damage zones inside marble specimens.

11 e and f. The ratio of the stress corresponding to the first white patch occurrence around the flaw to the peak stress attained in the specimen is found to vary with the loading conditions. Conspicuous microcracking zones in the form of white patches commonly appear much earlier before the development of macro cracks. Marbles are classified broadly classified as white marble and coloured marble.