Issue 39

H. Xiao et alii, Frattura ed Integrità Strutturale, 39 (2017) 181-190; DOI: 10.3221/IGF-ESIS.39.18

Figure 2 : Mass changing rate after heating.

Figure 3 : Volume changing rate after heating.

Figure 4 : Density changing rate after heating.

Grains with different compositions, structures and coefficients of linear expansion expand when the granite is heated at certain temperature. As a result, the stress inside the rock exceeds yield strength limit of grains, thus causing damage on crystal. Therefore, cracks grow in the place where stress concentrates or preexisting defects generate and expand. When the temperature exceeds 400 °C, the internal stress increases sharply and the number and length of cracks increase faster, which indirectly results in the expansion of the granite.

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