Issue 30

A. Spagnoli et alii, Frattura ed Integrità Strutturale, 30 (2014) 145-152; DOI: 10.3221/IGF-ESIS.30.19 151 The obtained results can be utilised as an interpretation tool for in-situ bowing measurements which often show a wide dispersion even under nominally equal environmental condition. The proposed methodology based on standard microscopic analysis of marble microstructure and on the application of an image processing code can be suggested as a first attempt for a better understanding and forecasting of the bowing evolution of monitored slabs in building façades. 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 Number of cycles [-] 0.0001 0.001 0.01 0.1 1 10 100 1000 Relative bowing, b/L [mm/m] Figure 4 : Relative bowing b/L vs number of cycles for 20 different realizations of grain orientation distribution along the slab thickness. 4 5 6 7 8 Log of number of cyles at b/L=0.001 [-] 0 0.1 0.2 0.3 Relative frequency [-] Figure 5 : Frequency distribution of the number of cycles (log scale) required to attain a relative bowing b/L of 0.1%, according to the 20 simulations of grain orientations being performed. R EFERENCES [1] Ferrero, A.M., Marini, P., Experimental studies on the mechanical behaviour of two thermal cracked marbles, Rock Mechanics and Rock Engineering, 34 (2001) 57-66. [2] Leiss, B., Weiss, T., Fabric anisotropy and its influence on physical weathering of different types of Carrara marbles, Journal of Structural Geology, 22 (2000) 1737-1745. [3] Royer-Carfagni, G., On the thermal degradation of marble, International Journal of Rock Mechanics and Mining Science, 36 (1999) 119-126.