Correlations between static and dynamic elastic modulus of a calcarenite heated at different temperatures

This paper describes the analysis performed in order to obtain the relationship between the static and the dynamic modulus of one sedimentary rock (the San Julian's stone) heated at different temperatures. The rocks have been subjected to heating processes at different temperatures (reaching up to 600 degrees C in steps of 100 degrees C), and two cooling methods for each temperature, to produce different levels of weathering on 24 cylindrical samples. The static and dynamic modulus has been measured for every specimen. Two analytic formulae are proposed for the relationship between the static and the dynamic modulus for this stone. The results have been compared with some relationships proposed by different researchers for various types of rocks. Generally low elastic modules imply highly fissured or damaged rocks. The mechanical properties, including static modulus, are highly dependent of the cracks size, orientation, and spatial distribution of these cracks. The ability to adequately detect the physical changes that affect rock mechanical capabilities by studying the propagation of ultrasonic waves has been widely discussed in many scientific papers. In this work, a high correlation between static and dynamic modules has been observed. It is concluded that in the studied range (i.e. E-dyn values lower than 50 GPa) and for the soft rocks, static modulus can be obtained from dynamic tests, being the dynamic modulus (i.e. ultrasonic waves propagation velocities) a good indicator of the material degree of deterioration. The obtained relationships will allow the computation of the static modulus of elements of cultural heritage of Alicante city made of San Julian's stone, from non-destructive field tests, for the analysis of the integrity level of historical constructions affected by high temperatures.