Temperature effects on mechanical behaviour of engineered stones

In this research, three types of artificial or engineered stones were compared against two types of natural stones (a limestone and a granite) in what concerns to temperature, thermal ageing and thermal shock effects on flexural strength and Young’s modulus. Temperatures of the thermal treatments, in the range from 20 to 200 °C, were intentionally chosen to simulate some practical applications of this kind of materials, for example, when they are used as kitchen tops. The results reveal the different characteristics of the materials. When tested at temperatures up to 100 °C, engineered stones show much higher values of flexural strength compared to the natural stones; and when tested at ambient temperature after being submitted to rapid cooling (thermal shock) from 200 °C down to 20 °C, engineered stones continue to show higher values of flexural strength compared to the natural stones. For the temperature range from 20 to 200 °C, thermal shock and thermal ageing effects on Young’s modulus are not very pronounced. Young’s modulus (E) of each of the materials was determined at ambient temperature, and the engineered stones keep almost the same value of E after thermal ageing or thermal shock up to 160 °C.