Study of coarse and fine natural aggregates at high temperature in Algeria

Under high temperature, concrete undergoes changes which occurred in the hardened cement past and aggregates. These changes modified the mechanical and physical properties of concrete. The main objective of this study is to observe and identify the influence of high temperature on the physical properties of different nature of aggregates used to cast concrete. Four types of aggregates were studied in this research, siliceous sand (SS), calcareous sand (CS), white calcareous aggregates (WCA) and gray calcareous aggregates (GCA). These aggregates were subjected to different temperatures, from 100°C to 900°C. The mass loss, absorption coefficient, water porosity and density were determined before and after the exposure to the high temperatures. The results show that gray calcareous aggregates (GCA) suffered more deterioration than the other types of aggregates after the high temperature exposures. The results presented in this paper allow improving the knowledge of aggregate’s deterioration phenomena and the evolutions of physical properties of these different aggregates can be used to explain the evolution of physical and mechanical properties of concretes.