The Effect of Egyptian Calcined Clay on Residual Compressive Strength after Concrete Exposure to High Temperatures: A Model Case

Document Type : Original Article

Authors

1 Professor of Properties and Strength of Materials, Faculty of Engineering, Civil Engineering Department, Suez Canal University, Ismailia, Egypt

2 Civil Engineering Department, Higher Institute of Engineering and Technology in New Damietta, Damietta, Egypt

Abstract

Kaolin is a naturally clay mineral, primarily composed of the mineral kaolinite. When kaolin is subjected to the calcination process, it becomes a highly beneficial material with cementitious hardening properties. Certainly, the composition and effect vary depending on the source of the kaolin. Kaolin ore is found in Egypt in several areas and in large quantities. Therefore, Egypt exports kaolin ore and produces calcined clay from kaolin. This scientific paper focuses on studying the impact of Egyptian calcined kaolin clay as an enhancer of concrete's resistance to fire and high temperatures. The purpose was to use calcined clay to produce a special concrete suitable for structures that may be exposed to fire or high temperatures. Nine concrete mixtures were prepared. The control mix was designed to have medium compressive strength. Eight mixtures with partial replacement of Portland cement with Egyptian calcined clay from kaolin (K) were performed. Concrete specimens were subjected to high temperature at 700°C for one hour. After that, specimens were cooled with water. The reduction in compressive strength after heating and cooling was measured. The results show that the addition of Egyptian calcined clay in concrete improves the residual compressive strength after heating and cooling. The research suggests using Egyptian calcined clay in the concrete of facilities that may be exposed to fire or high temperatures.

Keywords

Main Subjects