Jordan Journal of Civil Engineering

Mechanical Properties and Microstructure Characteristics of Self-Compacting Concrete with Different Admixtures Exposed to Elevated Temperature

Authors:

Balamurali Kanagaraj; Anand N; Diana Andrushia; Mervin Ealiyas Mathews; Johnson Alengaram;

Abstract:

Self-Compacting Concrete (SCC) is a composite material with ingredients having different thermal properties, and it is very difficult to study the fire resistance property. Each SCC mix ingredient possesses different properties based on moisture content and its porosity level. Therefore, it is necessary to study the performance of SCC exposed to elevated temperatures. The present investigation examines the SCC�s age and cooling type after exposed to elevated temperatures (air-cooled and water-cooled) and compares them to Normal Conventional Concrete (NCC). Two types of concrete, i.e., NCC and SCC, were developed and studied for the early age and residual strengths. SCC was developed with three different types of admixtures, namely, Fly Ash (FA), Silica Fume (SF), and Metakaolin (MK) as binder materials, by replacing the cement. The mechanical characteristics of FA and SF blended SCC before heating show similar results, whereas MK-based SCC possesses greater strength than other mixes. In the case of specimens exposed to high temperature of 1000 ℃, MK-blended SCC produced the lowest residual strength compared to FA and SF-based mixes. Further microstructural investigation was conducted to examine the internal structure of the specimens exposed various heating temperatures. From the results, it is concluded that the higher the strength gain upon aging, the greater the strength loss upon temperature rise.

Keywords:

Self-compacting concrete, Fly ash, Silica fume, Metakaolin, Curing age, Residual strength, Microstructure.