Effect of high-temperature on the mechanical and durability behaviour of concrete

Abstract

The post-fire response of building elements on mechanical and durability characteristics plays a vital role in influencing the overall strength and serviceability parameters of the structure. This research work presents the experimental investigations carried out to study the effect of elevated temperature on the durability characteristics of Normal Concrete (NC). Concrete specimens of different strength grades (M20, M30, M40, and M50) were cast, cured, and tested for compressive strength, water absorption, sorptivity, acid resistance, chloride penetration and permeability. The results demonstrated that the M50 grade concrete specimens exposed to higher temperature exhibited higher strength loss i.e., 46.10% when compared to other grades. Also, the strength loss of higher grade heated concrete specimens subjected to sulphate attack and chloride attack (acid resistance tests) was found to be higher than that of concrete specimens with lower grades, and it was 26.80% and 21.63% respectively. Weight loss on specimens exhibited proportional variation to the strength loss. As the strength grade of concrete increases, the mechanical and durability characteristics were found to be improving for unheated specimens. However, in the case of heated specimens, a substantial drop in performance was observed.