Mechanical properties of light weight concrete at elevated temperature

Abstract

This study provides an experimental investigation on the mechanical properties of concrete with thermal expansion at elevated temperatures. To understand the mechanical properties at elevated temperature, normal and light weight concrete of 60 MPa grade was exposed to temperature range 20 (room temperature) to 700oC under 0.0 fcu (compressive strength of concrete at room temperature, fcu), 0.2 fcu, 0.4 fcu load conditions and compressive strength, elastic modulus, thermal strain and creep at target temperature were inspected. Experimental results show that light weight concrete has higher compressive strength, although the strength of normal weight concrete degenerated more sharply than the light weight concrete at elevated temperature. Moreover, the thermal strain (0.0 fcu, unstressed) and total strain (0.2 and 0.4 fcu, stressed) of normal weight concrete was higher than that of light weight concrete. The result of creep test was shown similar tendency between normal weight concrete and light weight concrete less than 300oC. Matrix damage induced by the thermal expansion of the aggregate significantly influenced on the mechanical properties degradation of concrete at high temperature.