

Experimental Study on Mechanical Properties of Ultra-high Strength Concrete at Elevated Temperatures
Abstract
This paper introduces experimental study on mechanical properties of an ultrahigh strength concrete at elevated temperatures. The compressive strength on cylinders and modulus of elasticity of the ultra-high strength concrete (fc = 166 N/mm2) were investigated up to 800°C. The temperature dependent mechanical properties were compared with those of normal/high strength concretes provided in Eurocode 2 and ANSI/AISC 360-10, and with those of concretes in literature. The comparisons showed that the compressive strength and elastic modulus of the ultrahigh strength concrete were generally reduced less than those of normal/high strength concretes at elevated temperatures, indicating higher fire resistance when it is used in structural load-bearing elements. The temperature-dependent mechanical properties are proposed to evaluate fire resistance of concrete filled tubes using the ultra-high strength concrete in high-rise buildings.