Effects of high temperature damage on compressive and flexural behavior of high strength recycled aggregate concrete with steel fiber and crumb rubber

An experimental study was conducted to investigate the effect of high temperature damage on the compressive and flexural behavior of a new green high performance concrete-crumb rubber and steel fiber reinforced recycled aggregate concrete (RSRAC). 6 different proportions of mixture (crumb rubber content including 0%,4%,8%,12% and 16% by volume) and 4 different temperature damages (25 ℃, 200 ℃, 400 ℃ and 600 ℃) were considered in this study. A total of 72 cylinders of 150 mm×300 mm were cast and tested under axial compressive loads, and 72 flexure specimens of 150 mm×150 mm×550 mm were cast and tested under three point bending. The effects of crumb rubber content and temperature damages were analyzed on failure mode, compressive and flexural strength, elastic modulus, toughness, etc.. The results show that both the compressive strength and flexural strength of RSRAC considerably decrease with the increase of the temperature, and the relationship between compressive strength and temperature is nearly linear, as well as the relationship between the flexural strength and temperature; the addition of suitable rubber content is benefit for the compressive and flexural properties of RSRAC. Taking account into the effect of the different temperatures, when the rubber content is 4%-8%, the compressive and flexural strength and elastic modulus of RSRAC are the best, while 8%-12% is the optimal amount of rubber for the flexural strength of RSRAC. © 2016, Editorial Department of China Journal of Highway and Transport. All right reserved.