Performance of geopolymer concrete containing shape memory alloy and waste rubber crumb at elevated temperatures
Muhammed Maleknia,Morteza Jamshidi,Rahmat Madandoust,Morteza Biklaryan
Abstract
This study evaluates the performance of GPC modified with NiTi Shape Memory Alloy (SMA) fibers and waste rubber crumb (WRC) at elevated temperatures. For this purpose, in addition to the unreinforced concrete, mix designs with 0.25% and 0.5% of SMA and 10% WRC were designed and subjected to different tests at ambient temperature, 150°C, 400°C, 600°C and 900°C. It was concluded that at ambient temperature, SMA increases the compressive strength by 10.7%, while WRC reduces it by 27%. Moreover, at 150°C, SMA0.5 exceeded its ambient strength by 2.8%, while the other specimens experienced a decrease in strength. Then, with increasing temperature, all samples experienced a decrease in compressive strength. In addition, splitting tensile strength of the fiber specimens at ambient temperature increased up to 36%, but at 400°C decreased by about 20%, while this decrease was 48% in GPC, and the WRC experienced a decrease of about 21% at 400°C. Furthermore, the flexural strength increased by 7% with the addition of SMA, but WRC caused a 13% decrease in strength. Overall, SMA provides effective crack bridging and thermal damage reduction at all temperatures, while WRC compromises strength.
