Enhancing the performance of concrete specimens using shape memory alloy fibers

The use of fibers in concrete creates special properties in it, and with the help of fibers, stronger concrete can be made and this high-consumption material which causes a great reduction in the cost of maintaining the structure can be used in various constructions. Shape Memory Alloy (SMA) is a material having very special properties. In this research, using these fibers in three volume percentages of ۰.۱, ۰.۳, and ۰.۵, in a period of ۲۸ days, tests of compressive strength, second compressive strength, splitting tensile strength, flexural strength, and Ultrasonic Wave Velocity (UPV) were performed on concrete samples. The results were compared with concrete without fibers and showed that the use of SMA increases the mechanical properties of concrete and the peak of this increase occurred when ۰.۵% of SMA was used in the concrete structure and it promoted the compressive strength to ۱۱%, splitting tensile strength and flexural strength to increase by ۱۸% and ۱۵% respectively compared to the control sample based on Ordinary Portland Cement (OPC). It should be noted that the results of the secondary compressive strength test on the samples showed that the use of SMA in the concrete structure after the failure of the samples and before reloading the cracked samples has a positive effect and prevents the crushing of the samples and causes Continuity of the concrete structure which is maintained even after failure. In this way, it is concluded that the use of SMA in concrete structure is very useful and appropriate.

Keywords:

Shape Memory Alloy , reinforced-concrete , mechanical properties , compressive strength , splitting tensile strength , flexural strength