Evaluation of the influence of shape memory alloys and zeolite on the mechanical properties of concrete

Nowadays, concrete utilization has been welcomed by engineers all over the world for reasons such as proper performance and economic efficiency in construction and maintenance. Using all kinds of additives, such as industrial, mineral, waste, fibers, etc., is well received more than ever. In this research, using cut shape memory alloys (SMA) and zeolite (ZEO) and performing tests of primary and secondary compressive strengths, splitting tensile strength, flexural strength and ultrasonic pulse velocity (UPV) in a period of 28 days, an attempt was made to examine the mechanical characteristics of concrete. According to the obtained results, the use of 0.3% of SMA increases all the resistance parameters of concrete. Furthermore, replacing 10% of ZEO with cement increases the tensile and flexural strength, and using the combination of 10% ZEO and 0.3% SMA was the most successful mixture design of this research that has been able to improve the compressive strength by 2%, splitting tensile strength by over 14%, and flexural strength by approximately 12% compared to the ordinary Portland cement (OPC). By observing the behavior of samples containing SMA in the secondary compressive strength test, it was found that this material is also useful in concrete retrofitting. Moreover, it was found that the compressive strength of mixtures containing ZEO and SMA has a strong correlation with UPV and secondary compressive strength results, respectively. Finally, it is suggested that the simultaneous use of ZEO and SMA in concrete structures can be very beneficial.