Enhancement of compressive strength and strain ductility of SMA fiber reinforced concrete considering fiber's aspect ratios

초록

In this study, the effect of recovery stress on the toughness of cementitious materials was investigated using randomly distributed SMA fibers in concrete. The composite was reinforced by cold drawn crimped SMA fibers due to their great potential in developing a prestressing effect as well as providing sufficient bond resistance. To this end, considering the same volumetric fraction, different aspect ratios of the SMA fibers were embedded into the matrix and then molded into different reinforced concrete cylinders. Compression tests were performed where several parameters, including compressive strength, ductility, axial, and volumetric strain were examined before and after inducing the prestressing effect. Furthermore, the present study dealt with fracture modes, as well as internal and surface crack analysis via X-ray and digital image correlation (DIC) equipment to investigate the effect of prestressing with different aspect ratios. The results showed that not only the current geometry of SMA fibers in concrete could improve the ductility of the composite, but also elevate the compressive strength demonstrating a considerable rise in energy absorption capacity. © 2022 Elsevier Ltd

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