Active Reinforcing Fiber of Cementitious Materials Using Crimped NiTi SMA Fiber for Crack-Bridging and Pullout Resistance

Materials

HaVinh Ho¹  Eunsoo Choi¹  Jong-Su Jeon² 

[1] Department of Civil Engineering, Hongik University, Seoul 04066, Korea;Department of Civil and Environmental Engineering, Hanyang University, Seoul 04763, Korea;

关键词: active reinforcing fiber;    shape memory alloy;    cold drawing;    crimped fiber;    NiTi SMA;   

DOI  :  10.3390/ma13173845

来源: DOAJ

【 摘 要 】

This study investigated the recovery stress and bond resistance of cold drawn crimped SMA fiber using two different initial diameters of 1.0 and 0.7 mm. These characteristics are important to the active prestressing effect and crack-closing of the fiber. NiTi SMA fiber was used for the cold drawing, and then crimped shapes were manufactured with various wave heights. After that, tensile, recovery, and pullout tests were conducted. The cold drawn crimped fiber showed softening tensile behavior more clearly than the cold drawn straight fiber when not subjected to heating, whereas they had the same tensile behavior under heating. The recovery stress and the residual stress of the crimped fibers were less than those of the straight fiber with the same diameter. Moreover, crimped fibers with a large diameter and higher wave height would induce more recovery stress and residual stress. The maximum pullout resistance of the crimped fiber was a function of the wave depth, embedded length, yield strength, and flexural rigidity of the fiber.

【 授权许可】

Unknown