Effects of Vehicle-Induced Vibrations on the Tensile Performance of Early-Age PVA-ECC

Polyvinyl alcohol-engineering cementitious composites (PVA-ECCs) have been widely applied in bridge deck repairing or widening, and a common practice is that a portion of the bridge is left open to traffic while the closed portion is constructed, which exposes the early-age PVA-ECC to vehicle-induced vibrations. However, whether vehicle-induced vibrations affect the performance of early-age PVA-ECC remains unknown. The purpose of this study was to conduct laboratory test programs to investigate to what extent vehicle-induced vibrations soon after installation affects the tensile performance of the PVA-ECC. A self-improved device was used to simulate the vehicle-induced vibrations, and after vibrating with the designed variables, both a uniaxial tensile test and a grey correlation analysis were performed. The results indicated that the effects of vehicle-induced vibrations on the tensile performance of early-age PVA-ECCs were significant, and they generally tended to be negative. In particular, for all of the vibrated PVA-ECC specimens, the most negative effects occurred when vibration occurred during the period between the initial set and the final set. We concluded that although vehicle-induced vibrations during the setting periods had no substantial effects on the inherent strain-hardening characteristics of PVA-ECCs, the effects should not be ignored.