Cyclic tests on slip resistance of squat heavyweight concrete shear walls with construction joints

Abstract

The objective of this study was to examine the effectiveness of different slip-resistance bars (X-, W-, and Ω-shaped bars) on reducing sliding shear displacement at the base interface of squat heavyweight concrete (HWC) shear walls with construction joints. In addition, the structural applicability of welded wire fabric (WWF) reinforcement was investigated as an alternative to the individual deformed bars conventionally used for the shear reinforcement of shear walls. All the wall specimens had the same concrete dry density of 3380kg/m3, geometrical dimensions with barbell-shaped cross-sections, and shear ratio of 1.0. The ultimate failure of the walls subjected to under constant axial loads and reversed cyclic lateral loads was associated with a kinking in the longitudinal and vertical shear bars and splitting of the surrounding concrete at the base interface due to the dowel resistance of the bars. The slip-resistance bars were effective in reducing the shear slip displacement at the base interface after the peak load of the walls was reached. The WWF reinforcement performed comparably to the conventional shear reinforcements in enhancing the shear strength of the squat shear walls and preventing a rapid decrease in the applied loading after the peak strength. The shear strength of the squat HWC shear walls can be conservatively estimated using equations proposed by EC8 for earthquake resistance, even for avoiding sliding shear failure at high wall drift ratios.