Cyclic loading test of precast concrete load-bearing walls designed for gravitational loading

Abstract

A series of quasistatic cyclic loading tests was carried out on seven quarter-scale precast concrete bearing walls designed primarily for gravitational loading. Three of the most commonly used types of connection in Thailand were assessed: (i) welded, with short rebars, (ii) welded, with steel angles, and (iii) grouted corrugated ducts. The effects of gravitational loading at between 0 and 5·0% of wall axial load ratio were also investigated. Specimen performance was analysed in terms of observed behaviour and damage, force–drift relation and energy dissipation, with the results revealing that the walls connected using welded steel angles had less strength and ductility than the others. The gravitational load significantly affected the failure modes of the walls, with lower loadings tending to lead to deformation via a rocking mode and subsequent failure at the connections, while diagonal compression failure on the panel could occur at gravitational loads of 5%. It was also found that walls with welded short rebar connections could develop a degree of strength, stiffness, ductility and energy dissipation. Under testing against ACI ITG-5.1 criteria, the corrugated duct connections performed best, suggesting the usefulness of implementing an improved version of this connection type for construction in seismic hazard areas.