Abstract:
An experimental program was undertaken with the principal aim of determining the transition point between the stair-step failure mode and diagonal tension failure mode of eight 1200 mm x 1200 mm URM wall panels when subjected to simulated earthquake lateral loads. Preparations included the formulation of mortar compositions and then subsequent pairing with bricks of varying strengths to replicate the range of material characteristics of existing URM structures found throughout New Zealand. Diagonal shear tests were conducted with experimental results indicating two distinct failure mechanisms. It was concluded that the transition between failure modes occurs when the mortar to brick compressive strength ratio is approximately 0.4. In addition, following the failure of the wall panels, three panels were repaired using 8 mm steel wire rope placed in differing orientations and quantities in order to investigate the feasibility and performance of this repair technique. Steel wire rope proved to be a simple and cost effective remediation method with improvements in diagonal shear strength and displacement capacity of up to double and fifty times respectively that of the as-built counterparts.