Shaking-Table Test on a Two-Story Timber-Framed Masonry Structure Retrofitted with Ultra-High Ductile Concrete

Abstract

Timber-framed masonry structures were widely used in eastern Asia as residential buildings. Due to a lack of seismic design, they are vulnerable to major earthquakes. To date, there are limited technologies available for strengthening this category of building with efficiency, safety, and acceptable cost. This study looked at the feasibility of using ultra-high ductile concrete, a type of engineered cementitious composite with a tensile strain capacity exceeding 8%, as a structural material for strengthening timber-framed masonry structures. The one-half-scale Chuan-dou timber-framed masonry structure was tested on a shaking table to effect serious damage; then ultra-high ductile concrete was sprayed on the masonry walls for retrofitting and further strengthening. The seismic analyses of the structure before and after retrofitting were compared, including damage patterns, dynamic properties acceleration response, and displacement response. Even under a seismic intensity of 9.0, the maximum interstory drift of the ultra-high ductile concrete retrofit structure was 0.40% and 2.00% in the longitudinal and lateral directions, respectively. Experimental results demonstrate that ultra-high ductile concrete layers significantly enhance stiffness, ductility, and damage-resistant performance. This research provides a reference for the application of ultra-high ductile concrete layers to retrofit masonry structures.