Experimental evaluation of the out-of-plane behavior of a traditional timber frame with mud and rubble infill wall strengthened by a polypropylene band mesh on one side

Abstract

The structural integrity of traditional Chinese village residences may be compromised due to inadequate connections between the timber frame and infill walls, coupled with the weak cohesiveness of clay mud. Among the various damage mechanisms resulting from earthquakes, the out-of-plane collapse of infill walls is a recurrent and significant concern. The goal of this research is to investigate the feasibility and effectiveness of a polypropylene (PP) band mesh reinforcement approach for a traditional timber frame with mud and rubble infill walls. The ultimate goals are to prevent out-of-plane collapse, improve the collaborative performance of the structure, reduce seismic vulnerability, and safeguard the architectural heritage of traditional dwellings. With careful consideration of their aesthetics, the study centers on timber frames with mud and rubble infill walls strengthened by a polypropylene (PP) band mesh and cement mortar on one side. A series of experiments were conducted based on out-of-plane cyclic one-way tests of four full-scale specimens. Different loading surfaces and reinforcing PP grid sizes with and without window openings were investigated to characterize the out-of-plane behavior of the reinforced hybrid walls. The damage evolution, failure modes, force–displacement curves, out-of-plane profile characteristics, stiffness, strength, and energy dissipation were described. All the reinforced walls exhibited marked improvements out-of-plane lateral capacity, with enhancements of approximately 120% and 162%, and stiffness increases of approximately 105% and 200%, compared to the unreinforced walls. The minimal out-of-plane displacement observed on the reinforcement side was also accompanied by significant increase in integrity and ductility.