Strengthening of Unreinforced Masonry Buildings

Abstract

A method is proposed for rehabilitation and strengthening of multiwythe unreinforced brick masonry walls in buildings where they are the primary structural element for transferring load to the foundation. Shear tests were performed to determine the strength of newly manufactured small‐scale specimens made with cement grout, sand/polyester grouts, and sand/epoxy grouts as the filler materials. Experimental tests were also performed on specimens cut out of existing (about 80‐yr old) unreinforced brick masonry walls that had been strengthened using the proposed technique. The tests were performed to determine optimum parameters such as core diameter and flow and strength characteristics of the core filler materials. The flow characteristics of sand/epoxy or sand/polyester grouts were superior to those of sand/cement grouts, but at higher costs. The primary advantages of the proposed technique include uninterrupted use of buildings, no external aesthetic alterations, and a shorter time span for the complete rehabilitation process. An ultimate strength type design technique for out‐of‐plane loads and a calculation of the equivalent modulii of the composite section is also presented.