Out-of-plane Testing of Unreinforced Masonry Walls Strengthened Using ECC Shotcrete

Abstract

The use of Engineered Cementitious Composite (ECC) shotcrete and near surface mounted steel reinforcing bars as a seismic strengthening intervention for unreinforced masonry (URM) walls is reported. Six out-of-plane tests were conducted on five clay brick masonry walls through the application of uniformly distributed loads using inflated airbags.A 30mm ECC overlay applied to the tensile surface of the wall provided a maximum out-of-plane strength increase of 1267%. When a 30mm overlay was applied on the wall compression surface and an additional grade 300MPa D20 deformed reinforcing bar was embedded in the ECC overlay, a 336% increase in out-of-plane strength was measured. These results show that the application of ECC onto URM walls can significantly improve their out-of-plane capacity. The increases in wall out-of-plane strength due to the ECC seismic intervention were predicted using conventional design procedures and a seismic design methodology using this approach is proposed.