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 30 mm ECC overlay applied to the tensile surface of the wall provided a maximum out-of-plane strength increase of 1267%. When a 30 mm overlay was applied on the wall compression surface and an additional grade 300 MPa 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.