Seismic strengthening of an unreinforced masonry building using ECC shotcrete

Abstract

An Engineered Cementitious Composite (ECC) with a tensile strain-hardening capacity of 2% was shotcreted to an unreinforced masonry (URM) building as a seismic retrofit intervention following testing that was conducted to assess the feasibility of using ECC as the retrofitting material for seismic strengthening of URM buildings. In-plane testing of 1.2 metre × 1.2 metre masonry wallettes retrofitted with ECC showed that ECC reinforcement provided a 0.15 MPa increase in shear strength for every 10 mm of ECC. Two 4.1 metre high × 1.2 metre long walls with 30 mm of ECC on a single side of each wall were subjected to out-of-plane loading to simulate face-load earthquake response. The results showed an increase in maximum load of 1.6 times the strength of the as-built wall when ECC reinforcement was applied on the compression surface and an increase of 13.2 times when ECC reinforcement was applied on the tension surface. It was concluded that ECC is a suitable material for seismic retrofitting of URM buildings and an implementation case study of a two-storey URM building shotcreted with ECC is examined.