Seismic shear behavior of masonry walls strengthened with engineered cementitious composites (ECC)

Engineered cementitious composites (ECC), a type of high-performance fiber reinforced cementitious composites characterized by its extraordinary tensile properties and strain-hardening behaviors, are effective for strengthening buildings, especially masonry structures with poor seismic performance. This research focuses on an experimental and analytical investigation to evaluate the effectiveness of ECC overlays in strengthening masonry walls. Reverse cyclic tests were conducted on three un-strengthened masonry walls and five walls strengthened with ECC overlays on single or double sides. The impact of factors such as vertical stress, mortar strength, and ECC overlay thickness on the seismic performance of these walls was also examined. Key parameters, including seismic shear capacity, hysteresis behavior, energy dissipation, and stiffness, were analyzed for walls subjected to various strengthening methods. Results show that ECC overlays with thicknesses of 10 mm-20 mm significantly improve the strength, ductility, energy dissipation, and load-bearing capacity of masonry walls, making ECC a promising retrofitting solution. Furthermore, a theoretical model was developed to predict the shear strength of ECCstrengthened masonry walls. The analytical predictions closely align with the experimental results, confirming the reliability of the proposed model for estimating the seismic shear capacity of ECC-strengthened masonry walls.