Shaking Table Test of Rural Masonry Structure Reinforced with High-Ductility Concrete

Single-story unreinforced masonry rural houses along the Tanlu Earthquake Belt in Anhui Province are generally constructed without ring beams and tie columns, resulting in poor structural integrity and low seismic performance. This paper proposes a convenient single-sided High-Ductility Concrete Strip (HDCS) retrofitting method. Two 1:2 scaled test specimens, namely the unretrofitted model M1 and HDCS single-side retrofitted model M2, were fabricated for shaking table tests. Systematic analyses were carried out based on white noise sweep tests, failure modes, acceleration responses and inter-story displacement responses. The test results show that HDCS possesses excellent tensile capacity, which forms continuous confinement at wall joints and openings to boost structural stiffness and greatly restrain post-seismic stiffness degradation, as well as achieve more uniform structural deformation distribution. Under strong seismic excitations, the unretrofitted model suffers severe damage, including penetrating diagonal shear cracks and separation between gable walls and lower walls. In contrast, damage of the retrofitted model is concentrated within the HDCS overlay, realizing damage redistribution and preventing brittle failure of the main masonry. HDCS stabilizes the distribution of acceleration amplification factors and restrains wall rocking and stress concentration around openings. Although single-sided strengthening induces slight out-of-plane effects, its adverse influence is acceptable.