Pre-fabricated TRC Panels Versus TRM Jacketing for Integrating Seismic and Energy Retrofitting: Bi-Directional Shaking Table Tests on Three Masonry-Infilled RC Buildings

Abstract

Two novel integrated seismic and energy retrofitting solutions for existing buildings are experimentally assessed in this study. Three 60%-scaled, two-storey infilled reinforced concrete buildings underwent a series of bi-directional shaking table tests. The control building represented a part of a typical Korean school building with seismic design deficiencies and suffered out-of-plane (OOP) failure of the second-storey infill panels at maximum considered earthquake. Two retrofitting schemes based on textile-reinforced cement-based composites were evaluated as follows: (1) newly developed ‘textile capillary-tube panels’ (TCPs), namely pre-fabricated textile-reinforced concrete (TRC) with integrated capillary tubes, and (2) a combination of textile-reinforced mortar (TRM) with thermal insulation. Additionally, the presence of openings in the infills, as well as the effect of different types of anchorage of the textile reinforcement were studied. At the design level earthquake, both retrofitted buildings presented next to no damage, compared to the control structure that was in a state of near-collapse. The retrofitted structures reached double the intensity of the design earthquake, with the shaking table reaching its maximum acceleration capacity, yet no irreversible damage was observed. The strength increase for both retrofitted buildings was +110% compared to the un-retrofitted building in the direction with openings, in which both buildings were retrofitted with TRM. For the fully infilled direction, the TRM-retrofitted building recorded more than double the inter-storey drifts compared to the TCP-retrofit, and reached its peak strength (+120% compared to the control building). The TCP-retrofitted building, instead, displayed a stiffer response with reduced deformations due to the carbon textiles employed in the precast panels. For both retrofits OOP damage was prevented, also demonstrated by the measured accelerations at the centre of the infills.