This paper presents a review of the recent work assessing the performance of building structures strengthened with engineered cementitious composite (ECC). ECC characterizes tensile strain hardening and multiple cracking properties, as well as strong interfacial bonding performance with substrate concrete, which makes it a promising retrofitting material. A lot of researches have been conducted on reinforced concrete (RC) structures, including beams, columns, beam–column joints, and fire-damaged slabs, strengthened with ECC material, and an extensive collection of valuable conclusions were obtained. These strengthening systems usually combine ECC with FRP textiles or steel bars to form a composite strengthening layer. The review demonstrates that ECC strengthening can greatly improve the performance of RC structures.

The aim of this paper is to study the shear performance of fire-damaged reinforced concrete (RC) beams repaired by the bolted side-plating (BSP) technique. A total of six RC beams were fabricated and five were exposed to fire in accordance with standard temperature curves. Then the damaged beams were retrofitted with the BSP technique and four-point bending shear tests were conducted. The development of the temperature and deformation of RC beams under fire, the failure mode, the shear capacity and deformability, and the relative slips between the bolted steel plates and the RC beams were investigated. The displacement and strain fields were also obtained using the digital image correlation (DIC) technique. The testing results indicated that the shear capacity, stiffness, and ductility of the damaged RC beams were recovered after they were repaired by the BSP technique. The strengthening effect increases as the plate depth increases and the bolt spacing decreases. Relative longitudinal and transverse slips between the two structural components of the BSP beams were observed, and the number of anchor bolts exerted crucial influence on the degree of partial interaction between the bolted steel plates and the RC beams.

Various shape memory alloy (SMA) dampers have been developed to reduce structural vibration responses. However, the application of SMA dampers has been restricted by the high material costs of SMAs. Therefore, this study developed and tested an innovative SMA damping inerter (SDI) in which an SMA element and an inerter element were arranged in parallel and deployed in series with a supporting spring element. A single-degree-of-freedom structure with an SDI was employed to analyze the effect of vibration mitigation. A theoretical analysis was conducted via an equivalent linearization method, and parameter studies were then used to evaluate the performance of the SDI-fitted structure from perspectives of structural displacement, acceleration, and energy dissipation as well as the most efficient frequency tuning bandwidth. The performances of the SDI and a conventional SMA damper were compared by using a time-domain analysis with recorded and simulated ground motions, revealing clearly superior results for the SDI with respect to structural response mitigation, and seismic energy dissipation. The system proposed here took advantage of the full potential of combining SMA and inerter elements, making the SDI a robust system for mitigating structural vibration with more economical SMA material costs.