Abstract: Although Fiber Reinforced Polymers (FRPs), as alternatives for the corrosive steel reinforcement in concrete structures, have shown promising performance under gravity loads, their performance under reversal cyclic loading is still one of the main concerns. The linear behavior of FRP reinforcement has a two-sided effect on the seismic performance of FRP-reinforced concrete (RC) moment-resisting frames. Although the linear nature of FRP reinforcement could be advantageous in terms of limiting the residual damage after an earthquake event, it lowers the energy dissipation of the structure which can compromise its seismic performance. Disclosed herein is the addition of steel plates at selected locations in moment-resisting frames to improve seismic performance of FRP-RC structures while still being able to take advantage of its linear behaviour (minimal residual damage after earthquake). The effectiveness of the proposed solution was tested both experimentally and analytically.

Abstract: A length-adjustable truss stiffener is intended to be used to strengthen truss systems at locations of localized over-stress to reduce the cost from the alternative solution which is to reduce truss spacings. The stiffener consists of two or more sleeves locking around two or more components of the main truss. The sleeves mounted on different truss components are connected to one another with a length-adjustable shank. The stiffener may be used in two-dimensional or three-dimensional trusses. Of a collection of prefabricated trusses necessary to erect a structure, only a subset of one or more trusses are customized with stiffeners according to loading calculations predicting failure of that subset under required loading conditions, while all other trusses are installed in their original prefabricated state.

Abstract: Although Fiber Reinforced Polymers (FRPs), as alternatives for the corrosive steel reinforcement in concrete structures, have shown promising performance under gravity loads, their performance under reversal cyclic loading is still one of the main concerns. The linear behavior of FRP reinforcement has a two-sided effect on the seismic performance of FRP-reinforced concrete (RC) moment-resisting frames. Although the linear nature of FRP reinforcement could be advantageous in terms of limiting the residual damage after an earthquake event, it lowers the energy dissipation of the structure which can compromise its seismic performance. Disclosed herein is the addition of steel plates at selected locations in moment-resisting frames to improve seismic performance of FRP-RC structures while still being able to take advantage of its linear behaviour (minimal residual damage after earthquake). The effectiveness of the proposed solution was tested both experimentally and analytically.

Abstract: A length-adjustable truss stiffener is intended to be used to strengthen truss systems at locations of localized over-stress to reduce the cost from the alternative solution which is to reduce truss spacings. The stiffener consists of two or more sleeves locking around two or more components of the main truss. The sleeves mounted on different truss components are connected to one another with a length-adjustable shank. The stiffener may be used in two-dimensional or three-dimensional trusses. Of a collection of prefabricated trusses necessary to erect a structure, only a subset of one or more trusses are customized with stiffeners according to loading calculations predicting failure of that subset under required loading conditions, while all other trusses are installed in their original prefabricated state.