The adequacy of using Fiber Reinforced Polymer (FRP) retrofit technique to restore the flexure-compression behavior of deteriorated bridge timber piles is examined experimentally in this paper. Sixteen specimens are t...The adequacy of using Fiber Reinforced Polymer (FRP) retrofit technique to restore the flexure-compression behavior of deteriorated bridge timber piles is examined experimentally in this paper. Sixteen specimens are tested monotonically under eccentric compressive loading. The specimens are first tested in their unretrofitted condition to determine their elastic properties. Each specimen is then cut and connected (posted) using the proposed FRP retrofit technique, and retested. The results show that the retrofitted specimens are capable of reaching same or higher strengths than that of the unretrofitted specimens with minimal reduction in their stiffness. Based on the experimental results, a design equation is presented to compute the volumetric ratio of FRP needed for retrofitting bridge timber piles under eccentric load.展开更多
The most critical drawback in currently used steel reinforcement in reinforced concrete(RC)structures is susceptibility to accumulation of plastic deformation under excessive loads.Many concrete structures due to dama...The most critical drawback in currently used steel reinforcement in reinforced concrete(RC)structures is susceptibility to accumulation of plastic deformation under excessive loads.Many concrete structures due to damaged(yielded)steel reinforcement have undergone costly repairs and replacements.This research presents a new type of shape memory alloy(SMA)-based composite reinforcement with ability to withstand high elongation while exhibiting pseudoelastic behavior.In this study,small diameter SMA wires are embedded in thermoset resin matrix with or without additional glass fibers to develop composite reinforcement.Manufacturing technique of new proposed composite is validated using microscopy images.The proposed SMA-FRP composite square rebars are first fabricated and then embedded in small scale concrete T-beam.3-point bending test is conducted on manufactured RC beam using a cyclic displacement controlled regime until failure.It is found that the SMA-FRP composite reinforcement is able to enhance the performance of concrete member by providing re-centering and crack closing capability.展开更多
文摘The adequacy of using Fiber Reinforced Polymer (FRP) retrofit technique to restore the flexure-compression behavior of deteriorated bridge timber piles is examined experimentally in this paper. Sixteen specimens are tested monotonically under eccentric compressive loading. The specimens are first tested in their unretrofitted condition to determine their elastic properties. Each specimen is then cut and connected (posted) using the proposed FRP retrofit technique, and retested. The results show that the retrofitted specimens are capable of reaching same or higher strengths than that of the unretrofitted specimens with minimal reduction in their stiffness. Based on the experimental results, a design equation is presented to compute the volumetric ratio of FRP needed for retrofitting bridge timber piles under eccentric load.
文摘The most critical drawback in currently used steel reinforcement in reinforced concrete(RC)structures is susceptibility to accumulation of plastic deformation under excessive loads.Many concrete structures due to damaged(yielded)steel reinforcement have undergone costly repairs and replacements.This research presents a new type of shape memory alloy(SMA)-based composite reinforcement with ability to withstand high elongation while exhibiting pseudoelastic behavior.In this study,small diameter SMA wires are embedded in thermoset resin matrix with or without additional glass fibers to develop composite reinforcement.Manufacturing technique of new proposed composite is validated using microscopy images.The proposed SMA-FRP composite square rebars are first fabricated and then embedded in small scale concrete T-beam.3-point bending test is conducted on manufactured RC beam using a cyclic displacement controlled regime until failure.It is found that the SMA-FRP composite reinforcement is able to enhance the performance of concrete member by providing re-centering and crack closing capability.
