Moment-Curvature Behaviors of Concrete Beams Singly Reinforced by Steel-FRP Composite Bars

Abstract

A steel-fiber-reinforced polymer (FRP) composite bar (SFCB) is a kind of rebar with inner steel bar wrapped by FRP, which can achieve a better anticorrosion performance than that of ordinary steel bar. The high ultimate strength of FRP can also provide a significant increase in load bearing capacity. Based on the adequate simulation of the load-displacement behaviors of concrete beams reinforced by SFCBs, a parametric analysis of the moment-curvature behaviors of concrete beams that are singly reinforced by SFCB was conducted. The critical reinforcement ratio for differentiating the beam's failure mode was presented, and the concept of the maximum possible peak curvature (MPPC) was proposed. After the ultimate curvature reached MPPC, it decreased with an increase in the postyield stiffness ratio ( sf ), and the theoretical calculation method about the curvatures before and after the MPPC was derived. The influence of the reinforcement ratio, effective depth, and FRP ultimate strain on the ultimate point was studied by the dimensionless moment and curvature. By calculating the envelope area under the moment-curvature curve, the energy ductility index can obtain a balance between the bearing capacity and the deformation ability. This paper can provide a reference for the design of concrete beams that are reinforced by SFCB or hybrid steel bar/FRP bar.

Experimental and Numerical Investigation on Carbon Fiber‐Reinforced Polymer‐Strengthened Concrete Beam after High‐Temperature Action of Asphalt Paving Construction

“…Due to its special material properties, it has shown good ability in improving structural load-carrying capacity. Many researchers studied the performance of the CFRP-strengthened structures [1][2][3][4][5]. Structural performance of the fiberreinforced polymer-(FRP-) concrete composite bridge deck was studied experimentally and numerically by Tian et al [1].…”

Seismic responses of postyield hardening single–degree‐of‐freedom systems incorporating high‐strength elastic material

“…While structures made of conventional materials may exhibit some postyield stiffness (usually less than 10% of the initial stiffness), the application of new materials with high strength and superior elastic properties can easily be used to develop structures with a much higher and more stable postyield stiffness. These high‐strength elastic materials, such as fiber‐reinforced polymer (FRP) and high‐strength steel bars, exhibit little or approximately no plastic behavior and have been recently used to fabricate many novel materials, members, and structures. Compared with the components made of only conventional materials (steel and concrete), increasingly more materials, members, and structures that incorporate both high‐strength elastic materials and conventional materials show significant postyield hardening (PYH) skeleton curves (Figure ).…”

“…Compared with the components made of only conventional materials (steel and concrete), increasingly more materials, members, and structures that incorporate both high‐strength elastic materials and conventional materials show significant postyield hardening (PYH) skeleton curves (Figure ). A variety of such innovative components are summarized in Table (references cited in Table ). These materials, members, and structures can be called PYH materials, members, and structures, respectively.…”

Equivalent Frame Model with a Decaying Nonlinear Moment-Curvature of Steel-Reinforced Concrete Joints

“…Recent articles have attempted to simulate the decreasing plastic behavior until breakage of reinforced concrete structures using moment-curvature graphs [21].…”