Experimental study of retrofitted reinforced concrete shear wall and concrete-encased steel girders using a new CarbonFlex composite for damage stabilization

Crashworthiness characteristics of a carbon fiber reinforced dual-phase epoxy–polyurea hybrid matrix composite

“…In many crashworthy applications, such as those applicable to the automotive industry, energy absorption capability may not be the only concern since cost and durability also play a substantial role. In an attempt to develop more cost efficient and durable composite materials with increased damage tolerance, a polymeric matrix composite (PMC) that was recently developed by some of the authors [15][16][17][18][19] has been experimentally tested herein, in order to determine the energy absorption and crashworthiness characteristics of the material. This PMC is referred to as Carbon-fiber reinforced Hybrid Matrix Composite, or CHMC [20], consisting of high strength carbon fibers and a dual-phase hybridized matrix composed of Bisphenal A (BPA) epoxy and an amino-based cross-linked polymer to formulate a polyurea compound that ultimately helps provide high damping, fracture toughness, and superior strength sustainability.…”

Analytical model to predict the lifetime of concrete members externally reinforced with FRP

“…In brittle materials there are three regimes of crack growth as K II varies from 0 to its critical value K IIC . Consequently, the relationship between da/dt and K II /K IIC exhibits three different trends [22,23,25,31,36,[44][45][46][47].…”

“…According to fracture mechanics of brittle materials, the velocity da/dt (t denotes the time) at which the crack propagates in a given concrete depends on the ratio between K II and K IIC only [4,6,9,[18][19][20]25,29,34,35,[40][41][42]. In brittle materials there are three regimes of crack growth as K II varies from 0 to its critical value K IIC .…”

“…Unfortunately, practice often extends this property from the separate and standalone FRP-composite material to the entire FRP-strengthened system. However, durability of a RC member externally reinforced with FRP depends not only on durability of the individual materials, but also on the capacity of the concrete cover to sustain the bond stresses s b [22][23][24][25]. In fact, on one hand, the FRP-composite material keeps its original strength, elasticity, and toughness [5,13,15,16,[26][27][28]; on the other hand, however, the combination of s b and initial cracks (flaws) in the concrete cover may give rise to slow crack growth up to the critical length, and eventually to debonding of the external reinforcement [29][30][31][32][33][34][35][36].…”

Research on Calculation Methods for Ductility of RC Beams with Near-Surface Mounted CFRP Plate Reinforcement

“…The result of the experiments indicated that the above method can improve the ductility of the members, but decrease the bending stiffness and strength of beams. Zhou and Attard (2012) and Zhou et al (2013) used carbon fiber-epoxy polyurea composite, combining with a polyphase hybridized interface, to avoid the dissipation of energy to achieve sustainable high strength and increase the ductility of the concrete. The proposed method was validated by experiments, but has a drawback of this method is not applicable in the NSW FRP strengthened system.…”