Behavior of reinforced concrete beams strengthened with externally bonded hybrid fiber reinforced polymer systems

Relationships between interfacial shear stresses and moment capacities of RC beams strengthened with various types of FRP sheets

“…Moreover, relatively few studies have suggested relations between the interfacial stresses and moment capacity of beams strengthened with taper-layered FRP sheets. Hawileh et al [26] investigate load carrying capacities of RC beams strengthened with different combinations of hybrid GFRP and CFRP sheets and compare the experimental results with available design guidelines. According to the study, load carrying capacities predicted by ACI 440 show good agreements with the experimental results in the case of the beams strengthened with non-hybrid FRP, while conservative results are predicted by the design guidelines when hybrid FRPs are used.…”

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

“…In the case of RC members externally reinforced with FRP, not all such initial cracks are stable under service conditions, since bond stresses may cause the cracks to propagate [4,6,9,13,27,31,35,37,39]. This research work was devoted to discovering those that are liable to propagate, causing debonding of external reinforcement, and to predict the time required.…”

“…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]. Unfortunately, neither the structural codes nor the structural practice considers explicitly the service failure that is caused by slow crack growth in the concrete cover.…”

Preparation and properties of novel building materials at low temperature

“…improve binding force between fiber. Furthermore, for instance, gel-modified concrete [12][13][14][15] could also enhance mechanical strength of concrete dramatically. Thus, gel was selected and added into Pykrete and New Pykrete, respectively.…”