FRP stay-in-place form and shear key connection for FRP-concrete hybrid beams/decks

Experimental Investigation of the Natural Bonding Strength between Stay-In-Place Form and Concrete in FRP-Concrete Decks/Beams

“…Similar to steel-concrete composite decks and beams, a FRP-concrete hybrid deck/beam needs strong composite action to obtain a high structural performance. Additionally, it has been revealed that strong composite action between FRP and concrete can maximize the use of the tensile strength of FRP and compressive strength of concrete [29][30][31]. Therefore, the shear connection along the FRP-concrete interface has been a research topic that has attracted more attention since 1994 [32][33][34][35].…”

“…More importantly, after taking into account the lower cost of transportation, easier installation, and low or even no maintenance cost, the high initial cost of FRP can be compensated, which makes the hybrid system more competitive in the market for decks of different spans and girders for short span bridges [25][26][27][28].Similar to steel-concrete composite decks and beams, a FRP-concrete hybrid deck/beam needs strong composite action to obtain a high structural performance. Additionally, it has been revealed that strong composite action between FRP and concrete can maximize the use of the tensile strength of FRP and compressive strength of concrete [29][30][31]. Therefore, the shear connection along the FRP-concrete interface has been a research topic that has attracted more attention since 1994 [32][33][34][35].…”

“…Therefore, the shear connection along the FRP-concrete interface has been a research topic that has attracted more attention since 1994 [32][33][34][35]. A simple way to improve the connection capacity and reduce the slip is to use strong and stiff connections such as polymeric adhesives [20], coated sands on FRP profiles [20], perforated FRP ribs [25,32], and FRP shear keys [29,34]. However, since FRP cannot be welded easily like steel, FRP-concrete interfacial connections usually have a lower shear capacity and slip modulus when compared with the connections in steel-concrete hybrid components [25,[29][30][31][35][36][37][38].…”

“…A simple way to improve the connection capacity and reduce the slip is to use strong and stiff connections such as polymeric adhesives [20], coated sands on FRP profiles [20], perforated FRP ribs [25,32], and FRP shear keys [29,34]. However, since FRP cannot be welded easily like steel, FRP-concrete interfacial connections usually have a lower shear capacity and slip modulus when compared with the connections in steel-concrete hybrid components [25,[29][30][31][35][36][37][38]. The connection types, for example, steel studs, perfobond ribs, and channel plates, in steel-composite decks and beams cannot be directly used for FRP-concrete hybrid decks/beams as the interfacial slip can cause notable flexural rigidity degradation and normal stresses increase at the FRP and concrete parts.…”

Initial crack effect on the strength of oblique cross sections of reinforced concrete beams strengthened with carbon fiber

“…For example, now, the effect of the shear span on the behavior of oblique cross sections reinforced with composite U stirrups [9] is being actively studied. Software design systems based on neural networks [10] are developed; and the computational tool for the RC structures strengthened with composite materials presented in existing regulatory documents is updated [11][12][13][14][15]. The release of the Code of Rules SP 164.1325800.2014, 2014, dedicated to the strengthening of reinforced concrete structures with composite materials, gave an additional incentive to conduct scientific research in this field, but did not solve all the problems.…”