Cracking behavior of geopolymer concrete beams reinforced with steel and fiber reinforced polymer bars under flexural load. (1st April 2020)

• Record Type: Journal Article
• Authors: Rashid, Khuram; Li, Xiaoda; Xie, Yan; Deng, Jun; Zhang, Faji
• Is Part Of: Composites. Number 186(2020)
• Publication Date: 2020-04-01
• Subjects: RC beam -- FRP bars -- Flexural behavior -- Crack spacing -- Bond strength; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2020.107777
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: The cracking pattern and spacing in reinforced concrete (RC) structures considerably influence structural performance. Cracking may be severe with the utilization of fiber reinforced polymer (FRP) bars as compared to steel due to its low modulus of elasticity. In this study, the crack initiation, propagation and spacing, failure mode and ultimate load of RC beams reinforced with steel, basalt FRP (BFRP) and carbon FRP (CFRP) were investigated. A four-point bending test was conducted on fifteen RC beams. The beams with FRP bars exhibited worse cracking resistance and faster propagation throughout the loading process than those including steel bars. The cracking pattern was associated with failure modes from flexural to flexural-shear failure, which ultimately influenced the failure load. Furthermore, the crack spacing was analytically evaluated by three models used in conventional RC structures. The results showed that incorporating the rebar-concrete bond strength in Zhang's model resulted in more precise analytical values. Then, the bond strengths of all the FRP-concrete beams were evaluated by four codes. A strong correlation between the analytical and experimental crack spacing values was observed when considering code Canadian Standard Association (CSA) S806-12, and a significant margin of safety was obtained when considering the Japanese Society of Civil Engineering (JSCE) code.