Research on bond–slip performance between pultruded glass fiber-reinforced polymer tube and nano-CaCO3 concrete

AbstractThe article describes an experimental study on the bond–slip performance between the pultruded glass fiber-reinforced polymer (GFRP) tube and the nano-CaCO3 concrete. Taking the nano-CaCO3 concrete strength and GFRP tube thickness as primary parameters, nine specimens were designed and tested to study the influence of these parameters on the bond strength of the specimens. Besides, three specimens filled with the ordinary concrete were also tested by using the push-out tests to make comparisons with the bond performance of the specimens filled with nano-CaCO3 concrete. A total of four push-out tests were conducted on each specimen. The experimental results indicate that there are two types of axial load–slip curves for each specimen in four push-out tests. Moreover, comparison of the results of the push-out tests in the same direction shows that the bond failure load of the specimen decreases with the increase in the number of push-out tests. Based on the analysis of the test results, it is shown that the bond performance between the GFRP tube and the nano-CaCO3 concrete is better than that between the GFRP tube and the ordinary concrete. Furthermore, as the nano-CaCO3 concrete strength increases, the bond strength of the specimens decreases, indicating that the concrete strength has a negative effect on the bond strength. When the nano-CaCO3 concrete strength is relatively smaller (C20), the bond strength of the specimens decreases with the increase in the thickness of the GFRP tube. However, when the nano-CaCO3 concrete strength is relatively larger (C30 and C40), the bond strength of the specimens increases as the thickness of the GFRP tube increases.

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Bond performance of GFRP and deformed steel hybrid bar with sand coating to concrete

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684416684209 ◽

2016 ◽

Vol 36 (6) ◽

pp. 464-475 ◽

Cited By ~ 3

Author(s):

Minkwan Ju ◽

Gitae Park ◽

Sangyun Lee ◽

Cheolwoo Park

Keyword(s):

Glass Fiber ◽

Modulus Of Elasticity ◽

Fiber Reinforced Polymer ◽

Fiber Reinforced ◽

Glass Fiber Reinforced Polymer ◽

Bond Performance ◽

Polymer Hybrid ◽

Reinforced Polymer ◽

Glass Fiber Reinforced ◽

Steel Bar

In this study, we experimentally investigated the bond performance of a glass fiber-reinforced polymer hybrid bar with a core section comprising a deformed steel bar and a sand coating. The glass fiber-reinforced polymer and deformed steel hybrid bar (glass fiber-reinforced polymer hybrid bar) can contribute to longer durability and better serviceability of reinforced concrete members because of the increased modulus of elasticity provided by the deformed steel bar. Uniaxial tensile tests in compliance with ASTM D 3916 showed that the modulus of elasticity of the glass fiber-reinforced polymer hybrid bar was enhanced up to three times. For the bond test, a total of 30 specimens with various sand-coating and surface design parameters such as the size of the sand particles (0.6 mm and 0.3 mm), sand-coating type (partially or completely), number of strands of fiber ribs (6 and 10), and pitch space (11.4 mm to 29.1 mm) of the fiber ribs were tested. The completely sand-coated glass fiber-reinforced polymer hybrid bar exhibited a higher bond strength (90.5%) than the deformed steel bar and a reasonable mode of failure in concrete splitting. A modification parameter to the Eligehausen, Popov, and Bertero (BPE) model is suggested based on the representative experimental tests. The bond stress–slip behavior suggested by the modified BPE model in this study was in reasonable agreement with the experimental results.

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Utilizing alkali-activated materials as ordinary Portland cement replacement to study the bond performance of fiber-reinforced polymer bars in seawater sea-sand concrete

Advances in Structural Engineering ◽

10.1177/13694332211065186 ◽

2022 ◽

pp. 136943322110651

Author(s):

Ruiming Cao ◽

Bai Zhang ◽

Luming Wang ◽

Jianming Ding ◽

Xianhua Chen

Keyword(s):

Tensile Strength ◽

Bond Strength ◽

Ordinary Portland Cement ◽

Concrete Strength ◽

Fiber Reinforced Polymer ◽

Bond Performance ◽

Reinforced Polymer ◽

Sea Sand ◽

Frp Bars ◽

Alkali Activated

Alkali-activated materials (AAMs) are considered an eco-friendly alternative to ordinary Portland cement (OPC) for mitigating greenhouse-gas emissions and enabling efficient waste recycling. In this paper, an innovative seawater sea-sand concrete (SWSSC), that is, seawater sea-sand alkali-activated concrete (SWSSAAC), was developed using AAMs instead of OPC to explore the application of marine resources and to improve the durability of conventional SWSSC structures. Then, three types of fiber-reinforced polymer (FRP) bars, that is, basalt-FRP, glass-FRP, and carbon-FRP bars, were selected to investigate their bond behavior with SWSSAAC at different alkaline dosages (3%, 4%, and 6% Na2O contents). The experimental results manifested that the utilization of the alkali-activated binders can increase the splitting tensile strength ( ft) of the concrete due to the denser microstructures of AAMs than OPC pastes. This improved characteristic was helpful in enhancing the bond performance of FRP bars, especially the slope of bond-slip curves in the ascending section (i.e., bond stiffness). Approximately three times enhancement in terms of the initial bond rigidity was achieved with SWSSAAC compared to SWSSC at the same concrete strength. Furthermore, compared with the BFRP and GFRP bars, the specimens reinforced with the CFRP bars experienced higher bond strength and bond rigidity due to their relatively high tensile strength and elastic modulus. Additionally, significant improvements in initial bond stiffness and bond strength were also observed as the alkaline contents (i.e., concrete strength) of the SWSSAAC were aggrandized, demonstrating the integration of the FRP bars and SWSSAAC is achievable, which contributes to an innovative channel for the development of SWSSC pavements or structures.

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Evaluation of the Bond-to-Concrete Properties of GFRP Rebars in Marine Environments

Infrastructures ◽

10.3390/infrastructures3040044 ◽

2018 ◽

Vol 3 (4) ◽

pp. 44 ◽

Cited By ~ 1

Author(s):

Alvaro Ruiz Emparanza ◽

Francisco De Caso Y Basalo ◽

Raphael Kampmann ◽

Itziar Adarraga Usabiaga

Keyword(s):

Bond Strength ◽

Concrete Structures ◽

Steel Reinforcement ◽

Fiber Reinforced Polymer ◽

Multiple Time ◽

Bond Performance ◽

Reinforced Polymer ◽

Glass Fiber Reinforced ◽

Different Temperatures ◽

Corrosion Of Steel

Increased traffic in combination with growing environmental impacts have led to the accelerated degradation of built infrastructure. In reinforced concrete structures, the corrosion of steel reinforcement is the predominant cause of deterioration. Thus, over the last years the use of glass fiber reinforced polymer (GFRP) composites as internal reinforcement bars (rebars) for concrete structures has been evaluated, and has been proved to be a viable alternative to traditional steel reinforcement mainly due to its tensile strength and non-corrosive nature. However, thus far, the GFRP rebar market is diverse and manufacturers around the world produce GFRP rebar types with different surface enhancements to improve the bond to concrete characteristics. In this study, the bond performance of three dissimilar GFRP rebar types (sand coated, helically grooved and with surface lugs) was evaluated over time in seawater environments, with a focus on the bond strength. Accordingly, specimens were exposed to seawater in circulating chambers at three different temperatures (23 °C, 40 °C and 60 °C) for multiple time periods (60 and 120 days). To evaluate the bond performance, pullout tests were conducted according to ASTM D7913. The results showed that the bond strength varied with the surface enhancement features. However, the bond strength did not vary significantly with exposure time and temperature for all three evaluated rebar types.

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