مکانیسم آسیب ساختاری تیرهای بتنی
Abstract
Graphical abstract
1. Introduction
2. Principle of monitoring flexural behavior of beams using SA transducer based on time reversal method
3. Experimental setup and procedure
4. Experimental results discussion
5. Discussion
6. Conclusions
Author contributions
Declaration of Competing Interest
Acknowledgements
References
Abstract
Fiber reinforced polymer (FRP) bars, as alternatives of steel bars, are encouraged to be utilized in concrete construction due to the properties of both corrosion resistance and high tensile strength. In this paper, smart aggregate (SA) transducers, which can be used as both actuator and sensor, are employed to identify the structural damage mechanism of basalt-FRP (BFRP) bars reinforced concrete beams. Time reversal method is adopted for increasing the signal-to-noise ratio (SNR), which is aimed at obtaining clear amplitude of focused signal. Those methodologies are applied to conduct a further study of the structural mechanism of BFRP reinforced concrete flexural components. The experimental results reveal that the cracking and failure position of the concrete beam reinforced with BFRP bars can be located and the corresponding loads can be identified according to signal change when different crack appears. The stiffness degradation of BFRP bars reinforced concrete beams can be effectively expressed and the deflection can be accurately predicted by acquiring amplitude of focused signals in the overall zone. Additionally, it has been recognized that the damage process and mechanism of BFRP reinforced concrete beams can be accurately evaluated using those SA transducers and the status of those structural components also can be monitored effectively.
Introduction
It is well-founded that the corrosion of steel reinforcement and fatigue damage lead to degradation of concrete structural performance [1–4]. Therefore, the reduced durability and shortened service life are exposed in this structural component [5]. For existing damaged structures, the repair using fiber reinforced polymer (FRP) materials in the form of fabrics and laminates can retrofit these corrosion-damaged and fatigue-damaged concrete structural [6–11]. In the new-built structures, a new-type of reinforcement, FRP bar, as a substitute for steel bar is encouraged to use in concrete structures owing to its advantages of excellent mechanical properties and corrosion resistance properties [12–۱۶]. Some concrete bridge structures have been constructed with FRP bars, such as the Thompson’s Bridge, Mackinleyville Bridge and Talyor Bridge [17]. Zheng et al. [15,18] revealed that basalt-FRP (BFRP) reinforced self-compacting concrete (SCC) deck slabs exhibited good structural behaviors within the service load. Ehab El-Salakawy et al. [19] conducted a field investigation on the bridge deck slab reinforced with glass-FRP (GFRP) bars constructed in Canada, and results revealed that GFRP rebar provided very competitive performance in comparison to steel under actual service conditions.