Abstract
The difficulties induced from high-durability package, large-scale measurement, and sensor installation make it a big challenge but an urgent need to predict the mechanical behavior of strengthened reinforced concrete structure with the externally bonded fiber-reinforced polymer (FRP) plate under harsh environments and rough construction process. In an effort to solve this challenge, this paper proposes a novel end anchored self-sensing CFRP plate assembly with built-in optical fiber Bragg grating (FBG) sensor. The self-sensing principle is presented and a demonstration test was carried out in the laboratory in order to investigate the self-sensing properties of the intelligent CFRP plate. Three-point flexural tests of a total of ten RC beams were carried on: six strengthened with the bonded or unbonded posttensioned intelligent CFRP plates, one strengthened with the ordinary CFRP plate, and three strengthened with the control beams. The full-range CFRP plate strain at the maximum moment was measured utilizing the FBG interrogator. Using this monitoring data, the short-term prestress loss attributed to anchorage set and the relationship between the external load and the CFRP strain at the middle span associated with the integral response of the strengthened member were investigated. Besides, the objective of the tests was also to gain a better understanding of the failure mode and the flexural behavior of RC beams strengthened with posttensioned CFRP plates taking into account the different strengthening methods, initial damage, and the dead load before strengthening. The experimental results showed that the developed CFRP plate with built-in FBG sensors not only can be the reinforcement of the RC structures, but also provide an effective way to monitor the full-range behavior of the CFRP plate with the excellent self-sensing property shown in the demonstration tests.
Highlights
From the mid-1980s and continuing to the present time, a vast number of concrete, metallic, and masonry structures were/ are in urgent need of repair/strengthening/rehabilitation, due to either a change in use or structural degradation
This paper presents a novel durable intelligent carbon fiber-reinforced polymer (CFRP) plate strain monitoring assembly with end anchorages using fiber Bragg grating (FBG) sensors, and the associated experimental study on the posttensioned CFRP strengthening of reinforced concrete (RC) beams was carried out
The CFRP plate with built-in FBG sensor can monitor the axial strain at stress hot spot with high accuracies under each loading step in the prestressing application stage and short-term prestress loss stage
Summary
From the mid-1980s and continuing to the present time, a vast number of concrete, metallic, and masonry structures were/ are in urgent need of repair/strengthening/rehabilitation, due to either a change in use or structural degradation. The strain monitoring of the posttensioned FRP strengthening system under different prestressing techniques in the whole loading history is prime pursued to understand the behavior of the CFRP plates in field application and validate the suitability of prestressed CFRP in the strengthening of RC beams and further predict the real-time bending resistance of the RC member based on the monitoring data at the control section for the safety assessment of the strengthened structures. The above researches have generally verified the excellent performance of FBG sensors in the strain monitoring of FRP composites Against this background, this paper presents a novel durable intelligent CFRP plate strain monitoring assembly with end anchorages using FBG sensors, and the associated experimental study on the posttensioned CFRP strengthening of RC beams was carried out. The experimental arrangement included a demonstration test for its self-sensing properties as well as the posttensioned CFRP strengthening of RC beams under different conditions (e.g., strengthening methods, loading history, and initial damage) to achieve a clear understanding of the behavior of the strengthening system and the strain monitoring system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
