Experiment of flexural behavior of an existing RC beam reinforced by selfcompacting concrete under different continuous loading(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年04期
- Page:
- 62-72
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Experiment of flexural behavior of an existing RC beam reinforced by selfcompacting concrete under different continuous loading
- Author(s):
- ZHANG Jianren1; LUO Yuming1; 2; ZHANG Xuhui1; 3; PENG Jianxin
- (1. School of Civil Engineering, Changsha University of Science and Technology, Changsha 410114, Hunan, China； 2. School of Road and Bridge Engineering, Hunan Communication Polytechnic, Changsha 410132, Hunan, China;〖JP〗 3. College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105, Hunan, China)
- Keywords:
- bridge engineering; selfcompacting concrete; RC beam reinforcement; experimental study; continuous load; flexural behavior
- PACS:
- -
- DOI:
- -
- Abstract:
- To investigate the effects of initial damage and sustained load on the flexural behavior of structures strengthened using the enlarge section method with selfcompacting concrete, eight reinforcement concrete T beams were designed and constructed. These beams were first loaded to simulate the initial damage. Then, they were strengthened using the enlarge section method with selfcompacting concrete under different sustained loads. Thereafter, the beams were tested under a flexural load to investigate the effects of sustained load and the strengthening thickness below the T beams on the flexural capacity and the section stiffness of the strengthened reinforced concrete beams. The crack distributions, failure modes, loaddeflection curves and concrete strain developments were assessed in the test study. Finally, a method is discussed based on the experimental test for flexural capacity prediction of the strengthened structures. The results show that the used reinforcement method of selfcompacting concrete significantly increases the beam section stiffness. The beam flexural capacity increases approximately one time and nearly all the reinforced beams show the expected ductile failures. The flexural capacity of the beams somewhat increases with an increase in the thickness of the selfcompacting concrete below the beams. The increase in the flexural capacity, however, is slow compared to the weight increase of the strengthened members. The low continuous load during the reinforcement procedure has little effect on beam flexural capacity degradation, which can slightly increase the flexural capacity. The high continuous load, however, deteriorates the beam flexural capacity. The effects of continuous load on beam section stiffness also depends on the condition of the initial cracks on the beam surface. For the beams with the closed initial cracks on the surface, a certain degree of continuous load can increase the beam section stiffness. A high continuous load can lead to the opening of initial cracks during the reinforcement procedure, which results in the degradation of the beam section stiffness. For beams strengthened with appropriate steel reinforcement, it is feasible to predict the beam flexural capacity based on the plastic limit analysis method and neglecting the strainlag effects caused by the sustained load during the strengthening process. 2 tabs, 10 figs, 25 refs.
Last Update: 2019-07-29