Experimental Study on Seismic Performance of CFRP Strengthened RC Frames Damaged by Earthquake

2013 ◽  
Vol 724-725 ◽  
pp. 1749-1753
Author(s):  
Qiu Mei Gao ◽  
Lai Wang ◽  
Ying Zhang

In this paper, we carried out low cyclic loading test over CFRP strengthened seismic-damaged RC frame named KJ-2 with the quasi-static test method, and compared the seismic performance with the same sections and materials RC frame named KJ-1 which was unstrengthened. We study the seismic performance such as hysteresis curve, skeleton curve, stiffness degradation, bearing capacity degeneration, displacement ductility, and energy dissipation capacity of the reinforced RC frame. On this basis, we analyzed the results of this test in order to obtain some guiding opinions for asymmetric span RC frames that strengthened by CFRP, and provide main preference basis or future national or industry standards.

2014 ◽  
Vol 578-579 ◽  
pp. 252-255
Author(s):  
Ya Feng Xu ◽  
Qian Chen ◽  
Pi Yuan Xu ◽  
Riyad S. Aboutaha

Composite concrete filled steel tubular (CFST) column is a new type of column having high ductility and high load-bearing capacity. In this paper, the finite element analysis software ABAQUS is used to study the seismic performance of 3D joint of composite CFST column and steel beam. The hysteretic curve and skeleton curve are obtained by changing the strength grade of the steel beam; calculate the energy dissipation ratio of the joint. The results show that the higher the beam’s steel strength the higher ultimate capacity of the joint in the constant axial load. But the full degree of hysteresis curve, energy dissipation and displacement ductility of the space joint decrease.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Lai Wang ◽  
Wei Xuan ◽  
Ying Zhang ◽  
Shuping Cong ◽  
Feng Liu ◽  
...  

In order to assess the seismic performance of damaged reinforced concrete (RC) frame strengthened with carbon fiber reinforced polymers (CFRP) sheets, two experimental specimens with identical reinforcement ratio and geometric dimensions were designed following Chinese code for seismic design of buildings. Experimental specimens consist of a reference (undamaged) RC frame, namely, KJ-1, and an earthquake-damaged RC frame strengthened with CFRP sheets, namely, KJ-2. A pseudostatic test was conducted on the two specimens to simulate moderate earthquake damage. The strengthening effects of CFRP sheets on damaged RC frame were discussed in terms of hysteretic curve, skeleton curve, stiffness degradation, and ductility. In addition, numerical method based on fiber model method was utilized to analyze the seismic performance of KJ-1 and KJ-2 and it is compared with the experimental result. Both the results confirm that the method of exterior bonding CFRP sheets on the damaged RC frame has restored the seismic performance such as bearing capacity, stiffness, and ductility to its original undamaged level, and some of the seismic performance of the damaged RC frame strengthened with CFRP sheets is even better than the undamaged one, which proves that the method has significant effect in strengthening postearthquake-damaged RC frames.


2011 ◽  
Vol 94-96 ◽  
pp. 464-468
Author(s):  
Fei Wang ◽  
Zhi Fang ◽  
Xin Feng Yin

Designing the reasonable cross-section and the structural conformation, three Reactive power concrete box piers samples were designed and studied under the constant axial force and reversed horizontal loads. The effect of the reversed horizontal load on the seismic performance of RPC box pier was studied. Such seismic performance as ductility, hysteresis curve, skeleton curve, etc. of RPC box piers is studied by pseudo-static test on three RPC box piers. The simulation results shows that RPC box piers exists excellent performance of resisting seismic force, the direction of horizontal load significant affect that performance, and the performance of resisting seismic force for the pier loaded by the force from main axial direction are better than that from other direction.


2021 ◽  
pp. 136943322199772
Author(s):  
Shao-Ge Cheng ◽  
Yi-Xiu Zhu ◽  
Wei-Ping Zhang

This study presents the shake-table tests of a 1/5-scaled RC frame retrofitted with RC infill walls. The intensity of input ground motions increased gradually to comprehensively evaluate the structural seismic behavior. We performed a comparison of the results from the RC frame with masonry walls and that with RC walls. The results showed that the presence of RC infills effectively improved the lateral structural stiffness and loading capacity of the frames and reduced their damage and story drift. RC walls acted as the first seismic line of defense, and their failure was dominated by bending failure and concentrated on the low stories. The displacement ductility of the structure decreased with increasing stiffness of the introducing infills.


2013 ◽  
Vol 717 ◽  
pp. 277-282
Author(s):  
Jin Chen ◽  
Shi Yong Jiang ◽  
Zhi Kun Lin ◽  
Ying Tao Li ◽  
Xiang Rong Zeng ◽  
...  

Through pseudo static test on three pieces of fiber reinforced plastics (FRP) transfer beam supported frame with three different reinforcement form, reinforcement ratio and the number of root reinforcement ,which are subjected to the vertical load and horizontal low cycle reciprocating load, the specimen fracture development law, yield mechanism, failure pattern, and bearing capacity, ductility, hysteresis characteristics and seismic performance are analyzed. The test results show that: yield mechanism and failure pattern of transfer beam supported frame equipped with fiber reinforced plastics reinforced bars are reasonable. The bearing capacity and deformation performance of transfer beam supported frame with top and bottom longitudinal bar replaced by FRP bars and symmetrical reinforced box are better than that of single upper replacement for FRP and lower replacement for FRP. The ductility performance of transfer beam supported frame equipped with fiber reinforced plastics bars is good, hysteresis curve is full, and have good seismic performance.


2017 ◽  
Vol 2017 ◽  
pp. 1-14
Author(s):  
Yingchao Ma ◽  
Jinqing Jia

The seismic behaviors of steel reinforced ultrahigh strength concrete (SRUHSC) frames with different axial compression ratios and shear span ratios are experimentally studied through the reversed cyclic loading test of four specimens. The test results reveal that the seismic response of the frame is closely related to the failure process and failure mode of the columns. Based on the results, a systematic exploration is further conducted in terms of the characteristics of the skeleton curve, hysteresis curve, strength degradation, stiffness degradation, and energy dissipation capacity of the structure. The results indicate that as the axial compression ratio increases, and the shear span ratio decreases, the failure process of the entire structure and the weakening of the beam end are accelerated. Meanwhile, a change of the failure mode is also observed, accompanied by corresponding changes in the strength, stiffness, and energy dissipation capacity of the system.


2011 ◽  
Vol 50-51 ◽  
pp. 1003-1007 ◽  
Author(s):  
Jian Qiang Han ◽  
Zhen Bao Li ◽  
Xiao Sheng Song

This thesis studies deeply the crack development characteristics, failure pattern, hysteresis curve and the displacement ductility of this new prestressed precast reinforced concrete intelligent structure, by analyzing one prestressed precast reinforced concrete frame under low reversed cyclic load test. Prestressed precast reinforced concrete frame is a new assembly architecture intelligent structure. We build a model using finite element analysis software to the test piece model analysis, the analysis result agree well with the experimental results. Experimental studies indicate that this new prestressed precast reinforced concrete intelligent structure has a good seismic performance. This prestressed precast reinforced concrete frame is a new kind of structural system complying with the development of architectural industrialization, which is worthy of popularization and application in the earthquake area.


2011 ◽  
Vol 261-263 ◽  
pp. 576-580
Author(s):  
Xiao Jing Yuan ◽  
Fan Liu

Flexible piers have been widely used in bridge engineering due to its superior ductility. The stirrup ratio and slenderness ratio were deemed to have a most important impact on hysteretic behavior of them. Five flexible piers were made under static vertical loads and low cyclic horizontal reversed loads. The process of test was introduced and failure mechanism, hysteretic behavior, skeleton curve, ductility, energy dissipation capacity, and stiffness degeneration of flexible piers were analyzed. Experimental studies show that (1) Failure mode of specimen is bending failure and their ductility factor falls between 4.15 and 6.30; (2) displacement ductility factor improves with increasing of the stirrup ratio. Stirrup could greatly improve the capacity on ductility and energy dissipation, while it has little impact on the bearing capacity; (3) ultimate bearing capacity decline with the increase of slenderness ratio, however, when the slenderness ratio member is larger, the hysteresis curve is fuller and energy-dissipation is better.


2011 ◽  
Vol 250-253 ◽  
pp. 2371-2375
Author(s):  
Hua Wei Zhao ◽  
Xiu Qin Cui ◽  
Tong Hao

Four constructional columns with concrete porous brick walls were constructed for low cyclic loading test. The damage on the characteristics and strength of the wall, hysteresis curve, ductility and other seismic performance were analyzed. Setting constructional columns in the wall at both ends increase the ultimate strength and improve its deformation, ductility and other properties. Meanwhile the height-wide-ratio of wall, axial pressure and other factors on the shear bearing capacity on the wall have been studied. Based on the shear capacity formula of wall in the Structural Seismic Design Code, considering the contribution of the constructional columns on the shear strength, according to the results, the shear capacity formula of constructional columns with concrete brick walls is presented.


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