Experimental Study on the Effect of Moisture Content on Hysteretic Behavior of Reinforced Concrete Columns

2018 ◽  
Vol 12 (1) ◽  
pp. 47-61
Author(s):  
Wenjuan Lv ◽  
Baodong Liu ◽  
Ming Li ◽  
Lin Li ◽  
Pengyuan Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Moisture Content ◽  
Early Stage ◽  
Damping Ratio ◽  
Concrete Columns ◽  
Hysteretic Behavior ◽  
Cyclic Test ◽  
Experimental Result ◽  
Reinforced Concrete Columns

Background: For reinforced concrete structures under different humid conditions, the mechanical properties of concrete are significantly affected by the moisture content, which may result in a great change of the functional performance and bearing capacity. Objective: This paper presents an experiment to investigate the influence of the moisture content on the dynamic characteristics and hysteretic behavior of reinforced concrete column. Results: The results show that the natural frequency of reinforced concrete columns increases quickly at an early stage of immersion, but there is little change when the columns are close to saturation; the difference between the natural frequencies before and after cyclic test grows as the moisture content rises. The damping ratio slightly decreases first and then increases with the increase of moisture content; the damping ratio after the cyclic test is larger than before the test due to the development of the micro-cracks. Conclusion: The trend of energy dissipation is on the rise with increasing moisture content, although at an early stage, it decreases slightly. According to the experimental result, a formula for the moisture content on the average energy dissipation of reinforced concrete columns is proposed.

A combined experimental and numerical analysis on the seismic behavior of short reinforced concrete columns with different structural sizes and axial compression ratios

2017 ◽  
Vol 27 (9) ◽  
pp. 1416-1447 ◽  
Author(s):  
Liu Jin ◽  
Shuai Zhang ◽  
Dong Li ◽  
Haibin Xu ◽  
Xiuli Du ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Axial Compression ◽  
Seismic Behavior ◽  
Load Capacity ◽  
Concrete Columns ◽  
Simulation Method ◽  
Reinforced Concrete Columns ◽  
Mesoscopic Simulation ◽  
Energy Dissipation Capacity

The results of an experimental program on eight short reinforced concrete columns having different structural sizes and axial compression ratios subjected to monotonic/cyclic lateral loading were reported. A 3D mesoscopic simulation method for the analysis of mechanical properties of reinforced concrete members was established, and then it was utilized as an important supplement and extension of the traditional experimental method. Lots of numerical trials, based on the restricted experimental results and the proposed 3D mesoscopic simulation method, were carried out to sufficiently evaluate the seismic performances of short reinforced concrete columns with different structural sizes and axial compression ratios. The test results indicate that (1) the failure pattern of reinforced concrete columns can be significantly affected by the shear-span ratio; (2) increasing the axial compression ratio could improve the load capacity of the reinforced concrete column, but the deformation capacity would be restricted and the failure mode would be more brittle, consequently the energy dissipation capacity could be deteriorated; and (3) the load capacity, the displacement ductility, and the energy dissipation capacity of the short reinforced concrete columns all exhibit clear size effect, namely, the size effect could significantly affect the seismic behavior of reinforced concrete columns.

Strength Degradation and Energy Dissipation of Stainless Steel Reinforced Concrete Columns

2011 ◽  
Vol 90-93 ◽  
pp. 1614-1617
Author(s):  
Guo Xue Zhang ◽  
Chang Wei Wang ◽  
Zhi Hao Zhang
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Ductile Failure ◽  
Concrete Columns ◽  
Strength Degradation ◽  
Reinforced Concrete Columns ◽  
Failure Characteristics ◽  
Steel Reinforced Concrete ◽  
Steel Rebar

Three specimens with ribbed stainless steel rebar and one specimen with ribbed ordinary steel rebar are tested concerning the strength degradation and energy dissipation of stainless steel reinforced concrete columns. The tests results indicate that the damage of the specimens exhibit ductile failure characteristics, and the reinforced concrete columns with stainless steel rebar damage to a lesser extent, appear good ductility and energy dissipation. The strength degradation of stainless steel reinforced column with high axial compression ratio is quite obvious, and with the increasing of the stirrup ratio of column with stainless steel rebar, the strength of column is enhanced.

scholarly journals Equivalent Viscous Damping Ratio Model for Flexure Critical Reinforced Concrete Columns

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Qin Zhang ◽  
Zong-yan Wei ◽  
Jin-xin Gong ◽  
Ping Yu ◽  
Yan-qing Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Damping Ratio ◽  
Hysteretic Behavior ◽  
Viscous Damping ◽  
Ratio Model ◽  
Rc Columns ◽  
Equivalent Viscous Damping ◽  
Rc Structures ◽  
Energy Dissipation Capacity

In order to determine the energy dissipation capacity of flexure critical reinforced concrete (RC) columns reasonably, an expression for describing the hysteretic behavior including loading and unloading characteristics of flexure critical RC columns is presented, and then, a new equivalent viscous damping (EVD) ratio model including its simplified format, which is interpreted as a function of a displacement ductility factor and a ratio of secant stiffness to yield stiffness of columns, is developed based on the proposed hysteretic loop expression and experimental data from the PEER column database. To illustrate the application of the proposed equivalent damping ratio model, a case study of pushover analysis on a flexure critical RC bridge with a single-column pier is provided. The analytical results are also compared with the results obtained by other models, which indicate that the proposed model is more general and rational in predicting energy dissipation capacity of flexure critical RC structures subjected to earthquake excitations.

Effect of Axial Compression Ratio on Seismic Behavior of GFRP Reinforced Concrete Columns

2020 ◽  
Vol 20 (06) ◽  
pp. 2040004
Author(s):  
Li Sun ◽  
Zeyu Yang ◽  
Qiao Jin ◽  
Weidong Yan
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Axial Compression ◽  
Seismic Design ◽  
Compression Ratio ◽  
Seismic Behavior ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
Axial Compression Ratio ◽  
Energy Dissipation Capacity

Traditional reinforced concrete columns have demonstrated poor seismic performance especially in corrosive environment as the reinforcement bars experience severe corrosion under such conditions. To overcome the problem of steel corrosion, glass fiber-reinforced polymer (GFRP) reinforced concrete columns have gained significant attention in recent years. However, the seismic performance of GFRP reinforced concrete column is not well understood yet. One of the main challenges associated with the use of GFRP bars is its brittle behavior. Therefore, it is necessary to investigate the mechanical properties and failure modes of GFRP reinforced concrete structures under seismic action. In this research, the seismic behavior of GFRP reinforced concrete columns and conventional columns under different axial compression ratios are analyzed by low-cycle repeated pseudo-static loading tests. As a result, the deformation and the seismic energy dissipation capacity of GFRP reinforced concrete columns are investigated and discussed. Furthermore, the failure mechanism of GFRP bar structure is studied to provide the basis for improving the seismic design method of GFRP reinforced concrete structure and modifying the code for seismic design. In addition, the influence of axial compression ratio on the seismic behavior of full GFRP reinforced concrete columns is investigated. The results of this experiment demonstrate that with the increase of axial compression ratio, the ultimate bearing capacity of GFRP reinforced concrete columns increases, while the deformation and the cumulative energy dissipation capacity decrease.

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

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