Behavior Study of High Impact Resistant Reinforced Concrete Frames Using Crack Conduction Method

2006 ◽  
Author(s):  
Navid Heidarzadeh ◽  
S. Mohammad Razavi ◽  
Nima Shamsaei
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Failure Modes ◽  
Side Surface ◽  
High Impact ◽  
Structural Behavior ◽  
Concrete Frames ◽  
Rc Frames ◽  
Behavior Study ◽  
Falling Weight

In this study, the influence of crack conduction method on behavior of reinforced concrete (RC) frame under iterative high impact loading were experimented. To investigate the structural behavior through large deformations and progressive damage and to identify the failure modes, the falling weight and falling height were set more than the structural strength in elastic state. A comprehensive scheme which indicated influence of location of initial cracks on behavior and failure mode of structure was developed. Falling weight impact test was conducted on twenty-one laboratory scaled RC frames which were categorized in four series regard to considered scheme. Concrete volume and compressive strength, number of longitudinal and transverse rebar were constant factors in all specimens. Deformed shape and crack patterns, developed on the side surface of the RC frames, were sketched and total deflections vs. cumulative input energy of the RC girder were plotted. The results revealed the influence of crack conduction on improving the structural behavior and extending the endurance of RC frames against iterative high impact loading.

scholarly journals Examination of Anchorage of Mesh Wire on Seismic Response of Infilled Walls in RC Frames

2021 ◽  
Author(s):  
Ali Al-Maliki ◽  
◽  
Mohammed Sahib Mohammed ◽  
Maha Al-Soudani ◽  
Haifaa Nasser Husein ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Lateral Load ◽  
Structural Behavior ◽  
Concrete Frames ◽  
Infill Wall ◽  
Infill Walls ◽  
Positive Effects ◽  
Rc Frames ◽  
Different Diameters

The infill walls may lose their positive effects during the first stages of earthquakes, either by leaving their plane or through breakage. That is why it is common to strengthen these walls before design earthquakes or to repair and strengthen them after suffering slight or moderate damage due to the occurrence of an earthquake. In this study, the effect of adding and strengthening these walls on the structural behavior of reinforced concrete structures was investigated. For this purpose, the infill walls were strengthened with a single mesh of reinforcement and covered with plaster. Five one-story, single bay and ½ scaled reinforced concrete frames were cast, one was built without infill, the second with a bare infill wall, and the other three with strengthened infill walls with anchorage of different diameters. All these specimens were tested under cyclic loading type reverse. The tests resulted in important relationships and curves, including the lateral load-lateral displacement, envelope curve-lateral load and lateral displacement, as well as stiffness- lateral displacement and others. Through these results, the effect of adding infill walls and the strengthening procedure of these walls on the structural behavior of the structures was discussed.

scholarly journals Rapid Retrofit of Reinforced Concrete Frames after Progressive Collapse to Increase Sustainability

2019 ◽  
Vol 11 (15) ◽  
pp. 4195 ◽  
Author(s):  
Li ◽  
Shan ◽  
Zhang ◽  
Li
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Design Method ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Frame Structure ◽  
Rc Frame ◽  
Concrete Frames ◽  
Before And After ◽  
Test Frame

A structural progressive collapse is usually a local failure, in which the damage is concentrated at beams that bridge the removal column and the column itself. In many cases, retrofitting the damaged structure is more economical and more sustainable than reconstructing the entire structure. A progressive collapse test of a 1/3 scale, four-bay by two-story reinforced concrete (RC) frame was conducted, after which the structure was retrofitted with carbon fiber reinforced polymer (CFRP) wraps and retested. The center column in the first story was removed and the frame was pushed down quasistatically under displacement control to investigate the progressive collapse performances of the retrofitted RC frame. The test results were represented systematically at different areas in terms of the resistance forces, crack developments, and local and global failure modes. Numerical models were built to verify the test frame before and after the retrofitting. A design method was proposed to retrofit an RC frame using CFRP wraps after a progressive collapse. The test frame was redesigned to improve the retrofitting and used as an example to demonstrate the rationality of the proposed retrofit design method. The results indicated that the proposed retrofitting technology rapidly restored the frame structure to its original capacity before the progressive collapse occurred, whilst consistently satisfying the priorities of being economical and sustainable.

Numerical Simulation of Impact Response Behavior of Rectangular Reinforced Concrete Slabs under Falling-Weight Impact Loading

2011 ◽  
Vol 82 ◽  
pp. 266-271 ◽  
Author(s):  
Norimitsu Kishi ◽  
Yusuke Kurihashi ◽  
Sara Ghadimi Khasraghy ◽  
Hiroshi Mikami
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Impact Loading ◽  
Dynamic Responses ◽  
Concrete Slabs ◽  
Analysis Method ◽  
Numerical Analysis Method ◽  
Reinforced Concrete Slabs ◽  
Weight Impact ◽  
Falling Weight

A numerical analysis method for rectangular reinforced concrete slabs under falling-weight impact loading is established. The proposed method using finite element analysis incor-porates a simple constitutive model for concrete elements. The applicability was investigatedcomparing the numerical results with the experimental data. Falling-weight impact tests wereconducted on reinforced concrete slabs with different supporting conditions. These were: a slabwith line supports on four sides; a slab with two line supports on two opposite sides (the othertwo sides were free); and a slab with one line and two corner-point supports. Following resultswere obtained from this study: (1) the time histories of dynamic responses are well predictedby using proposed numerical analysis method; (2) maximum reaction forces and the maximumdeflections in the slab center below the loading point, and characteristics of the damped freevibration after falling weight was rebounded, can be better predicted; and (3) major crackpatterns can be roughly predicted despite of support conditions.

scholarly journals Structural Behavior of Reinforced Self-Compacted Engineered Cementitious Composite Beams

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Bashar S. Mohammed ◽  
M. F. Nuruddin ◽  
Muhammad Aswin ◽  
Nursyuhada Mahamood ◽  
Hashem Al-Mattarneh
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Beam ◽  
Failure Modes ◽  
Reinforced Concrete Beam ◽  
Composite Beams ◽  
Experimental Results ◽  
Structural Behavior ◽  
Cementitious Composite ◽  
Engineered Cementitious Composite

Eight large-scale reinforced self-compacted engineered cementitious composite (R-SC-ECC) beams with different steel reinforcement ratios have been designed, prepared, cast, cured, and tested to failure at the age of 28 days. The experimental results have been compared with theoretical values predicted using EC2, RILEM, and VecTor2 models. Results show that failure modes in flexure and shear of R-SC-ECC beams are comparable to that of normal reinforced concrete beam. Nevertheless, contrary to VecTor2, models of EC2 and RILEM are not suitable for predicting reasonable ultimate moments for the beams, while results using VecTor2 model have successfully predicted the failure modes and load-deflection curves for all R-SC-ECC beams. It has been concluded that R-SC-ECC fall in the category of ductility class medium to high which gives advantages of using R-SC-ECC beams in regions susceptible to seismic activities.

Experimental study on bolted and anchored beam-to-column joints of prefabricated concrete frames

2019 ◽  
Vol 23 (2) ◽  
pp. 374-387
Author(s):  
Xizhi Zhang ◽  
Jiashu Hao ◽  
Dongchao Duan ◽  
Shengbo Xu ◽  
Shaohua Zhang ◽  
...  
Keyword(s):  
Failure Modes ◽  
Plastic Hinge ◽  
Side Surface ◽  
Concrete Frames ◽  
Initial Stiffness ◽  
End Plate ◽  
New Type ◽  
Column Joint ◽  
The Difference ◽  
Cyclic Loading Tests

A new type of beam-to-column joint used in prefabricated concrete frames was proposed in this study. In this joint, the longitudinal bars at the top of the beam are anchored to the column using straight thread sleeves, and the bars at the bottom are welded to the steel fastener that is bolted to the column. Cyclic loading tests of three specimens, namely, two beam–column joints of this type and a cast-in-place beam–column joint, were conducted to study the seismic behavior and feasibility of this type of joint. The difference between the two prefabricated joints is the shape of the holes on the end plate. Failure modes of the specimens were observed and analyzed. The hysteretic curves, bearing capacities, stiffness degeneration, ductility, and energy-dissipating capacities of the specimens were compared and studied. Test results indicated that all beam–column joints exhibited beam hinge failure. No slippage was observed between the concrete and horizontal plates of the steel fasteners used in the new type of joint. The bearing capacity and initial stiffness of both prefabricated specimens compared with the cast-in-place ones were increased. The steel fastener could increase the distance between the plastic hinge and the side surface of the column while enlarging the length of the plastic hinge. The trend of energy dissipation and stiffness degeneration of the specimens were similar, and the ductility coefficient ranged from 2.7 to 4.91. The displacement angles of the joints exceeded 1/50 before the failure of the specimens. The mechanical behavior of both prefabricated joints was similar, but the joint with U-shaped holes on the end plate was convenient to create.

Ductility Reduction Factors for Masonry-Infilled Reinforced Concrete Frames

2015 ◽  
Vol 31 (1) ◽  
pp. 339-365 ◽  
Author(s):  
Manish Kumar ◽  
Durgesh C. Rai ◽  
Sudhir K. Jain
Keyword(s):  
Reinforced Concrete ◽  
Traditional Approach ◽  
Statistical Tests ◽  
Experimental Studies ◽  
Reduction Factor ◽  
Model Parameters ◽  
Deformation Model ◽  
Concrete Frames ◽  
Ductility Demand ◽  
Rc Frames

Masonry-infilled reinforced concrete (RC) frames are popular structural systems; however, there is much uncertainty in their response under seismic loads. Using the data from past experimental studies, a simple force-deformation model with three control points was developed. The effect of the model parameters on the ductility reduction factor (DRF) and ductility demand (DD) was examined. Statistical tests indicated that the ratio of residual strength to peak strength was the most significant parameter. The traditional approach to determining DRF ordinates through iteration for an assumed value of ductility may result in inappropriate DRF values because of the nonmonotonic relationship between DRF and DD. Constant ductility charts were developed to appropriately account for nonmonotonicity. It was found that the allowable DRF may be much higher if relatively weaker infill compared to the strength of the frame is used, which underscores the need for modifying code provisions because they allow relatively strong infill.

scholarly journals Effect of Different Bracing Systems in Reinforced Concrete Frames under Cyclic Loading

2020 ◽  
Vol 9 (7) ◽  
pp. 704-708
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Structural Parameters ◽  
Rc Frame ◽  
Concrete Frames ◽  
Element Analysis ◽  
Framed Structures ◽  
Rc Frames ◽  
Seismic Force ◽  
Rc Framed Structures

Reinforced concrete (RC) framed structures are widely used as load transferring system in residential and commercial buildings. Even though the RC frames are designed for gravitational and seismic forces, but they are week under severe seismic events. The main disadvantage of the framed structures is inefficient bracing systems designed in it. This investigation is conducted mainly to study the effective bracing system in the RC framed structure to transfer the seismic force. This research aims to study the seismic performance of RC frames influenced by the various types of cross bracings under cyclic loading. The finite element analysis software package ABAQUS is used to investigate the braced RC frames analytically. The research scheme consists of three RC frames; the bare frame, the bare frame with single X-bracing (X frame), double X bracing (D-X frame) along the height. The structural parameters include, load-displacement hysteresis envelope, stiffness degradation and energy absorption were studied to analyze the performance of bracings. The results showed that the X frame and D-X frame noticeably increased the lateral strength, stiffness and energy dissipation properties compared to the bare RC frame. The results also indicated that the addition of X bracing along the height significantly enhanced the structural parameters of the RC frame.

scholarly journals Strength and ductility in reinforced concrete frames designed with Mexican codes

1990 ◽  
Vol 23 (3) ◽  
pp. 184-197 ◽  
Author(s):  
M. Rodriguez
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Analytical Models ◽  
Reinforcing Steel ◽  
Concrete Frames ◽  
Approximate Methods ◽  
Reinforced Concrete Frames ◽  
Rc Frames ◽  
Mexico Earthquake ◽  
Strength And Ductility

The strength and ductility capacities of several structural sections of members in typical reinforced concrete frames designed with Mexican Codes are calculated using analytical models for confined concrete and reinforcing steel. These ductility capacities are associated with global displacement ductilities in the RC frames using approximate methods of analysis described in this paper. Results obtained in this investigation are correlated with typical pattern of structural damage in RC frames observed during the 1985 Mexico Earthquake. Some aspects of the seismic performance of fully ductile frames designed according to the 1987 Mexico City Building Code are also discussed, as well as the effect of some mechanical properties of reinforcing steel on the strength and ductility of RC frames.

scholarly journals Impact of Earthquake Types and Aftershocks on Loss Assessment of Non-Code-Conforming Buildings: Case Study with Victoria, British Columbia

2017 ◽  
Vol 33 (2) ◽  
pp. 551-579 ◽  
Author(s):  
Solomon Tesfamariam ◽  
Katsuichiro Goda
Keyword(s):  
British Columbia ◽  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Concrete Frames ◽  
Loss Assessment ◽  
Rc Frames ◽  
Annual Probability ◽  
Story Drift ◽  
Hysteretic Characteristics ◽  
The Impact

This paper presents a study on the impact of earthquake types (shallow crustal, deep inslab, and megathrust Cascadia interface earthquakes) and aftershocks on loss assessment of non-code-conforming reinforced concrete (RC) buildings. The loss assessment is formulated within the performance-based earthquake engineering framework. The dependency between the maximum and residual inter-story drift ratios are captured using copulas. Finite-element models that take into account key hysteretic characteristics of non-ductile RC frames were adopted and incremental dynamic analysis is utilized to compute collapse risk. The proposed procedure is applied to a set of 2-, 4-, 8-, and 12-story non-ductile reinforced concrete frames located in Victoria, British Columbia, Canada. From the results, the aftershock showed marked difference for the 2-story building. At annual probability of 10−2–10−3, crustal and inslab events with Mw6.5 to Mw7.5 contributed the most to the loss as these events occur more frequently. At rarer annual probability of 10−3–10−4, the Cascadia event having Mw8.5 to Mw9.0 is predominant and contributed the most to the loss.

Sign in / Sign up

Export Citation Format

Share Document