Time-Varying Law Experimental Research of the Interaction of Concrete Structure and Formwork Support during the Construction Period

2014 ◽  
Vol 488-489 ◽  
pp. 466-469
Author(s):  
Qing Rong Tang ◽  
Zhi Qiang Fu
Keyword(s):  
Support System ◽  
Concrete Structure ◽  
Environmental Temperature ◽  
Mechanical Performance ◽  
Live Load ◽  
Curing Time ◽  
Reinforced Concrete Frame ◽  
Construction Period ◽  
Concrete Frame ◽  
Test Models

Research for mechanism of concrete structure interacting with formwork support by manufacturing 2 test models of two-layer and single-span reinforced concrete frame at laboratory,and analysis interaction performance between concrete structure and formwork support and the influence of construction period,curing time of concrete and load on mechanical performance of formwork support system during the construction period.Research data shows:formwork support system interacted with concrete structure is a linear system when live load applied is smaller then crack load calculated according to mechanical indicators of loading-age concrete;load applied by formwork support system decreases with develop of curing time of concrete and removal of bottom support and construction period extension;it is also effected by environmental temperature.

Study on Mechanical Performance of Wall-Column Subassembly in New Precast Reinforced Concrete Frame-Shearwall Structure

2013 ◽  
Vol 351-352 ◽  
pp. 1014-1017
Author(s):  
Hao Zhang ◽  
Jia Xin Tong ◽  
Wei Jian Zhao ◽  
Chang Zheng Sun
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Kinematic Hardening ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Finite Element Software ◽  
Connection Method ◽  
Engineering Designs

A practical connection method of wall-column subassembly in new precast reinforced concrete frame-shearwall structure was proposed in this paper. Based on the general finite element software ABAQUS, numerical simulations were carried out on the mechanical performance of the precast and cast-in-situ wall-column subassemblies by using concrete damaged plastic model and bilinear kinematic hardening model. Results showed that mechanical performance of the precast wall-column subassembly, such as carrying capacities, deformations and failure modes, were almost equal to the cast-in-situ wall-column subassembly. Feasibility of the connection method which this paper proposed is verified preliminarily. The research results can provide theoretical references for related experimental researches, engineering designs and constructions.

The Application Research on the Carbon Fiber Sheet Reinforcement Technique in the Frame Beamstrengthening

2012 ◽  
Vol 594-597 ◽  
pp. 1018-1024
Author(s):  
Ling Xu ◽  
Wei Ze Gao
Keyword(s):  
Carbon Fiber ◽  
Concrete Structure ◽  
Application Research ◽  
Capacity Design ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Fiber Sheet ◽  
Design Requirements ◽  
Reinforcement Design ◽  
Carbon Fiber Sheet

In this paper,the author is according to aengineering example,to the problem of Reinforced Concrete Frame Structureis shortage of bearing capacity of beamson the Increment of Storey,according tothe requirement of the specifications of the concrete structure reinforcement design,through comparing the different reinforcing method of reinforcement design,take Carbon fiber sheetreinforcement and strengtheningmeasures,Make frame beams achieve the capacity design requirements,realize reasonable Increment of Storey, Further discusses the application of carbon fiber sheet in reinforcement.

scholarly journals Numerical Investigation of Innovative Support Frame of Openings in the Segmental Tunnel Lining

2020 ◽  
Vol 14 (1) ◽  
pp. 358-369
Author(s):  
Sanaz Ebrahimi ◽  
Mir Raouf Hadei ◽  
Alireza Rashiddel ◽  
Mohsen Hajihassani
Keyword(s):  
Support System ◽  
Steel Structures ◽  
Steel Frame ◽  
Concrete Lining ◽  
Reinforced Concrete Frame ◽  
Maximum Displacement ◽  
Segmental Lining ◽  
Concrete Frame ◽  
Temporary Support ◽  
Stress And Deformation

Introduction: To supply safety in the tunnels, it is necessary to construct escape routes and emergency exits that are performed by locating cross passages. Methods: These passages connect two tunnels transversely and apply escape routes. Using temporary steel structures to supply the ring stability in practice and reinforced concrete frame to stabilize the ring permanently can be appropriate to form a solid frame that transfers the opened ring's load to the opening surroundings. In this paper, a 3D finite element simulation was performed to analyze the influence of opening construction in the segmental concrete lining and a temporary support system. Using the simulation, stress and deformation distribution of the steel frame, bolts, and segmental lining were obtained. Results: The results show that by increasing the number of bolts from 18 to 30, the induced stress in the steel frame and bolts decreased to 76 and 59 percent, respectively. In addition, the maximum displacement in the segmental lining and the maximum opening value of the joints decline to 62.7 and 75 percent, respectively. Conclusion: Finally, it can be concluded that the steel frame can be used as a temporary support system.

The Seismic Performance Analysis of the Abnormal Joints Core Area of the Reinforced Concrete Frame Variable Beam Shaped

2014 ◽  
Vol 1008-1009 ◽  
pp. 1326-1329
Author(s):  
Shu Dian Yao ◽  
Fu Ma
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Mechanical Performance ◽  
Reinforced Concrete Beam ◽  
Core Area ◽  
Reinforced Concrete Frame ◽  
Element Analysis ◽  
Concrete Frame

The finite element analysis software-ANYSIS is used to calculate and analyze the deformation and mechanical performance of the abnormal joints core zone of variable beam shaped (reinforced concrete beam) under the positive and negative symmetric loads (simulate earthquake loads) . With the method of control variables, multiple finite element analysis models are set up and the focus is to explore the crack development, stress distribution and failure pattern in different stages. The compared conclusion shows that the shear failure of small joint core is the key to the whole joints core area for variable beam shaped.

scholarly journals Shear Behavior of a Reinforced Concrete Frame Retrofitted with a Hinged Steel Damping System

2020 ◽  
Vol 12 (24) ◽  
pp. 10360
Author(s):  
Hyun-Do Yun ◽  
Sun-Woong Kim ◽  
Wan-Shin Park ◽  
Sun-Woo Kim
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Seismic Retrofitting ◽  
Reinforced Concrete Frame ◽  
Main Research ◽  
Torsion Spring ◽  
Concrete Frame ◽  
Energy Dissipation Capacity ◽  
Research Questions ◽  
Torsion Springs

The purpose of this study was to experimentally evaluate the effect of a hinged steel damping system on the shear behavior of a nonductile reinforced concrete frame with an opening. For the experimental test, a total of three full-scale reinforced concrete frame specimens were planned, based on the “no retrofitting” (NR) specimens with non-seismic details. The main research questions were whether the hinged steel damping system is reinforced and whether torsion springs are installed in the hinged steel damping system. From the results of the experiment, the hinged steel damping system (DR specimen) was found to be effective in seismic retrofitting, while isolating the opening of the reinforced concrete (RC) frame, and the torsion spring installed at the hinged connection (DSR specimen) was evaluated to be effective in controlling the amount of deformation of the upper and lower dampers. The strength, stiffness, and energy dissipation capacity of the DSR specimen were slightly improved compared to the DR specimen, and it was confirmed that stress redistribution was induced by the rotational stiffness of the torsion spring installed in the hinge connection between the upper and lower frames.

scholarly journals Challenges in Evaluating Seismic Collapse Risk for RC Buildings

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jin Zhou ◽  
Zhelun Zhang ◽  
Tessa Williams ◽  
Sashi K. Kunnath
Keyword(s):  
Ground Motion ◽  
Seismic Vulnerability ◽  
Ground Motions ◽  
Primary System ◽  
Fragility Functions ◽  
Reinforced Concrete Frame ◽  
Ground Motion Selection ◽  
Concrete Frame ◽  
Frame Building ◽  
Seismic Collapse

AbstractThe development of fragility functions that express the probability of collapse of a building as a function of some ground motion intensity measure is an effective tool to assess seismic vulnerability of structures. However, a number of factors ranging from ground motion selection to modeling decisions can influence the quantification of collapse probability. A methodical investigation was carried out to examine the effects of component modeling and ground motion selection in establishing demand and collapse risk of a typical reinforced concrete frame building. The primary system considered in this study is a modern 6-story RC moment frame building that was designed to current code provisions in a seismically active region. Both concentrated and distributed plasticity beam–column elements were used to model the building frame and several options were considered in constitutive modeling for both options. Incremental dynamic analyses (IDA) were carried out using two suites of ground motions—the first set comprised site-dependent ground motions, while the second set was a compilation of hazard-consistent motions using the conditional scenario spectra approach. Findings from the study highlight the influence of modeling decisions and ground motion selection in the development of seismic collapse fragility functions and the characterization of risk for various demand levels.

scholarly journals Rational Choice of Reinforcement of Reinforced Concrete Frame Corners Subjected to Opening Bending Moment

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3438
Author(s):  
Michał Szczecina ◽  
Andrzej Winnicki
Keyword(s):  
Cross Section ◽  
Bending Moment ◽  
Plasticity Model ◽  
Reinforced Concrete Frame ◽  
Moment Frame ◽  
Concrete Frame ◽  
Rational Reinforcement ◽  
Eurocode 2 ◽  
Analysis Of Results

This paper discusses a choice of the most rational reinforcement details for frame corners subjected to opening bending moment. Frame corners formed from elements of both the same and different cross section heights are considered. The case of corners formed of elements of different cross section is not considered in Eurocode 2 and is very rarely described in handbooks. Several reinforcement details with both the same and different cross section heights are presented. The authors introduce a new reinforcement detail for the different cross section heights. The considered details are comprised of the primary reinforcement in the form of straight bars and loops and the additional reinforcement in the form of diagonal bars or stirrups or a combination of both diagonal stirrups and bars. Two methods of static analysis, strut-and-tie method (S&T) and finite element method (FEM), are used in the research. FEM calculations are performed with Abaqus software using the Concrete Damaged Plasticity model (CDP) for concrete and the classical metal plasticity model for reinforcing steel. The crucial CDP parameters, relaxation time and dilatation angle, were calibrated in numerical tests in Abaqus. The analysis of results from the S&T and FE methods allowed for the determination of the most rational reinforcement details.

Deformation Characteristics of Reinforced Concrete Beam-Column Joint Cores under Earthquake Loading

2003 ◽  
Vol 6 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sayed A. Attaalla ◽  
Mehran Agbabian
Keyword(s):  
Reinforced Concrete ◽  
Shear Deformation ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Frame ◽  
Bond Failure ◽  
Strain Compatibility ◽  
Concrete Frame ◽  
Column Joint ◽  
Reinforced Concrete Frame Structures

The characteristics of the shear deformation inside the beam-column joint core of reinforced concrete frame structures subjected to seismic loading are discussed in this paper. The paper presents the formulation of an analytical model based on experimental observations. The model is intended to predict the expansions of beam-column joint core in the horizontal and vertical directions. The model describes the strain compatibility inside the joint in an average sense. Its predictions are verified utilizing experimental measurements obtained from tests conducted on beam-column connections. The model is found to adequately predict the components of shear deformation in the joint core and satisfactorily estimates the average strains in the joint hoops up to bond failure. The model may be considered as a simple, yet, important step towards analytical understanding of the sophisticated shear mechanism inside the joint and may be implemented in a controlled-deformation design technique of the joint.

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