• Title/Summary/Keyword: reinforced concrete structure

Search Result 1,500, Processing Time 0.03 seconds

Modelling of the effects of alkali-aggregate reaction in reinforced concrete structures

  • Pietruszczak, S.;Ushaksaraei, R.;Gocevski, V.
    • Computers and Concrete
    • /
    • v.12 no.5
    • /
    • pp.627-650
    • /
    • 2013
  • This paper deals with application of a non-linear continuum model for reinforced concrete affected by alkali-aggregate reaction (AAR) to analysis of some nuclear structures. The macroscopic behaviour of the material affected by AAR is described by incorporating a homogenization/averaging procedure. The formulation addresses the main stages of the deformation process, i.e., a homogeneous deformation mode as well as that involving localized deformation, associated with formation of macrocracks. The formulation is applied to examine the mechanical behaviour of some reinforced concrete structures in nuclear power facilities located in Quebec (Canada). First, a containment structure is analyzed subjected to 45 years of continuing AAR. Later, an inelastic analysis is carried out for the spent fuel pool taking into account the interaction with the adjacent jointed rock mass foundation. In the latter case, the structure is said to be subjected to continuing AAR that is followed by a seismic event.

Bolted end plate connections for steel reinforced concrete composite structures

  • Li, Xian;Wu, Yuntian;Mao, Weifeng;Xiao, Yan;Anderson, J.C.;Guo, Yurong
    • Structural Engineering and Mechanics
    • /
    • v.24 no.3
    • /
    • pp.291-306
    • /
    • 2006
  • In order to improve the constructability and meanwhile ensure excellent seismic behavior, several innovative composite connection details were conceived and studied by the authors. This paper reports experimental results and observations on seismic behavior of steel beam bolted to reinforced concrete column connections (bolted RCS or BRCS). The proposed composite connection details involve post tensioning the end plates of the steel beams to the reinforced concrete or precast concrete columns using high-strength steel rods. A rational design procedure was proposed to assure a ductile behavior of the composite structure. Strut-and-tie model analysis indicates that a bolted composite connection has a favorable stress transfer mechanism. The excellent capacity and behavior were then validated through five full-scale beam to column connection model tests.

A Study on the Reinforcement of Reinforced Concrete using Evolutionary Structural Optimization (점진적 구조 최적화 기법을 응용한 철근콘크리트 부재의 배근)

  • 윤성수;이정재
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.44 no.2
    • /
    • pp.127-135
    • /
    • 2002
  • Due to the fact that the design of a reinforced concrete structure changes in accordance with its shape and assigned load, total automation of the design system has not been achieved. For instance, since there is no general rule about setting up reinforcing steel quantity and arrangement location, it is simply not feasible to automatically decide the reinforcing arrangement location. In this study, the ESO(evolutionary structural optimization) technique and its related issues will be discussed. The ESO techniques is determined the reasonable load path which is traveling of load between in-flow and out-flow at a concrete structure using numerical analysis. And the results applied to the steel arrangement in reinforced concrete structures. The optimal algorithm, which determines the terminal criteria during ESO process, has been updated by using the obtained results. And the load path within the member has been determined automatically.

Analytical Study of Flexural Behavior on Steel Fiber Reinforced Concrete Structure (SFRC구조물의 휨거동에 관한 해석적 연구)

  • Seo, Seung-Tag
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.11 no.1
    • /
    • pp.35-40
    • /
    • 2008
  • Various characters of the concrete are greatly improved as the effect of the steel fiber. As the improvement effect of the steel fiber, the increment in flexural strength, shear strength, toughness, and impact strength are remarkable, and tenacious concrete is obtained. This paper presents model which can predict mechanical behavior of the structure according to aspect ratio and volume fraction of steel fiber. Experiments on compressive strength, elastic modulus and tensile strength were performed with self-made cylindrical specimens of variable aspect ratios. This paper presents an analytical study on the behavior of a beam specimen with steel fiber reinforced concrete(SFRC). The effect of the SFRC on the crack pattern, failure mode and the flexural behavior of the structure were investigated. The analysis model based on the nonlinear layered finite element method was successfully able to find the necessary amount of steel fibers, tensile steels and beam section which can best approximate flexural strength and ductility of a given conventionally reinforced concrete beam.

  • PDF

Probability-Based Prediction of Time to Corrosion Initiation of RC Structure Exposed to Salt Attack Environment Considering Uncertainties (불확실성을 고려한 RC구조물의 부식개시시기에 대한 확률 기반 예측)

  • Kim, Jin-Su;Do, Jeong-Yun;Hun, Seung;Soh, Seung-Young;Soh, Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.05b
    • /
    • pp.249-252
    • /
    • 2005
  • Chloride ingress is a common cause of deterioration of reinforced concrete structures. Modeling the chloride ingress is an important basis for designing reinforced concrete structures and for assessing the reliability of an existing structure. The modelling is also needed for predicting the deterioration of a reinforced structure. This paper presents an approach for the probabilistic modeling of the chloride-induced corrosion of reinforcement steel in concrete structures that takes into account the uncertainties in the physical models. The parameters of the models are modeled as random variables and the distribution of the corrosion time and probability of corrosion are determined by using Monte Carlo simulation. The predictions of the proposed model is very effective to do the decision-making about initiation time and deterioration degree.

  • PDF

Seismic behavior of SFRC shear wall with CFST columns

  • Gao, Dan-Ying;You, Pei-Bo;Zhang, Li-Juan;Yan, Huan-Huan
    • Steel and Composite Structures
    • /
    • v.28 no.5
    • /
    • pp.527-539
    • /
    • 2018
  • The use of reinforced concrete (RC) shear wall with concrete filled steel tube (CFST) columns and steel fiber reinforced concrete (SFRC) shear wall has aroused widespread attention in recent years. A new shear wall, named SFRC shear wall with CFST columns, is proposed in this paper, which makes use of CFST column and SFRC shear wall. Six SFRC shear wall with CFST columns specimens were tested under cyclic loading. The effects of test parameters including steel fiber volume fraction and concrete strength on the failure mode, strength, ductility, rigidity and dissipated energy of shear wall specimens were investigated. The results showed that all tested shear wall specimens exhibited a distinct shear failure mode. Steel fibers could effectively control the crack width and improve the distribution of cracks. The load carrying and energy dissipation capacities of specimens increased with the increase of steel fiber volume fraction and concrete strength, whilst the ductility of specimens increased with the increase of steel fiber volume fraction and the decrease of concrete strength.

Bond Stress of the Bar Removed Rust with Concrete (전식녹을 제거한 철근과 콘크리트의 부착응력에 관한 실험적 연구)

  • Choi, Hyo-Seok;Lee, Joo-Il;Ryu, Soo-Hyun;Yu, Ho-Hyun;Kim, Jin-Mu
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.5 no.1
    • /
    • pp.188-194
    • /
    • 2001
  • A reinforced concrete structure is complex structure that works as one body with bonding role of steel bar and concrete. The bonding action between steel bar and concrete makes possible the compound structure. The transmission of mutual strength of the steel bar with concrete in structure is determined by the bonding characteristic of steel bar and concrete surface. But the efficiency of bonding characteristic of steel bar is Questionable by the corrosion cause by the delay construction term, the wrong management, etc. So this study investigate bonding characteristic of reinforced concrete using pull-out test method which steel bar removed rust and the principal variables of this study are concrete compression strength and the degree of corrosion. The result showed that bonding strength tend to increase when removed rust of steel bar whereas it tend to decrease when not removed rust.

  • PDF

Study on the Quality Improvement through Analysis of the Cause of the Structure Design Drawing in the Internal Reinforced Concrete Structures

  • Kim, Byung-Yun
    • Journal of the Korea Institute of Building Construction
    • /
    • v.14 no.1
    • /
    • pp.76-86
    • /
    • 2014
  • The cause of crack on reinforced concrete structures is varied, while the studies, which have intended to analyze this in the material side, have been the mainstream so far. Therefore, in this study, we intended to suggest the proposals for enhancement of the system to reduce crack and to improve the quality of the reinforced concrete structures, by reviewing the cause of crack mainly in the structural aspect and analyzing the practices and the system. The result has been shown as following. (1) As one of the measures for improving the constructional system related to the structure, it is to enhance the relevant system so that design on construction, structure, and equipment, can be separately ordered or jointly ventured, and the owner or the agent of the owner can discuss and mediate the business in each specialized field. (2) Importance on construction supervision and new establishment of regulations related to structure supervision.

Seismic behavior of non-seismically designed reinforced concrete frame structure

  • Nguyen, Xuan-Huy;Nguyen, Huy Cuong
    • Earthquakes and Structures
    • /
    • v.11 no.2
    • /
    • pp.281-295
    • /
    • 2016
  • This paper presents a study on a non-seismically designed reinforced concrete (RC) frame structure. The structure was a existing three-story office building constructed according to the 1990s practice in Vietnam. The 1/3 scaled down versions of structure was tested on a shake table to investigate the seismic performance of this type of construction. It was found that the inter-story drift and the overall behavior of structure meet the requirements of the actual seismic design codes. Then, nonlinear time history analyses are carried out using the fiber beam- column elements. The comparison between the experimental and simulation results shows the performance of the time history analysis models.

Effectiveness of seismic isolation in a reinforced concrete structure with soft story

  • Hakan Ozturk;Esengul Cavdar;Gokhan Ozdemir
    • Structural Engineering and Mechanics
    • /
    • v.87 no.5
    • /
    • pp.405-418
    • /
    • 2023
  • This study focused on the effectiveness of seismic isolation technique in case of a reinforced concrete structure with soft story defined as the stiffness irregularity between adjacent stories. In this context, a seismically isolated 3-story reinforced concrete structure was analyzed by gradually increasing the first story height (3.0, 4.5, and 6.0 m). The seismic isolation system of the structure is assumed to be composed of lead rubber bearings (LRB). In the analyses, isolators were modeled by both deteriorating (temperature-dependent analyses) and non-deteriorating (bounding analyses) hysteretic representations. The deterioration in strength of isolator is due to temperature rise in the lead core during cyclic motion. The ground motion pairs used in bi-directional nonlinear dynamic analyses were selected and scaled according to codified procedures. In the analyses, different isolation periods (Tiso) and characteristic strength to weight ratios (Q/W) were considered in order to determine the sensitivity of structural response to the isolator properties. Response quantities under consideration are floor accelerations, and interstory drift ratios. Analyses results are compared for both hysteretic representations of LRBs. Results are also used to assess the significance of the ratio between the horizontal stiffnesses of soft story and isolation system. It is revealed that seismic isolation is a viable method to reduce structural damage in structures with soft story.