The effects of CFRP orientation on the strengthening of reinforced concrete structures

2019

Structural Concrete

This paper presents experimental and numerical investigations on the behavior of axially‐loaded concrete walls restrained on three sides (TW3S walls). Particular emphasis was given to the influences of varying the slenderness ratio, aspect ratio, concrete strength, and eccentricity on the ultimate axial strength of TW3S walls. Because of the overly conservative nature of the code design equations and the scarcity of other available models for estimating the ultimate axial strength of TW3S walls, a more encompassing design equation has been developed. Comparisons with the test data of the current and previous studies confirmed that the proposed equation is satisfactory and reliable.

Section: Finite Element Modelmentioning

confidence: 99%

Section: Ultimate Strengthmentioning

confidence: 99%

Prediction of ultimate strength of concrete walls restrained on three sides

2019

Structural Concrete

“…The tensile fracture and compressive plastic behaviour are completed by specifying the evolution laws of damage, which represents the stiffness degradation. The compression damage, d c , and the tension damage, d t , were calculated by the equations below after the peak stress:

d_{c} = 1 - \frac{σ_{c}}{f_{c}^{'}},

d_{t} = 1 - \frac{σ_{t}}{f_{italicct}^{'}} .

…”

Section: Numerical Modelling Using Abaqusmentioning

confidence: 99%

Experimental and numerical investigations of axially loaded RC walls restrained on three sides

Structural Design Tall Build

2018

Self Cite

Axially loaded reinforced concrete (RC) walls in tilt-up structures can be supported top and bottom only by floors or roof structures. However, RC walls are often combined to form I-, C-, T-, and L-shapes to make efficient use of the building area in multi-storey buildings. With these configurations, walls may also be laterally supported on either or both sides by interconnecting walls. While many researchers have investigated the behaviours of RC walls, either in one-way action or two-way action supported on four sides with and without openings, limited research has been conducted on two-way action walls supported on three sides (TW3S). As such, this paper experimentally and numerically investigates the behaviour of TW3S walls. Details of the 12 half-scale walls tested, including experimental setup, failure loads, crack patterns, and load-deflection characteristics, are reported. In addition, the Finite Element Method using ABAQUS software for investigating the behaviour of TW3S walls is described in detail. Finally, due to the conservative nature of code design equations and there being limited available methods for predicting the ultimate load of TW3S walls with openings, a rigid-plastic approach has been proposed in this study to evaluate the failure load of TW3S walls. KEYWORDS aspect ratio, axial load, concrete walls, openings, slenderness ratio, yield line | INTRODUCTIONReinforced concrete (RC) walls have been commonly used as load-bearing elements in buildings and offshore structures. Primary applications include tilt-up precast structures, shear walls in multi-storeyed buildings, lift core walls in high-rise buildings, components in bridge construction such as webs of beams or box girders, storage cells in offshore concrete structures, and parts of floating concrete structures such as barges and pontoons. [1] In general, typical loadings on RC walls are in-plane loads, consisting of gravitational and shear forces, and out-of-plane transverse loads. In-plane vertical loads are frequently eccentric, causing a pronounced out-of-plane curvature owing to a range of loading conditions including corbel elements applied to the wall face, imperfections in construction, uneven loading being experienced on top of the wall, and temporary loading during operation and/or maintenance. [2] Walls can be constructed with various support conditions. Walls restrained top and bottom only by floor plates, with free vertical edges, are usually encountered in tilt-up concrete structures. Such walls behave in one-way (OW) action depicted by uniaxial curvature in the direction of loading, as shown in Figure 1(a). In practice, walls behaving in two-way action supported on three sides (TW3S) and supported on four sides (TW4S), provided by floor plates and stiffening walls, or other sufficiently stiff members, are usually encountered in monolithic concrete structures, particularly in core walls of tall buildings. These panels generally deform along both the horizontal and vertical directions, as outlined in Figure 1(b-c). As a resul...

“…in which ρ is the concrete density and may be taken as 2400 kg/m 3 . These empirical equations were also used to simulate the concrete walls' properties by Lima et al (2016).…”

Section: Concrete In Compressionmentioning

confidence: 99%

Instability analysis of reinforced concrete walls with various support conditions

Structural Design Tall Build

Fragomeni

2017

Self Cite

SummaryAxially loaded reinforced concrete walls can be designed using simplified design methods given in codes such as the Australian Concrete Standard Code (AS3600‐09) and the American Concrete Institute Code (ACI318‐14). However, these practical equations are based on empirical models, and their scope of application is still limited. In particular, walls with the various support conditions, high slenderness, and aspect ratios have been given little treatment. Recent research has been undertaken on the applicability of more reliable and accurate wall design methods. This paper initially presents a derived numerical technique incorporated in a computer program (WASTABT), to implement the iterative analysis for concrete walls with various support conditions. The outputs from the WASTABT program are verified using the results obtained from previous experimental results. A parametric study is then conducted using the verified computer‐based numerical technique to analyse axially loaded reinforced concrete panels. The study focuses on the effect of varying panel properties such as slenderness ratios, aspect ratios, concrete strengths, eccentricities, and reinforcement ratios, along with varying support conditions.