scholarly journals Shrinkage and temperature reinforcement in concrete liquid-containing structures.

2021 ◽  
Author(s):  
Nima Ziaolhagh
Keyword(s):  
Nonlinear Finite Element ◽  
Structural Elements ◽  
Concrete Member ◽  
Minimum Area ◽  
Element Analysis ◽  
Concrete Walls ◽  
Tensile Stresses ◽  
Concrete Members ◽  
Reinforced Concrete Walls ◽  
Codes Of Practice

Cracking due to shrinkage is a widespread problem in large concrete members such as walls and slabs. When shrinkage strains are restrained, tensile stresses develop in concrete. Concrete cracks when tensile stresses exceed the tensile strength of concrete. In general, concrete standards and codes of practice recommend a minimum area of reinforcement for shrinkage and temperature effects. In some cases, large structural elements provide significant restraint to a concrete member that the specified minimum area of reinforcement needs to be increased. This research studies the response of reinforced concrete walls to shrinkage strains. In this study, nonlinear finite element analysis is applied to simulate the cracking behaviour of concrete and predict crack pattern and tensile stresses in reinforcement in the vicinity of cracks. This research is looking for the effective shrinkage and temperature reinforcement in liquid-containing structures where cracking of concrete is of major concern.

scholarly journals Shrinkage and temperature reinforcement in concrete liquid-containing structures.

2021 ◽  
Author(s):  
Nima Ziaolhagh
Keyword(s):  
Nonlinear Finite Element ◽  
Structural Elements ◽  
Concrete Member ◽  
Minimum Area ◽  
Element Analysis ◽  
Concrete Walls ◽  
Tensile Stresses ◽  
Concrete Members ◽  
Reinforced Concrete Walls ◽  
Codes Of Practice

Cracking due to shrinkage is a widespread problem in large concrete members such as walls and slabs. When shrinkage strains are restrained, tensile stresses develop in concrete. Concrete cracks when tensile stresses exceed the tensile strength of concrete. In general, concrete standards and codes of practice recommend a minimum area of reinforcement for shrinkage and temperature effects. In some cases, large structural elements provide significant restraint to a concrete member that the specified minimum area of reinforcement needs to be increased. This research studies the response of reinforced concrete walls to shrinkage strains. In this study, nonlinear finite element analysis is applied to simulate the cracking behaviour of concrete and predict crack pattern and tensile stresses in reinforcement in the vicinity of cracks. This research is looking for the effective shrinkage and temperature reinforcement in liquid-containing structures where cracking of concrete is of major concern.

scholarly journals Thick Reinforced Concrete Walls Subjected To Non-Uniform Restrained Shrinkage

2021 ◽  
Author(s):  
Ali Jourabloo
Keyword(s):  
Reinforced Concrete ◽  
Reinforcement Ratio ◽  
Restrained Shrinkage ◽  
Concrete Walls ◽  
Cracking Behavior ◽  
Tensile Stresses ◽  
Minimum Reinforcement ◽  
Reinforced Concrete Walls ◽  
Codes Of Practice ◽  
Degree Of Restraint

Several researchers have studied the behavior of reinforced concrete walls under restraint shrinkage, which demonstrate the variation of the degree of restraint with different Length/Height ratios. In general, concrete standards and codes of practice recommend a minimum amount of reinforcement for shrinkage effects. This research investigates the response of thick reinforced concrete walls subjected to restraint shrinkage. The parameters studied are the thickness of reinforced concrete walls, and non-uniform distribution of shrinkage along the Length\Height and through the thickness of the wall. This study uses the non-linear finite element method to simulate the cracking behavior of the concrete and to predict tensile stresses in the reinforcement in the vicinity of Cracks. Moreover, this study investigates the influence of reinforcement ratio and compares the results with well-known concrete standards and codes of practice. It is concluded that the non-uniform shrinkage through the thickness of the wall may have significant impact on the cracking behavior of thick concrete walls. In addition, as expected, higher reinforcement ratio results in lower tensile stresses in the reinforcement. The thesis also provides guidelines for minimum reinforcement ratio.

scholarly journals Thick Reinforced Concrete Walls Subjected To Non-Uniform Restrained Shrinkage

2021 ◽  
Author(s):  
Ali Jourabloo
Keyword(s):  
Reinforced Concrete ◽  
Reinforcement Ratio ◽  
Restrained Shrinkage ◽  
Concrete Walls ◽  
Cracking Behavior ◽  
Tensile Stresses ◽  
Minimum Reinforcement ◽  
Reinforced Concrete Walls ◽  
Codes Of Practice ◽  
Degree Of Restraint

Several researchers have studied the behavior of reinforced concrete walls under restraint shrinkage, which demonstrate the variation of the degree of restraint with different Length/Height ratios. In general, concrete standards and codes of practice recommend a minimum amount of reinforcement for shrinkage effects. This research investigates the response of thick reinforced concrete walls subjected to restraint shrinkage. The parameters studied are the thickness of reinforced concrete walls, and non-uniform distribution of shrinkage along the Length\Height and through the thickness of the wall. This study uses the non-linear finite element method to simulate the cracking behavior of the concrete and to predict tensile stresses in the reinforcement in the vicinity of Cracks. Moreover, this study investigates the influence of reinforcement ratio and compares the results with well-known concrete standards and codes of practice. It is concluded that the non-uniform shrinkage through the thickness of the wall may have significant impact on the cracking behavior of thick concrete walls. In addition, as expected, higher reinforcement ratio results in lower tensile stresses in the reinforcement. The thesis also provides guidelines for minimum reinforcement ratio.

Assessment of Interacting Corrosion Defects in Thin-Walled Pipes

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Ahmed A. Soliman ◽  
Mohammad M. Megahed ◽  
Ch. A. Saleh ◽  
Mostafa Shazly
Keyword(s):  
Nonlinear Finite Element ◽  
Metal Loss ◽  
Test Results ◽  
Defect Depth ◽  
Element Analysis ◽  
Shell Elements ◽  
Codes Of Practice ◽  
Useful Life ◽  
Corrosion Defects ◽  
Interaction Rule

Abstract Corrosion in pipes is usually found in the form of closely spaced defects, which eventually reduce the pipe pressure carrying capacity and piping planned useful life. Codes and standards have been developed to evaluate the effect of such form of metal loss on the piping pressure carrying capacities. However, predictions of such codes are usually conservative, and hence, there is a need to assess their degree of conservatism. The present paper utilizes nonlinear finite element analysis (FEA) in estimating pressure carrying capacities of defective pipes, and hence provides an evaluation of codes degree of conservatism. Shell elements with reduced thickness at the corrosion defect are adopted and their accuracy is assessed by comparison with those of solid elements as well as experimental test results. The influence of defects interaction is investigated by considering two neighboring defects in an inclined direction to each other. The influence of inclination angle, inclined proximity distance between the two defects, and the defect depth to wall thickness ratio are investigated. Comparisons were made with predictions of codes of practice in all cases. Code predictions were found to be conservative compared to FEA results. Furthermore, the interaction rule embedded in the codes for checking for interaction leads to inaccurate predictions for closely spaced defects as it does not include the effect of defect depth.

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