Analytical Model for Corrosion-Induced Crack Width in Reinforced Concrete Structures

2006 ◽  
Vol 103 (4) ◽  
Keyword(s):  
Reinforced Concrete ◽  
Analytical Model ◽  
Crack Width ◽  
Concrete Structures ◽  
Reinforced Concrete Structures

scholarly journals Experimental study of the influence of crack width due to corrosion behaviour using different measurement methods and different exposures

2019 ◽  
Vol 289 ◽  
pp. 08005
Author(s):  
Martin Schneider ◽  
Georg Gardener
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Corrosion Behaviour ◽  
Concrete Strength ◽  
Concrete Structures ◽  
Chloride Ions ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Surface Corrosion ◽  
Potential Mapping

Corrosion of reinforcing steel has a great influence in reducing the lifetime of concrete structures; Carbonation of the concrete pore solution causes surface corrosion on the steel and diffusion of chloride ions through the capillary system of the concrete cover causes pitting corrosion on the steel surface. Corrosion of metals is highly dependent on the environmental conditions. Exposure to chloride ions can be critical to the service life of reinforced concrete structures. The durability of reinforced concrete structures exposed to deicing salt or marine environments can be affected by impact of chloride ions. Detection methods for the rate of corrosion of non-destructive and destructive procedures were analysed. The potential mapping applied on the concrete surface was discussed as a standard method for corrosion detection and will be explained in detail including the application boundaries of the method. It is assumed that the corrosion behaviour of reinforcing steel depends on crack widths. To analyse that, 8 coated and 8 uncoated test samples with different concrete strength classes were used. The concrete objects were exposed to a 3% sodium chloride solution. The corrosion behaviour of reinforcing steel is analysed by using potential mapping with different reference electrodes (Ag/AgCl and Cu/CuSO4). The results show a significant correlation between crack size and protection system on the surface. The maximum crack width with a low indication of corrosion was found to be 0.1 mm.

scholarly journals Volumetric Deformations and Crack Control in Reinforced Concrete Structures

2021 ◽  
Author(s):  
Mahmut Acarcan
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Structural Integrity ◽  
Concrete Structures ◽  
Prediction Equation ◽  
Reinforcement Ratio ◽  
Strain History ◽  
Reinforced Concrete Structures ◽  
Limited Information ◽  
Reinforcement Design

Restraint temperature and shrinkage strains are one of the major reasons for cracking of reinforced concrete. Cracking of concrete reduces structural integrity, initiates or accelerates deterioration mechanisms, causes serviceability problems and may raise aesthetical concerns. Particularly for liquid retaining structures, cracks are vital for structural functionality. Measures must be take to prevent or control crack. In most cases, it may not be feasible to prevent crack formation, but crack width can be controlled by providing sufficient amount of reinforcement. Design guides provide limited information on adequate reinforcement design for temperature and shrinkage cracks in reinforced concrete structures. The Finite Element Method(FEM) was used in order to investigate the crack risk, magnitude of crack width, and adequate reinforcement ratio for controlling cracks within the design specifications. In order to find the thermal and shrinkage strains effect during early ages, computer simulations was performed for hardening concrete. Using the computer program ABAQUS/6.4, incremental numerical analysis technique was implemented that provided realistic simulation of stress/strain history. Considering an appropriate value for thermal and shrinkage strains, a parametric study was carried out to estimate the reinforcement ratio for fixed base walls. The crack width was estimated based on the calculated steel stress and the ACI 318-02 crack prediction equation. With consideration of ACI 350-01 specification for allowable crack width, the required amount of reinforcement ratio for various wall dimensions was recommended.

Prediction of Crack Width of Chloride Contaminated Reinforced Concrete Structures

2006 ◽  
Vol 302-303 ◽  
pp. 610-617
Author(s):  
Jia Jin Zheng ◽  
Xin Zhu Zhou ◽  
Shi Lang Xu
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Corrosion Rate ◽  
Crack Width ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Cover Depth ◽  
Steel Bar ◽  
Bar Diameter ◽  
Chloride Contaminated

Crack width is a significant parameter for assessing service life of reinforced concrete structures in chloride-laden environments. Corrosion-induced concrete cracking is a predominant causal factor influencing premature degradation of reinforced concrete structures, incurring considerable costs for repairs and inconvenience to the public due to interruptions. This gives rise to the need for accurate prediction of crack width in order to achieve cost-effectiveness in maintaining serviceability of concrete structures. It is in this regard that the present paper attempts to develop a quasi-brittle mechanical model to predict crack width of chloride contaminated concrete structures. Assuming that cracks be smeared uniformly in all directions and concrete be a quasi-brittle material, the displacement and stress in a concrete cover, before and after surface cracking, were derived respectively in an analytical manner. Crack width, as a function of the cover depth, steel bar diameter, corrosion rate and time, was then determined. Finally, the analysis results were verified by comparing the solution with the experimental results. The effects of the cover depth, steel bar diameter and corrosion rate on the service life were discussed in detail.

Calculation of the Minimum Reinforcement for Limitation of Crack Width According to Change of National Annex for ČSN EN 1992-1-1

2015 ◽  
Vol 1106 ◽  
pp. 217-220
Author(s):  
Jiří Šmejkal ◽  
Jaroslav Procházka
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Concrete Structures ◽  
Maximum Distance ◽  
Reinforced Concrete Structures ◽  
Optimal Amount ◽  
Minimum Reinforcement ◽  
Concrete Elements

Design of minimum reinforcement for concrete elements with regard to width of cracks is important for consumptions of steel. Optimal amount of reinforcement shall ensure that cracks, which are typical for reinforced concrete structures, will be small that the serviceability and durability will be not influenced. One of most important parameter for crack width is the maximum distance between cracks. The information connecting with various procedures for design and minimum reinforcement with regard to width of cracks are given in this article.

scholarly journals Bond Deterioration of Corroded-Damaged Reinforced Concrete Structures Exposed to Severe Aggressive Marine Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Cecielle N. Dacuan ◽  
Virgilio Y. Abellana
Keyword(s):  
Reinforced Concrete ◽  
Bond Strength ◽  
Crack Width ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Minimal Amount ◽  
Reinforced Concrete Structures ◽  
Exponential Relationship ◽  
Cross Sectional ◽  
Different Diameters

Cracks lead to a reduction of the bond between concrete and reinforcing steel rebars. A considerable decrease in the bond strength is more dangerous to a structural element’s safety than the loss of the cross-sectional steel reinforcement area. The purpose of this study is to evaluate the bond strength of corroded-damaged structures exposed to severely aggressive marine environments. Eighteen (18) cube specimens with dimensions of 200   mm   x   200   mm were cast. They were reinforced with three (3) different diameters of deformed steel and were grouped as unconfined and confined. The specimen was accelerated under a simulated corrosive environment. The experiment results reveal that the bond strength of concrete and steel reinforcement is susceptible to corrosion levels. The degree of corrosion significantly affects the bond strength of concrete and steel. The bond strength and the average crack width have a strong correlation; a minimal amount of corrosion with a minimum crack width of 0.03 mm after cracking reduces the bond strength to an unacceptable level. Stirrups confinement has a significant influence on the bond strength; it provides an excellent means to counteract bond loss. The loss of bond directly affects the serviceability and ultimate strength of reinforced concrete structures. There is an exponential relationship between cement and steel reinforcement’s bond strength with the serviceability and residual strength of reinforced concrete structures.

scholarly journals Comments concerning crack width calculation in joints of steel-concrete composite slabs

2014 ◽  
Vol 13 (3) ◽  
pp. 111-118
Author(s):  
Michał Knauff ◽  
Marcin Niedośpiał
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Type B ◽  
Tension Stiffening ◽  
Type D ◽  
Composite Slabs ◽  
Code Type ◽  
Crack Widths

In this paper some aspects of the calculation of the width of cracks in joints of steel-concrete composite slabs are reported. The code concerning design of composite steel and concrete structures for the calculation of crack widths refers to the code of reinforced concrete structures. The application of the formula, which takes into account „tension stiffening”, seems to lead to surprising results - for the elements with small reinforcement ratio, the obtained stress is much greater than the stress calculated in classical way i.e. without tension stiffening. The authors present the derivation of this formula - the result corresponds to the formula in the code but in the paper an additional case is taken into account. Furthermore, the authors suggest to consider two types of areas as in the RC code. Type D (D from "discontinuity") should be analyzed in the close surrounding of the column and type B (B from Bernoulli) areas at some distance from the column.

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