Crack Width Evolution of R/C Structures Subject to Corrosion and Fatigue

Corrosion modifies the steel-concrete interface in reinforced concrete structures. Moreover in structures subjected to cyclic load, a simultaneous mechanical deterioration due to the load is present. Both phenomena can lead to an evolution of cracks width during the service life. In order to evaluate the crack openings increase, an experimental campaign on reinforced concrete ties subjected to simultaneous loading and corrosion have been realized. Transversal crack opening, initially due to loading and longitudinal corrosion cracks evolution is monitored. Results highlight the differences in terms of corroded and uncorroded specimens, static and cycling test and also different loading amplitude. Finally it can be observed as the growing of the damage is significantly different when a cycling action, combined with a chemical attack is present.

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Experimental Evaluation of Corrosion Effect on Bond Between Steel and Concrete in Presence of Cyclic Action

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.417-418.345 ◽

2009 ◽

Vol 417-418 ◽

pp. 345-348 ◽

Cited By ~ 2

Author(s):

Luca Giordano ◽

Giuseppe Mancini ◽

Francesco Tondolo

Keyword(s):

Reinforced Concrete ◽

Cyclic Load ◽

Crack Opening ◽

Concrete Structures ◽

Electrochemical Corrosion ◽

Reinforced Concrete Structures ◽

Reinforcing Bars ◽

Cyclic Action ◽

In Series ◽

Ultimate Condition

Corrosion modifies the steel-concrete interface in reinforced concrete structures. The efficiency of the connection between the two materials is reduced and the structural behavior both in service and in ultimate condition is affected. Moreover in structures subjected to cyclic load, a simultaneous mechanical deterioration due to the load is present. In this work an experimental analysis on reinforced concrete structures under both cyclic load and corrosion of reinforcing bars is presented. Three couples of reinforced concrete ties are connected in series and subjected to the same stress variation in order to produce the cracking conditions and to activate the bond mechanism. However, while one of the two reinforced concrete ties is only subjected to cyclic load, the second one is also corroded using an accelerated electrochemical corrosion process. The simultaneous effect of the cyclic load and corrosion is evaluated monitoring the crack opening on the structures during the test and by means of visual inspection of the sample. The test results show the correlation between the mechanism of bond and the average level of stresses for an amplified stress range.

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Prediction of Crack Width of Chloride Contaminated Reinforced Concrete Structures

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.302-303.610 ◽

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.

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