Development of a new combined corrosion protection system for chloride-contaminated reinforced concrete structures

2005 ◽  
Vol 56 (2) ◽  
pp. 104-110 ◽  
Author(s):  
J. Mietz ◽  
A. Burkert ◽  
G. Eich ◽  
M. Raupach
2009 ◽  
Vol 15 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Zenonas Kamaitis

Various protective barriers are used in practice to protect reinforced concrete structures in severely aggressive environments. In this paper, we consider a multi‐component corrosion protection system (CPS), taking into account the performance of protective surface barrier, concrete cover and steel reinforcement, which is modelled as a three‐unit of non‐identical components cold standby system. The system is non‐maintained. This is the case when the system is not easily accessible for repair, repair; is time‐consuming and costly. In this system it is assumed that degradation rates of all components are exponential and different. Under these assumptions, using the Markovian degradation process, some important reliability indices such as the system reliability and mean time to failure are defined. In addition, we present simulation results to substantiate the analytical model and to demonstrate the sensitivity analysis to estimate protection system reliability. Santrauka Įvairios apsauginės dangos naudojamos gelžbetoninėms konstrukcijoms stipriai agresyvioje aplinkoje apsaugoti. Straipsnyje nagrinėjama daugiasluoksnė antikorozinė apsauga, susidedanti iš apsauginio barjero, betoninio apsauginio sluoksnio ir plieninės armatūros. Sistema modeliuojama kaip trijų nevienodų komponentų šaltai rezervinė sistema. Ši sistema yra neremontuojama. Tai atvejai, kai sistema sunkiai pasiekiama, remontas ilgai trunka arba brangus. Tariama, kad sistemos visų komponentų irimo intensyvumas yra eksponentinis ir skirtingas. Remiantis šiomis prielaidomis, naudojant Markovo suirties (atnaujinimo) teoriją, kai kurie svarbūs patikimumo rodikliai, tokie kaip sistemos patikimumas ir vidutinis laikas iki suirties, gali būti nustatyti. Skaitinis pavyzdys iliustruoja analitinio modelio taikymą ir jo jautrumą vertinant antikorozinės apsauginės sistemos patikimumą.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Alexander Bulkov ◽  
Michail Baev ◽  
Igor Ovchinnikov

The influence of reinforcing steel corrosion on the durability of reinforced concrete structures of transport structures and the degree of knowledge of this problem is considered. It is specified that the protection of reinforcing steel from corrosion is not able to completely replace the correct design and use of high-strength concrete. But it is able to extend the life of reinforced concrete structures. It is noted that corrosion of the reinforcement leads to a decrease in the structural strength due to wear and tear and by a third of the period of operation of reinforced concrete structures, as a result of which transport structures collapse. As an example of the detrimental effect of corrosion of reinforcing steel on the durability of transport structures, examples of accidents of bridges and overpasses caused by this type of corrosion are given. As a result, a conclusion is drawn on the advisability of ensuring a sufficient level of corrosion protection of reinforcing steel to achieve the required durability of reinforced concrete structures of transport structures. The types and causes of corrosion processes in reinforcing steel reinforced concrete structures are described. The compositions and technologies of anticorrosive protection are examined and analyzed. Comparison of the compositions of anticorrosive protection of reinforced concrete structures is carried out according to the following criteria: consumption, density, viability, curing temperature and the number of components of the composition. A comparison of anti-corrosion protection technologies is carried out on the basis of the following indicators: line dimensions, productivity and consumption of energy resources. A comparison is also made of the cost of using various anti-corrosion protection technologies. Based on the data obtained, the advantages and disadvantages of the considered compositions and technologies of corrosion protection are determined. As a result, the most effective and technologically advanced method of corrosion protection of steel reinforcement of reinforced concrete structures of transport structures is selected.


2006 ◽  
Vol 302-303 ◽  
pp. 610-617
Author(s):  
Jia Jin Zheng ◽  
Xin Zhu Zhou ◽  
Shi Lang Xu

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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