Estimation of the Amount of Chloride Ingress in Concrete Taking Into Account Differences in the Amount of Adhering Salt on Bridge Members

<p>While concrete structures perform well in many situations, lack of durability has emerged as a significant issue for asset owners. A review of past bridge failures was done to identify the most probable causes of bridge failures. This study has tended to focus on current models used for estimating the time to deterioration of concrete bridges instigated by Chloride ingress and Fatigue. Subsequently, mathematical modelling of the best-suited deterioration model is done to arrive at the residual life of two existing bridges. This work has highlighted high variability in the parameters used to describe the durability related properties of in-situ aged concrete. A realistic residual life assessment can be achieved by correct evaluation of these parameters by periodic testing of bridge samples</p>

Download Full-text

Leaching, carbonation and chloride ingress in reinforced alkali-activated fly ash mortars

MATEC Web of Conferences ◽

10.1051/matecconf/201819902025 ◽

2018 ◽

Vol 199 ◽

pp. 02025 ◽

Cited By ~ 1

Author(s):

Gregor J. G. Gluth ◽

Petr Hlaváček ◽

Steffi Reinemann ◽

Gino Ebell ◽

Jürgen Mietz

Keyword(s):

Fly Ash ◽

Visual Inspection ◽

Electrochemical Behaviour ◽

Transport Coefficients ◽

Chloride Penetration ◽

Chloride Ingress ◽

Reaction Products ◽

Steel Bars ◽

Alkali Activated Binders ◽

Alkali Activated

Alkali-activated fly ash mortars were studied with regard to durability-relevant transport coefficients and the electrochemical behaviour of embedded carbon steel bars on exposure of the mortars to leaching, carbonation and chloride penetration environments. The transport coefficients differed considerably between different formulations, being lowest for a mortar with BFS addition, but still acceptable for one of the purely fly ash-based mortars. Leaching over a period of ~300 days in de-ionized water did not lead to observable corrosion of the embedded steel, as shown by the electrochemical data and visual inspection of the steel. Exposure to 100 % CO2 atmosphere caused steel depassivation within approx. two weeks; in addition, indications of a deterioration of the mortar were observed. The results are discussed in the context of the different reaction products expected in highand low-Ca alkali-activated binders, and the alterations caused by leaching and carbonation.

Download Full-text

Sensor-based time-dependent formation factor in prediction of chloride ingress in mortar

Magazine of Concrete Research ◽

10.1680/jmacr.18.00150 ◽

2019 ◽

Vol 71 (22) ◽

pp. 1180-1192 ◽

Cited By ~ 2

Author(s):

Milena Rangelov ◽

Somayeh Nassiri

Keyword(s):

Time Dependent ◽

Chloride Ingress ◽

Formation Factor

Download Full-text

Damage of Reinforced Concrete Structures due to Steel Corrosion

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1111.187 ◽

2015 ◽

Vol 1111 ◽

pp. 187-192

Author(s):

Corina Sosdean ◽

Liviu Marsavina ◽

Geert de Schutter

Keyword(s):

Reinforced Concrete ◽

Building Materials ◽

Structural Integrity ◽

Colorimetric Method ◽

Concrete Structures ◽

Steel Corrosion ◽

Degradation Process ◽

Reinforced Concrete Structures ◽

Chloride Ingress ◽

Rc Structures

Reinforced concrete (RC) became one of the most widely used modern building materials. In the last decades a great interest has been shown in studying reinforcement corrosion as it became one of the main factors of degradation and loss of structural integrity of RC structures. The degradation process is accelerated in the case of RC structures situated in aggressive environments like marine environments or subjected to de-icing salts. In this paper it is shown how steel corrosion of the embedded rebars occurs and how this affects the service life of reinforced concrete structures. Also, an experimental study regarding the combined effect of carbonation and chloride ingress was realized. Samples with and without rebars were drilled from a RC slab which was stored in the laboratory for two years. Non-steady state migration tests were realized in order to determine the chloride profile, while the carbonation depth was measured using the colorimetric method based on phenolphthalein spraying. It was concluded that carbonation has a significant effect on chloride ingress, increasing it.

Download Full-text