Hostname: page-component-77c89778f8-m42fx Total loading time: 0 Render date: 2024-07-20T00:11:36.903Z Has data issue: false hasContentIssue false

Effect of the ITZ Damage on Durability of Reinforced Concrete in Chloride Environment

Published online by Cambridge University Press:  21 February 2011

Raoul François
Affiliation:
LMDC INSA-UPS Génie Civil, complexe scientifique de Rangueil, 31077 Toulouse CEDEX, France
Ginette Arliguie
Affiliation:
LMDC INSA-UPS Génie Civil, complexe scientifique de Rangueil, 31077 Toulouse CEDEX, France
Get access

Abstract

This paper deals with the effect of the ITZ on the service life of reinforced concrete. In the case of reinforced concrete structures, the penetration of chlorides does not depend only on concrete transfer properties but also on the loading applied, on the state of strains and on the exposure to the aggressive environment.

In order to take into account these different parameters, we have performed experiments on reinforced concrete elements, over a long period. The samples used have to be of an adequate size (3 meters long) and stored in a salt fog in a loading state so as to be representative of the actual operating conditions of the reinforced concrete structures.

The bending of the beams leads to the development of cracks which are neither preceded nor accompanied by microcracks, but the cement paste-aggregate interfaces are damaged in the tensile areas.

The service loading of reinforced concrete has two consequences : firstly, a cracking with widths ranging between 0.05 mm and 0.5 mm according to the intensity of the mechanical strength applied. Secondly, a damage of the ITZ in the tensile areas causing an increase of chloride penetration directly proportional to the intensity of the stress applied to the beam.

The model of the development of corrosion, worked out in relation with time and based on our results, emphasizes the influence of the paste-aggregate interface damage on the duration of the service life.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. French Regulations for Reinforced Concrete Structures - BAEL 83Google Scholar
2. François, R., Maso, J-C. - Effect of damage in reinforced concrete on carbonation or chloride penetration, Cement and Concrete Research, Vol. 18, pp. 961970, 1988.Google Scholar
3. François, R., Maso, J-C. - Etude de la microfissuration de poutres en béton armé sollicitées en flexion simple, Annales de I'I.T.B.T.P. n°464 - mai 1988.Google Scholar
4. François, R., Arliguie, G. - Durability of loaded reinforced concrete in chloride environment, Third CANMET/ACI International Conference on Durability of Concrete. SP145-30, Nice 05/1994.Google Scholar
5. Tuutti, K. - Corrosion of steel in concrete, CBI reseach report 4, 1982.Google Scholar