[en] In Belgium, a number of girder bridge deck slabs have over the past several years been displaying major degradations (delamination, disaggregation, etc.) capable, in time, of leading to slab perforation. This form of degradation, called "rotting of bridge deck slab concrete" is not uniformly distributed over the deck surface: deteriorated zones can be distinguished from intact zones and moreover are often associated with the presence of dark spots. On the lower surface of some such spots, the previously-carbonated concrete layer can sometimes once again display a pH of above 8.3. It will also be demonstrated that this anomaly may be attributed to a migration of alkaline through the concrete slab towards the lower surface, thereby causing a re-alkalinization of the carbonated layer and hence a rise in pH.
Disciplines :
Materials science & engineering
Author, co-author :
Darimont, Anne ; Université de Liège - ULiège > Département Argenco : Secteur GeMMe > Matériaux et maintenance en construction
Gilles, Pierre
Dondonne, E.
Language :
English
Title :
Re-alkalinization of carbonated concrete by means of alkaline migration
Alternative titles :
[fr] Réalcalinisation du béton carbonaté par migration des alcalins
Publication date :
June 2006
Journal title :
Bulletin des Laboratoires des Ponts et Chaussées
ISSN :
1269-1496
Publisher :
Laboratoire Central des ponts et Chaussees, France
POURBAIX M., Leçons en corrosion électrochimique, Centre belge d'étude de la corrosion - CEBELCOR, 1975, 377 pages.
DEMARS Ph., GILLES P., DONDONNE E., DEGEIMBRE R., DARIMONT A., LORENZI G., MERTENS A., Dégradation de dalles de tablier de ponts en Belgique - Étude d'une pathologie complexe, Bulletin des laboratoires des ponts et chaussées, 232, 2001, pp. 73-83.
Carbonatation depth in hardened concrete, prEN 14630, 2003.
PERRY J.H., Chemical Engineers'handbook, McGraw-Hill Book Company Edition, 1950, p. 284.
Analyse chimique des mortiers et bétons durcis, NBN B15-250, 1991.
Adjuvants pour bétons, mortiers et coulis Méthode d'essai - Partie 10: Détermination de la teneur en chlorure soluble dans l'eau, NBN EN 480-10, 1996.
MACLEOD G., HALL A.J., FALLICK A.E., An applied mineralogical investigation of concrete degradation in a major concrete road bridge, Mineralogical Magazine, 54, 1990, pp. 637-644.
CHAROLA A.E., LEWIN S.Z., Efflorescences on building stones - SEM in the characterisation and elucidation of the mechanisms of formation, Scanning Electron Microscopy, 1, 1979, pp. 379-386.
GUTHRIE G.D., CAREY J.W., A geoscience approach to rock-solid concrete. Earth and Environmental Sciences, Progress report 1998-2000, pp. 34-37.
