Estimation of Depth of Concrete Carbonation

ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

  


Title: Estimation of Depth of Concrete Carbonation

Author(s): R. H. Zhang, T. Nakazawa and F. lmai

Publication: Special Publication

Volume: 170

Issue:

Appears on pages(s): 633-648

Keywords: Carbonation; concretes; diffusion; humidity; size distribution.

Date: 7/1/1997

Abstract:
An analytical expression for estimation of the depth of concrete carbonation is derived by considering that carbonation is controlled by dif-fusion of CO2 in concrete. The depth of concrete carbonation with time is given simply iii terms of the diffusion coefficient of CO2 iii concrete: con-centrat ion of ambient CO2, a n d concent rat ion of carbonat able CaO in the hydration products of cement iii concrete. The diffusion coefficient of CO2 in concrete, which is a function of the volume of empty pores iii concrete, is described and suitably modified. The given expression provides a good explanation for the relationship be-tween the depth of carbonation and the internal microstructure of concrete. The estimated results are compared with some available experimental data and the results of carbonation of a 39-year-old concrete bridge. The expression shows good reliability.