Title: Quality of Cover Concrete and its Influence on Durability

Author(s): R. J. Potter and D. W. S. Ho

Publication: Symposium Paper

Volume: 100

Issue:

Appears on pages(s): 423-446

Keywords: carbonation; concrete durability; corrosion; cover; curing; reinforced concrete; reinforcing steels; sorption; General

DOI: 10.14359/3595

Date: 4/1/1987

Abstract:
Durability distress in the external surfaces of buildings is related to the corrosion of reinforcement. The controlling parameters for this distress are the quality of the cover concrete and the depth of cover. The quality of the cover concrete is evaluated in terms of carbonation resistance and water sorptivity. It is found that of the factors examined in the research program the major one is the length of initial continuous curing received by the concrete. It is concluded that it is doubtful if exposure to weather, especially in typical Australian climates, will enable cover concrete on the facades of buildings to achieve its potential protection capability. Short-term tests suggest that the resistance to carbonation is increased by increasing the strength of the concrete, using water reducers, and decreasing the amount of fly ash in the mix. The water sorptivity may be reduced by either increasing the strength of the concrete and/or increasing the initial curing period. 613-387