Title: Strength and Durability of Slag-Gypsum Cement Concrete

Author(s): Taketo Uomoto and Kazusuke Kobayashi

Publication: Symposium Paper

Volume: 79

Issue:

Appears on pages(s): 1013-1038

Keywords: blast furnace slag; blended cements; carbonation; compressive strength; concrete durability; corrosion; deterioration; gypsum; protective coatings; reinforced concrete; reinforcing steels; supersulfated cement.

DOI: 10.14359/6737

Date: 5/1/1983

Abstract:
If a cement consisting mostly of blast-furnace slag and by-product gypsum becomes practical, it will not only contribute to energy saving, but will also result in the effective use of resources and industrial wastes. This report mainly investigates by experimentation the strength characteristics, surface deteriora-tion of the cement concrete and corrosion of reinforcing steel when using the above cement. The major findings of this research are: 1) The relation between compressive strength and water-cement ratio differs from that of ordinary portland cement and varies greatly depending on the degree of mixing. A general strength formula for this type of cement concrete is proposed. 2) The surface deterioration of the cement concrete, caused by carbon dioxide in the air, cannot be prevented by changing the proportion of cementing materials without changing other proper-ties. The most practical method is to apply coatings to the sur-face of concrete. 3) A fairly large amount of corrosion is observed on the surfaces of reinforcing steel in concrete at the age of four weeks. It is considered that the cause is the reaction productpf slag and gypsum, and inhibitor is effective in preventing corrosion.