Title: Properties and Durability of Alkali-Activated Slag Concrete

Author(s): E. Douglas, A. Bilodeau, and V. M. Malhotra

Publication: Materials Journal

Volume: 89

Issue: 5

Appears on pages(s): 509-516

Keywords: air entrainment; alkalies; blast furnace slag; chloride ions; compressive strength; flexural strength; freeze-thaw durability; shrinkage; modulus of elasticity; Materials Research

DOI: 10.14359/1832

Date: 9/1/1992

Abstract:
Formulates the proportioning of concrete mixes made with ground granulated blast furnace slag activated with sodium silicate, and determines their properties and durability. Six mixes were made with a solution having silicate modulus Ms = 1.47 and one mix with sodium silicate of Ms = 1.22. All the mixes were air-entrained. Compressive and flexural strengths, Young's modulus of elasticity, shrinkage, and chloride ion penetration were determined. Measurements of length and mass changes, as well as resonant frequency and pulse velocity, were performed to evaluate the resistance of the concretes to repeated cycles of freezing and thawing. Sulfate resistance was evaluated by the same technique. The study shows that air content, volume of air-entraining admixture, slump, and early-age compressive strength are affected by the sodium silicate-slag ratio. Compressive and flexural strengths of the concretes at 7 days and beyond are comparable to or better than those of a portland cement concrete with equivalent water-cement ratio and workability. Drying shrinkage and expansion shrinkage strains were higher than those of a comparable portland cement concrete. Low-sodium silicate-slag ratios adversely affected the resistance to repeated freezing and thawing cycles but improved the resistance to chloride ion penetration. Longer term test measuremnts are necessary to evaluate the resistance of the concretes to sulfate attack.