Title: Silica Fume in High-Strength Concrete

Author(s): V. Yogendran, B. W. Langan, M. N. Haque, and M. A. Ward

Publication: Materials Journal

Volume: 84

Issue: 2

Appears on pages(s): 124-129

Keywords: air-entrained concretes; compressive strength; flexural strength; freeze-thaw durability; high-strength concretes; plasticizers; silica; water-cementitious ratio; Materials Research

DOI: 10.14359/1848

Date: 3/1/1987

Abstract:
The efficiency of silica fume in influencing the strength of high-strength concrete was studied at different water-cementitious ratios and dosages of silica fume. The results suggest that the optimum replacement of cement by silica fume in high-strength concrete 50 to 70 MPa (7500 to 10,500 psi) at 28 days is 15 percent. Furthermore, the effect of silica fume decreases with increasing cement content and decreasing water-cementitious ratios. At a cement content of 500 kg/m3 (840 lb/yd3) and a water-cementitious ratio of 0.28, it was not possible to increase the strength of concrete using silica fume to replace cement. In addition, normal levels of air entrainment were required even in the highest strength mix to insure adequate performance in rapid freeze-thaw testing.