Title: Efficiency Factors for Condensed Silica Fume in Concrete

Author(s): Magne Maage

Publication: Symposium Paper

Volume: 114

Issue:

Appears on pages(s): 783-798

Keywords: carbonation; compressive strength; concretes; durability; permeability; silica fume; Materials Research

DOI: 10.14359/2385

Date: 5/1/1989

Abstract:
The term "efficiency factor" for condensed silica fume in concrete can be defined as the number of parts of cement that may be replaced by one part of silica fume without changing the property studied. This factor was first introduced for concrete compressive strength after 28 days curing in water at 20 C. In this situation, factors around 3 to 4 are reported. However, if the concrete is exposed to other temperatures, other curing conditions, or other curing periods, the factor may be as low as zero. This is very important information for the practical application of silica fume, especially when forms have to be stripped very early in winter concreting. The durability of concrete structures is more in focus than ever. When studying durability, the efficiency factors of silica fume in concrete can be calculated at the same time. Durability efficiency factors are also affected by the curing conditions. A comprehensive research program has enabled efficiency factors to be calculated for different conditions. This has covered strength and durability parameters such as permeability, carbonation, and chloride penetration. This work will be a helpful indication of how silica fume can be used in the most efficient way in concrete structures.