Title: Mechanical and Durability-Related Properties of High-Strength Concrete Containing Silica Fume

Author(s): K. Torll and M. Kawamura

Publication: Symposium Paper

Volume: 149

Issue:

Appears on pages(s): 461-474

Keywords: carbonation; chloride ions; compressive strength; freeze-thaw durability; high-strength concretes; permeability; porosity; silica fume; splitting tensile strength; Materials Research

DOI: 10.14359/4094

Date: 10/1/1994

Abstract:
Report presents the data on the effects of silica fume on mechanical and durability-related properties of high-strength concrete. High-strength concrete had a compressive strength in the range of 90 to 100 MPa. The compressive strength of high-strength concrete containing 8 percent silica fume was 25 to 30 percent higher than that of a corresponding concrete without silica fume. Both the splitting tensile strength and the modulus of elasticity of high-strength concrete increased as the compressive strength increased, but at a slower rate. The pore structure both in the cement paste and at the cement paste-aggregate interface in high-strength concrete containing 8 percent silica fume was very dense and homogenous due to the microfiller and pozzolanic effect of silica fume, leading to an improvement of the bond between cement paste and aggregates. Durability-related properties such as the chloride-ion permeability, the resistance to freezing-thawing, and the depth of carbonation of high-strength concrete with and without silica fume were also investigated with a special interest in the influence of curing condition at early ages on their properties. From the results, it was found that the use of silica fume in high-strength concrete led to a significant improvement of chloride-ion permeability, and no negative influence on the carbonation. However, the resistance of non-air-entrained high-strength concrete with and without silica fume to the freezing and thawing cycles was very sensitive to the lack of moist curing at early ages, and a poorly cured nonAE high-strength concrete containing 8 percent silica fume deteriorated more seriously.