Title: Performance Characteristics of Concrete Incorporating A Natural Amorphous Silica

Author(s): D.H.Chisholm

Publication: Symposium Paper

Volume: 171

Issue:

Appears on pages(s): 271-296

Keywords: Abrasion; chemical properties; compressive strength; durability; pozzolans; silica.

DOI: 10.14359/6101

Date: 8/1/1997

Abstract:
A natural amorphous silica with a purity of approximately 90% is mined from an extensive geothermal deposit near Rotorua, New Zealand. After refining and processing to remove impurities, the ‘Microsilica 600TM’ has properties which comply with Australian Standard AS 3582 Part 3 ‘Silica Fume’ as a supplementary cementitious material for use with portland cement. The performance characteristics of concrete incorporating the ‘Microsilica 600’ were evaluated at two cement levels of 320 and 400 kg/m 3 and two silica addition levels of 7 and 10%. Properties evaluated were compressive strength, tensile strength, concrete shrinkage, sulfate resistance, resistance against chemical attack, abrasion resistance, and chloride permeability. Performance improvement compared favorably with published data on concretes incorporating processed ‘conventional’ silica fume.