Durability and Performance of Indigenous Amorphous Silica in Advanced Cementitious Systems

Microsilica 600 (MS60) is a highly reactive pozzolan processed from a natural white geosilica deposit found in New Zealand’s Rotorua district. Like silica fume it is a very fine amorphous silica and falls into the microsilica family of products. As part of a feasibility study of using MS600 in the manufacturing process of Golden Bay Cement, this work establishes the improved performance characteristics that can be achieved with MS600 When added with Portland cement, MS600 facilitates high performance concrete by achieving: increased compressive strength, improved sulphate resistance, reduced alkali silica reactity, very low chloride diffusion, reduced water permeability, improved abrasion resistance. improved resistance to chemical attack, improved stability in geothermal environments, superior plastic properties (moderate concrete bleed, lower heat generated, high quality finish) and low drying shrinkage characteristics. It has been shown that MS600 will satisfy performance requirements in applications requiring an advanced concrete material having long serviceability in harsh environments or where structural performance beyond current limitations are pre-requisites.