As the first of its kind, this book presents a balanced view of the effect of condensed silica fume on the physical, chemical, mechanical, and durability aspects with respect to cement paste, mortar, and concrete. It discusses the nature and types of condensed silica fume, physical characteristics, product variation and problems involved in its handling and transportation.

This report provides a comprehensive review of the properties of concrete containing condensed silica fume(CSF) at each stage of hardening, emphasizing the improvements gained in durability.

The properties of hydraulic cement concretes containing silica fume were investigated to assess their suitability for use in overlays with s minimum thickness of 1 1/4 in. The properties studied were compressive and flexural strengths, bond strength, modulus of elasticity, permeability, freeze-thaw resistance, thermal expansion, and drying shrinkage. The characteristics of sir voids in the hardened concrete were determined by petrographic examination. The study was conducted in two stages: the first to determine the mixture proportions that would yield satisfactorily high strengths and low permeabilities, and the second to conduct the main testing program. Silica fume from two sources was used. Concretes made with silica fume from either source at a water-cement ratio of 0.40 or lower and s replacement rate of 5% yielded the desirable properties. It is expected that concretes made with silica fume can provide a cost-effective protective system for bridge decks when placed in overlays with s minimum thickness of 1 1/4 in.