The strength development of silica fume concrete and its prediction under varying temperature conditions

The strength development of three silica fume concrete (SFC) mixes under the changing temperature conditions in a newly cast lining of a mine shaft has been investigated. A temperature matched curing rig has been improved for simulating different temperature regimes. The strength predictions of the SFC under changing temperature regimes show good agreement with test results, but adjustment of the empirical activation energy at high temperatures is necessary. The relationship between early-age splitting and cube compressive strength has been examined and was found to be different from that for conventional concrete due to the two-stage pattern of strength development of the silica fume plus superplasticizer concrete. Mixes involving two forms of silica fume, namely densified and commercially slurrified, are tested, and no notable dlfference has been found.