Tests to evaluate the compressive strength, tensile strength and static modulus of elasticity of concretes containing various levels of condensed silica fume (CSF) (microsilica) substitutions for Portland cement were conducted at two water curing temperatures. I was found that CSF replacements for cement of up to 28% can have a beneficial effect on the compressive strength. Although high-temperature curing (50°C) accelerates the strength development at early ages, the 91 day strength does not appear to be influenced by temperature. The curing temperature does not affect the observed relationships between the tensile strength, the modulus of elasticity and the compressive strength, There is a marked reduction in the elasticity modulus at the higher levels of CSF substitutions for cement.