History and Status of Specifications and Tests for Strength

Strength specifications and test methods over the past 75 years of cement testing are reviewed. Early strength specification ranges and limits, requiring tensile strength tests of neat cement paste and mortar briquets, have evolved into compressive strength specifications, using mortars prepared and tested in accordance with detailed test methods. Though present strength specifications appear adequate, new cementitious materials and research test methods will, no doubt, produce a need for new test methods and specifications, which will include other considerations, such as uniformity.