Volume 6, Issue 3 (March 2009)
Relationships Between Key ASTM Test Methods Determined on Concrete and Concrete-Equivalent-Mortar Mixtures
Concrete batching requires considerable amounts of materials, energy, and time for testing. This highlights the importance of using alternative easier approaches based on mortars to simplify and speed up the experimental testing programs. This paper seeks to establish relationships between responses of ASTM Test Methods conducted on concrete and concrete-equivalent-mortar (CEM). Different series of mixtures having various cement contents of 300, 350, 400, and 450 kg/m3 and water-to-cement ratios of 0.4, 0.45, 0.5, 0.55, and 0.6 were tested. Test results showed that the CEM approach can adequately predict the slump, slump variations, water reduction, air content, setting time, and compressive strength of concrete with coefficients of correlation (R2) greater than 0.86. Conversely, moderate relationships were obtained when correlating the flexural strength and length change responses of concrete to those determined on CEM. This was mainly attributed to variations in the specimen dimensions and effect of the interfacial transition zone resulting from the presence of coarse aggregates.