ELASTIC-MODULUS, POISSON RATIO, AND COMPRESSIVE STRENGTH RELATIONSHIPS AT EARLY AGES

Presents the results of an experimental investigation into the relative relationships between the elastic modulus, Poisson's ratio, and the cylinder compressive strength of concrete, especially at early ages. The applicability to concrete at early ages of some of the existing relations between these properties was also examined. Tests were performed on four different concrete mixes using conventional 6 x 12-in. Cylinders. Test results were obtained for ages ranging from 6 hr to 28 days. Analyses of test results show that the compressive strength and the elastic modulus are related, and an increase in one is, in general, similarly reflected in an increase in the other. The commonly accepted relationship that the elastic modulus of concrete is proportional to the 0.5 power of the cylinder compressive strength was found to be accurate for the elastic modulus at ages 12 hr and above for all concrete mixes investigated. Poisson's ration was found to be insensitive to both the age and the richness of concrete mix and did not change appreciably with compressive strength development.