Comparison of Compressive, Tensile, and Flexural Creep of Early-Age Concretes under Sealed and Drying Conditions

Abstract

The compressive creep of concrete is normally adopted to predict the stress or the time-dependent deformation of concrete members, without considering the difference of creep under different loading types, i.e., compressive, tensile, and flexural loads. This will inevitably lead to inaccurate prediction of stress and deformation, particularly at early ages when creep effect is pronounced. This study conducts a systematic creep comparison for early age concrete under different loading types and curing conditions. Three types of creep devices are developed for compressive, tensile, and flexural creep measurements of concrete under both sealed and drying conditions. Low-strength and high-strength concretes with water:cement (w/c) ratios of .3, .4, and .5 are tested at the age of 7 days. The measured creep is compared in terms of loading types and curing conditions (sealed versus drying). The ratios of different types of creep are quantified and compared with the literature. The rationality of using compressive creep to substitute tensile or flexural creep is justified. The results of this study provide quantitatively the creep difference under different conditions, which helps to gain confidence about the predicted stress and the strain when different creep models are used.