Constitutive Model for Predicting Ultimate Drying Shrinkage of Concrete

Abstract

A constitutive model is derived from theory of elasticity for predicting ultimate drying shrinkage of concrete. The model was extended by incorporating the semiempirical composite model proposed by Hirsch and Dougill for predicting Young's modulus of concrete. Their composite model is the geometric mean of Paul's upper and lower limit boundaries of a two‐phase composite. According to the shrinkage model the parameters needed for predicting ultimate drying shrinkage of concrete at any relative humidity of drying are the following: ultimate shrinkage of a paste of same water‐to‐cement (W/C; ratio and degree of hydration as the concrete, relative volume of aggregates and unhydrated cement, and the elastic properties of hydrated paste and the particles. The shrinkage model was tested on shrinkage results obtained in this study and by Pickett. Three different W/C ratios were covered together with a wide range in aggregate contents. Excellent agreement with the results was found.