EVALUATION OF AUTOGENOUS SHRINKAGE AND DRYING SHRINKAGE BASED ON BOUND WATER CONTENT OF CEMENTITIOUS MATERIALS

摘要

This study is aimed at quantitatively evaluating autogenous and drying shrinkage of high-strength concrete. To this end, the bound water content of concrete samples both sealed and exposed to drying is measured at different ages and the relationship between autogenous shrinkage strain and bound water content obtained for sealed concrete. Then, assuming that autogenous shrinkage strain depends only on bound water content even under drying conditions, the autogenous shrinkage strain for samples exposed to drying is estimated and drying shrinkage calculated. The calculations by this new method demonstrate that conventional calculations based on the superposition principle overestimate autogenous shrinkage strain under drying, while also giving the percentage contribution of autogenous shrinkage strain to total strain.