Evolution of temperature, humidity and deformation in early-age cement-based materials based on a multi-field model

Abstract

Early-age cement-based materials undergo significant physical and chemical changes and have a complex mutual relationship among their temperature, humidity and mechanical behavior. As the second part of this study, this paper builds a multi-field coupling equation model taking into account the staged characteristics of the deformation for early-age cement-based materials based on the Hybrid Mixture Theory, and the accuracy of calculation results are verified with the test results obtained in the first part of this study. Moreover, the multi-field coupling model has been adopted to simulate the evolution of the different types of deformation for early-age cement-based materials. The results show that the multi-field coupling model established in this paper and the staged deformation calculation model established for early-age cement-based materials in the first part of this study can be used to better describe the development of their early-age temperature, humidity and deformation. Moreover, thermal strain is the earliest deformation that may cause cracking of cement-based materials, and chemical shrinkage has a certain compensation effect on thermal strain. In addition, the coefficient of thermal expansion (CTE) and the coefficient of stiffness influence (CSI) as well as their effects on thermal and chemical deformations have been analyzed. The results of this study can provide an important reference for analyzing the performance evolution of early-age cement-based materials.