Microstructure-based homogenization method for early-age creep of cement paste

In this study, a microstructure-based homogenization method is proposed for the creep behavior of cement paste at early age. With the aid of hydration model, the evolution of microstructure in hydrating cement paste is represented as a function of time. The inherent creep of C-S-H is characterized by the B3 creep model proposed by Bazant, whereas other chemical phases are assumed to behave elastically. A two-step homogenization method combining the analytical and numerical homogenization is proposed. Analytic homogenization method is applied for the effective mechanic properties of composites in the hydration model. Then the numerical homogenization is conducted based on the obtained microstructures. The numerical homogenization is implemented with the aid of FEM software Comsol Multiphysics. The reliability and precision of homogenization method are validated by experimental data in literature. The creep and creep recovery behavior of cement paste at early age is comprehensively studied. The main novelty of this study is the quantification of the contribution of each mechanisms to the creep and creep recovery behavior of cement paste at early age, which provides insights to better understand the creep mechanisms.