This work intends to predict the effects of hydration on the deterioration of heterogeneous cement-based materials (CBM). The objective is to simulate the thermo-chemo-mechanical behavior of a structural entity (macrobody) utilizing the representative volume element (RVE) characterization of a heterogeneous cement-based material (CBM) microbody. In this context, the thermal, chemical, and mechanical properties are defined at the microscale (RVE level), as are the constitutive and evolution laws for each material. The method proposed by [1] is used to model the micro and macrobodies of the CBM structure. In this method, coined as Direct FE2, the passage of the macro-to-micro and micro-to-macro quantities is replaced by multipoint constraint equations (MPCs) relating the degrees of freedom (DOF) of the RVE with those DOF of the macrobody element, resulting in a one-level solution strategy; that is, non-nested solution strategies are required. It is proposed that the damage model evolves only in the cement material, rendering it a meso/micromechanical description of the damage. However, the presence of inhomogeneities at this level influences the damage initiation and evolution. The proposed damage model follows the classical ideas of the Mazars [2] damage models. However, we implement improvements to the classical theory to enable this model to monitor the changes in the cement's microstructure throughout the hydration process. The whole model is programmed inside the software ABAQUS using Python scripts and FORTRAN user subroutines. We analyze some selected numerical examples that illustrate the evolution of damage in structures under adiabatic and semi-adiabatic conditions. The promising numerical results aid the understanding of possible cracking/damage regions caused by hydration effects in massive structures at early age.