Chemical Bonding, Electronic Properties, Mechanical Strength, and Thermal Conductivity of Cement Compounds by First-Principles Study

We present a comparative study between the structural, electronic, elastic, and thermal conductivity of cement compounds (C3S, C2S, C3A, and C4AF) using first-principles calculations. The calculated structural properties are in good agreement with the experimental data. The electronic properties of cement compounds are mainly contributed from the O 2s and Ca 3d orbitals due to the strong ionic character. Herein, C3S and C2S are insulators, with respective band gap energy of 3.34 and 5.217 eV. Moreover, the cement compounds contribute to the strength increment by investigating the independent elastic constants, Debye temperature, and Grüneisen parameter. In the comparison, the highest thermal conductivity of C4AF compound was up to 2.423 W m⁻¹K⁻¹, which is ~11 times higher than that of C2S (0.218 W m⁻¹K⁻¹).