Microstructural characterization of fresh cement paste via random packing of ellipsoidal cement particles

► The microstructure of fresh cement paste is characterized. ► The effects of cement particle shape on the thicknesses of ITZs and VV are weak. ► The effect of cement particle shape on SV is oblate (κ = 0.66) > prolate (κ = 1.5) > spherical. ► The effect of cement particle shape on the pore size is contrary to the result of SV. ► The statistical results are verified by the experimental and analytical results.