Paper Title
The Dependence of Pristine Graphene-Cement Based Composites on Pristine Graphene Dosages and Sizes: Mechanical and Microstructural-Related Properties

Abstract
The pristine graphene-cement based mortars with four concentrations of pristine graphene (PRG) and two particle sizes are explored in this study. The results show that the 0.07% PRG with 56µm size improves the compressive and tensile strength at 28 days by 34.3% and 26.9%, compared to 23µm size with an improvement of 14.3% and 13%, respectively. The better improvement of the ultra-large PRG size (56µm) in comparison with the smaller PRG size (23µm) is due to the stronger bonding of strengthened PRG-cementitious gels because of higher cement hydration products and friction adhesion forces of the ultra-large size PRG sheets in the cement matrix. The studyalso reveals that PRG could accelerate the hydration process, regulate microstructure, and increase the load-transfer efficiency due to the interlocked PRG-cementitious gels in the space network structure of the cement matrix. Keywords - Pristine graphene; Cement mortar; Mechanical properties; Acceleration; Dispersion; Microstructure.