Synergistic effects of ultrafine particles and graphene oxide on hydration mechanism and mechanical property of dune sand-incorporated cementitious composites

摘要

An effective method is proposed in this study to overcome the mechanical defects of dune sand-incorpor ated cementitious composites (DSCC). First, focused on the dispersion behavior of grapheneoxide (GO) in simulated cement slurry, a GO-stabilized dispersion was prepared using noncovalent modification methods. Then, a series of tests were conducted to evaluate the effects of GO dispersion on the mechanical properties and hydration characteristics of DSCC. The results show that the DSCC specimen with full dune sand and GO content of 0.03 wt% achieved 125.41% of compressive strength and 94.9% of flexural strength of the standard sand specimen at a curing time of 28 days. In addition, the porosity and microcracks can be controlled by incorporating GO in the cement matrix. Moreover, a synergistic effect was observed between GO and ultrafine particles in dune sand, which promotes the hydration reaction and pozzolanic effect in cement matrix. (C) 2020 Elsevier Ltd. All rights reserved.