Influence of Graphene Oxide on the Self-Healing of Cement Paste Fractures in Ccus Cementing: A Combined Analysis of Experiments and Molecular Dynamics Simulations

Abstract

Abstract: Cracking of the cement paste used for CCUS cementing can jeopardise the integrity of the wellbore, jeopardising the security of CO 2 storage. After carbonisation and self-healing for 28 days, the experimental results indicate that the compressive strength growth rate of cement combined with 0.10wt.% GO reached 1077%, whereas the control group only reached 850%. More CaCO 3 crystals developed on the crack surface of GO cement as the carbonisation self-healing time increased than in the control group. The self-healing volume of GO cement cracks was 74.3%, which was higher than the control group (34.5%). The results of a molecular simulation indicate that GO can enhance the capacity of cement-based materials to absorb CO 2 and speed up the diffusion of CO 2 . GO supplies nucleation sites for CaCO 3 crystals and accelerates the carbonisation self-healing process of cracks.

Keywords: CCUS, Crack, GO, Carbonised self-healing, molecular dynamics simulation