Innovative GQDs and supra-GQDs assemblies for developing high strength and conductive cement composites

Abstract

Recently, there has been significant interest in using several types of graphene derivatives to enhance the performance of cement composites. There are novel graphene quantum materials called graphene quantum dots (GQDs) in ultrafine scales, and none has been explored in cement materials. This work presents the effects of these two synthesized graphene derivatives (Qds and BC) on the flow, bulk density, permeable void, water absorption, compressive strength, flexural strength, sulphate attack, electrical conductivity, thermal conductivity, and microstructures of cement composites, compared with commercial graphene oxide (GO) and plain mix. The findings show that the composites containing GQDs have excellent fresh, physical, mechanical, and sulphate attack properties. The 1.2% BC composites has the highest compressive and flexural strengths, with 40% and 108% higher than the control, respectively. Moreover, their electrical and thermal conductivity properties increased as a function of GQDs content. The microstructural bridging mechanism regarding the seeding and crystal growth of C-S-H phase were seen. This study offers novel insights into the role of using GQDs in cement composites such that the materials can be used as a high performance, high conductive concrete, which can be a future of the GQDs in the construction industry.