Fundamental physical properties of graphene reinforced concrete

The increasing global population and the alerting global climate change demand novel and disruptive advancements of the construction industry. Manufacturing of concrete and cement, the most widely used construction materials, accounts for more than 10% of global carbon emissions and this number continues to grow each year. The research questions that this PhD project is addressing is the development of a novel method of nano-engineering traditional concrete with atomically thin materials such as graphene. The objectives of the project are: 1) to investigate if graphene introduces any changes to the chemical reactions, responsible for the fundamental mechanical properties of concrete; 2) to characterise any changes in the strength, durability, water impermeability and heat transfer of the structural material upon adding graphene to it. The novel engineering approach taken to answer these questions is by adding graphene to the concrete composition by substituting water via uniform dispersion in liquid. To this end, first a novel method of liquid exfoliation of graphene is developed and the resulting water suspensions fully characterised using Raman spectroscopy. Then, concrete samples are prepared according to British standards for construction and tested for various properties such as compressive and flexural strength, cyclic loading, water impermeability and heat transport. A separate in-depth study is carried out to understand the formation and propagation of micro-structural cracks between the concrete's internal matrix planes, and graphene's impact on total fracture capacity and resistance of concrete. Lastly, multiple experiments are performed to investigate the microcrystallinity of cement hydration products using X-ray diffraction.