3D printing and thermal characterisation of expanded graphite-infused concrete structure

Cement is widely used as a material for the building and construction industry. One of the ways to improve concrete properties is to add additives into the formulation of cement. Addition of different additives can have significant impact on the concrete’s thermal properties. With global warming as the top threat in the world, it is critical future use of concrete can effectively and efficiently insulate heat so as to reduce energy consumption to cool the room down. In this report, I will be focusing on improving the thermal properties of 3D printed concrete and while maintaining a level of buildability and printability for the 3D printers. This report is uses a 3D printable and buildable concrete formulation as the control group. This formulation was selected because it is trial and tested from previous studies where the concrete is of industrial standards. Expanded graphite, the additive chosen for this study, is then added to this formulation at 5 different weight percentages and a rheology test is conducted to compare the results with the control group’s results. 3 wt% had the closest results to the control group hence it was chosen to be used for 3D printing for further thermal testing. Next, referring to previous FYP report on effective thermal conductivity testing based on steady-state absolute technique, this report will compare the thermal conductivity of the control group and 3wt% expanded graphite to see if the addition of additives will improve the thermal conductivity. Using a heater to heat the concrete and a cold plate to assist the concrete to reach steady state quicker, we can see on average a 15% improvement in overall thermal conductivity for the concrete with expanded graphite added. Other notable observation includes time taken to reach steady state, temperature at steady-state and time taken to cool down. In all scenarios, the concrete with expanded graphite added fare better in terms of being used as a building material with better timings. Hence, it is concluded that the addition of additive such as expanded graphite for 3D printed concrete can result in significant improvement in thermal conductivity.Bachelor of Engineering (Mechanical Engineering