Development of recycled aggregate concrete with pristine graphene

Author: Olayinka Abioye

  • Thesis download: available for open access on 24 May 2024.

Abioye, Olayinka, 2022 Development of recycled aggregate concrete with pristine graphene, Flinders University, College of Science and Engineering

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Abstract

This thesis research aimed at the development of recycled aggregate concrete with pristine Graphene. This work was undertaken in response to the detrimental effect construction and Demolition waste has on the landfills and the continuous depletion of natural coarse aggregate. The process of converting the construction and demolition waste into recycled coarse aggregate was seen as the best option to tackle the highlighted problems associated with construction and demolition waste. From research, pristine graphene was seen as the best nanomaterials that could be used to reinforce this recycled coarse aggregate that possesses lower mechanical properties than the natural coarse aggregate. The pristine graphene at different dosages i.e., 0.1%, 0.2%, 0.3% and 0.5% was introduced into recycled coarse aggregate and soaked for up to 24 hours for the pore spaces of the recycled coarse aggregate to be filled up with the solution of pristine graphene. A mix of 6 batches of concrete specimen consisting untreated recycled aggregate concrete, treated recycled aggregate concrete and the conventional concrete were made. Mechanical and durability properties of concrete such as compressive strength, splitting tensile strength, drying shrinkage and water absorption tests was performed on these mixes. It was found that the addition of graphene helped in the increase in both compressive and tensile strengths of reinforced RAC. Mix N50R50P0.2% consisting 0.2% of pristine graphene was the optimum dosage and produced 60.74MPa which is 19% more than the untreated RAC mix. The effect of graphene was also seen in the water absorption and drying shrinkage of hardened concrete. The drying shrinkage of mix N50R50P0.3% containing 0.3% of graphene dose had the least shrinkage of 160 micro strain which 66% lower than the untreated RAC and 82% lower than the control mix. The water absorption on the other hand was reduced to 2.69% in mix N50R50P0.1% having 0.1% of pristine graphene. It was concluded that the use of recycled aggregate concrete should be encouraged in the construction industry in order to reduce landfill intake, environmental problems and the depletion of natural resources.

Keywords: Recycled Coarse Aggregate, Recycled Aggregate Concrete, Natural Aggregate, Construction and Demolition

Subject: Engineering thesis

Thesis type: Masters
Completed: 2022
School: College of Science and Engineering
Supervisor: Dr Aliakbar Gholampour