Thermally Assisted Liberation of Concrete and Aggregate Recycling: Comparison between Microwave and Conventional Heating

Microwave-assisted concrete liberation and aggregate recycling is highlighted by many research groups due to its efficient and effective recycling process. In this paper, a series of experiments are conducted to study the heating results of concrete under microwave and conventional heating processes. The temperature variations of concrete under two different heating approaches are obtained. The crack characteristic and material damage during the different heating processes are illustrated. Particularly, the energy efficiency was investigated for two approaches. Results proved that concretes were broken more effectively under microwave irradiation than in conventional furnaces, and the aggregates can be easily separated under the sufficient power input. Scanning electron microscope (SEM) analysis proved that after microwave treatment, intergranular fractures are formed at mortar-aggregate interfaces, few cracks occurred after conventional heating processes. The research proves that, compared with conventional heating, microwave irradiation could liberate concrete and recycle aggregate effectively, with less heating duration and lower energy input required.

Automated summary

The study found that concrete can be more effectively broken down and aggregates can be more easily recycled under microwave irradiation. Compared to conventional heating, microwave heating requires less time and energy input.