Thermo-mechanical treatment as an upcycling strategy for mixed recycled aggregate

Abstract

The study investigates thermo-mechanical treatment for mixed recycled aggregates (MRA). Six treated aggregates were prepared by heating MRA between 300 °C and 800 °C, followed by 100 abrasion cycles. The thermo-mechanical treatment causes loss in the adhered mortar and improves aggregate crushing, impact and abrasion value up to 700 °C. Concrete prepared with MRA treated at 700 °C, as compared to natural aggregates, shows higher workability (166.67%) and comparable mechanical strength, i.e., compressive (93.72%), flexural (99.94%) and split tensile (97.87%). The sustainability assessment shows that treating MRA with renewable energy can have lower economic costs (89.36%) and carbon emissions (58.05%) than manufacturing natural aggregates.