Effects of carbonization temperature on the performance of bamboo fiber-reinforced cementitious composites and their potential applications in deicing pavement

This study investigates the effects of carbonization temperature and fiber dosage on the mechanical properties, thermal conductivity, and rapid chloride penetration test (RCPT) response of bamboo fiber-reinforced C40 concrete. Bamboo fibers were incorporated at dosages of 1.5%–4.5% and used in three states: uncarbonized, carbonized at 300 °C, and carbonized at 800 °C. Compressive strength, splitting tensile strength, thermal conductivity, RCPT charge passed before and after dry-wet cycling, and microstructural characteristics were evaluated. Uncarbonized fibers improved tensile resistance but reduced thermal conductivity because of their porous and insulating structure. In contrast, the 800 °C carbonized bamboo-derived material enhanced thermal conductivity and exhibited lower RCPT charge-passed values, accompanied by a carbon-rich structure and a denser fiber–matrix interface. At 3.5% fiber content, the 800 °C carbonized mixture showed a 19% increase in thermal conductivity relative to the reference mixture under the reduced-aggregate testing conditions. Scenario-based finite element analysis showed that lowering the ambient temperature from −3 to −8 °C increased the predicted heating time from 2.6 to 3.4 h. The study identifies a mechanical–thermal trade-off associated with carbonization and examines its implications for a layered pavement concept.