Using high-temperature-modified graphene to alleviate pore pressure in concrete under high temperatures

In high-temperature environments, rapid pore pressure buildup in cement-based concrete can cause explosive spalling, making its reduction crucial for mitigation. This study utilise high-temperature-modified graphene (MGP) powder to regulate the pore structure of cement-based materials, thereby reducing pore pressure. The effects of replacing cement with MGP at varying dosages (0, 5, 10, and 15 wt.%) on pore pressure and concrete performance were investigated, along with water absorption, hydration product, temperature gradient, and mechanical properties. While the compressive strength decreased slightly with graphene at room temperature (6.9%, 16% and 50.9% reductions at 5, 10 and 15 wt.%, respectively), the residual strength loss after 400 °C was significantly lower: 46.3%, 17.8%, and 29.0% for 5, 10, and 15 wt.% MGP, respectively, compared to 72.9% in the control group. A 10 wt.% MGP dosage with 20 μm was found to be optimal to reduce the pressure of concrete. Overall, this work provided a new application of MGP to improve the heat resistance of cement-based materials.