Investigations on Linz-Donawitz steel slag coarse aggregates as replacement for natural coarse aggregates: emphasis on concrete pavement applications

Long-term performance of concrete pavement is significantly influenced by aggregate characteristics, demanding superior quality. However, the depletion of natural coarse aggregates (NCA) poses a major challenge. This study investigates the use of Linz-Donawitz slag coarse aggregate (LDCA) as a partial or full replacement for NCA in pavement concrete. Mixtures with 0%, 50%, 75%, and 100% LDCA were evaluated for mechanical and thermal properties as replacement for NCA. Results showed improved mechanical characteristics with increasing LDCA content. Thermal properties such as the coefficient of thermal expansion, specific heat capacity, and thermal conductivity increased with LDCA content, while a lower thermal gradient was observed than that of NCA concrete. Finite element modelling indicated LDCA concrete depicted lower stress ratio indicating improved fatigue resistance. Design analysis further showed potential reductions in dowel bar requirements lowering construction costs. These findings highlight LDCA as a sustainable and cost-effective alternative to NCA in pavement applications.