Research Projects

India ranks second globally in Construction and Demolition (C&D) waste generation, but its recycling capacity is only 2.5%. The country is currently facing a shortage of pristine aggregates due to infrastructure development and mining restrictions. Despite the potential for extracting high-value materials from C&D waste, reclaimed concrete (RCA) is restricted to low-end applications, such as rigid pavements. The presence of hydrated cement mortar paste (HCMP) around aggregates has been found to be the root cause of inferior quality of RCA and concrete systems containing RCA. Other dominating parameters controlling the quality and concentration of HCMP include bonding between aggregate and mortar, which depends on the mineralogy and morphological characteristics of aggregates and parent mortar composition. The comminution mechanism adopted for recycling and crushing energy chosen for breaking waste concrete may also impact the quality of different fractions of RCA (coarse, fine, and concrete fines) and the performance of paving concrete. The proposed project aims to comprehensively understand these parameters and link them with the behavior of rigid pavements containing RCA. It will study intermolecular and interfacial bond strength, the influence of different mineralogies/lithologies of aggregates and cement-mortar compositions, and the potential of concrete fines as supplementary cementitious admixture or replacement for cementitious binder systems. The findings could be useful in establishing a framework for extracting high-quality RCA for various high-end applications.