Perspectives on blended cementitious systems with calcined clay-limestone combination for sustainable low carbon cement transition

This paper presents a summary of the major findings from the studies conducted at Indian Institute of Technology (IIT), Madras on Limestone Calcined Clay Cement (LC3), in comparison with plain portland cement and fly ash-based binder. The study attempts to delineate the chemical and physical effects of binder components in LC3 on hydration and hardening, property development, binder chemistry and durability indicators to evolve fundamental understanding on the performance of such low clinker binders. Such an assessment can drive the practical adoption and extend the applicability of such binders in various domains of cement-based materials. The experimental strategy involved the assessment of the pore structure evolution and electrical properties on cementitious pastes, along with measurement of the durability parameters on concrete for resistance to ingress of moisture by absorption, and chloride ions by migration and diffusion mechanisms. The synergistic interactions of the blend of calcined clay and limestone impact the physical structure positively at early ages as opposed to fly ash systems, which require prolonged curing to realise their potential. The study reveals a combination of calcined clay and limestone can be a potential combination for producing high-performance concrete, more specifically in a chloride laden environment, along with the beneficial alternative resource utilisation and sustainability prospects. © 2020, Associated Cement Companies Ltd.. All rights reserved.