Limestone Calcined Clay Cement (LC3) is a low-carbon cement[1][2][3][4] developed by the École Polytechnique Fédérale de Lausanne (EPFL), Technology and Action for Rural Advancement (TARA), Indian Institute of Technology (IIT) Delhi, IIT-Bombay, IIT-Madras, and the Central University of Las Villas (Cuba).
It is the result of an ongoing cooperation between EPFL and partners in India and Cuba on developing low carbon and resource efficient raw materials for cement manufacturing.
[19][20] Testing and standardisation[7] was carried out by the EPFL, IIT-Delhi, IIT-Bombay, IIT-Madras, and the Central University of Las Villas (Cuba).
[10][27] Adding large amounts of calcined clay (metakaolin) and ground limestone to the dry cement powder,[28][29] when adding water to the mix for making concrete, cement and additives start to hydrate and the soluble aluminates released in water from the calcined clay react with the calcium carbonate from the finely crushed limestone.
[30][31] The reactive alumina present in metakaolin reacts with the ground limestone, leading to a less porous structure than in other concretes and providing equal strength as with higher levels of clinker substitution.