Industrial Manufacture of a Low-Clinker Blended Cement Using Low-Grade Calcined Clays and Limestone as SCM: The Cuban Experience

The results of an industrial trial for the production and applications of a low-clinker blended cement-also called low carbon cement (LCC)-based on the system clinker-calcined clay-limestone are presented. A low-purity kaolinitic clay was calcined in a rotatory kiln and used in the manufacture of the ternary blended cement. The produced cement contains 50 % of clinker, 41 % of the combined addition calcined clay-limestone in a 2:1 proportion and gypsum. The ternary blend accomplish with the requirements of Cuban standards for blended cements although it exceed the allowed additions limit in 10 %. Concrete prefabricated elements made with the LCC under industrial conditions exhibit nice mechanical and permeability properties. It is estimated that the massive production of this type of cements may contribute to the reduction of CO2 emission in more than 25 % related to daily practice.