Pozzolanic activity assessment of calcined clays with complex minerals content

Abstract

The present work deals with the possibilities for using calcined clays of different compositions and mineral content as pozzolanic admixtures to cement mortars. The optimal burning conditions for each type of selected clay are determined according to the losses on ignition. The contribution of the main clay minerals to formation of the total pozzolanic activity by the burning process is evaluated by way of various physical, chemical (Frattini, Chapelle and the method of active admixtures) and mechanical (strength activity index) methods. The pozzolanic properties of the calcined clays are determined by 30% cement replacement. A calculation procedure for the prediction of the pozzolanic activity of burned clays, depending on their raw mineral content, is proposed.