Etude de la formation du monocarboaluminate de calcium hydrate au contact d'un granulat calcaire dans une pate de ciment portland

Abstract Calcite reacts with Portland cement paste. Calcium hydrocarboaluminate C 3 A.CaCO 3 .11H 2 O is formed by reaction between hydrated calcium aluminate C 3 A.1/2CO 2 .12H 2 O and carbonate ions produced by dissolution of calcium carbonate. Investigations by X ray diffraction and S. E. M. show that, due to the low mobility of dissolved ions, these reactions are limited to the interfacial zone, and the reaction rate depends on W/C. The effective contact surface between paste and aggregate is growing because of these reactions and the mechanical properties of the bond are improved.