OPTIMIZATION OF THE SHORT-TERM RESISTANCE OF CONCRETES MADE FROM 20M-TYPE CEMENT

This study shows that it is possible to make a concrete with high earl y strength when using a type 20M cement having a low heat of hydration , as used by Hydro-Quebec in hydroelectric structures. Such a concrete allows the forms to be removed rapidly while developing a minimum hea t of hydration. This property is due to a low water/binder ratio and i s obtained by specific dosage of additives such as a superplasticizer, a silica fume, and a fine limestone filler. Substitution of 20% of th e cement by silica fume and limestone filler did not alter the develop ment of the compressive strength compared to a normal strength concret e presently in use. A factorial design has allowed to optimize, after a limited number of trials, the mix design for resistance in young con crete made with type 20M cement.