Role des caracteristiques physico-mecaniques des granulats sur la resistance en compression de betons a tres haute resistance

The construction of very high buildings in concrete instead of steel is now quite common and it requires very high strength concretes (100 MPa and over). This new field of utilization of concrete requires a deeper evaluation of the physico-mechanical properties of concrete. The report presents an experimental study about the production of 100 MPa concretes with different kinds of aggregates quarried in Saint Laurent Lowlands in Québec (Canada) and identified as devonian sedimentary rocks and cretaceous basic intrusive rocks. It appears that the higher strengths are obtained when aggregates and cement paste have similar mechanical properties and if coarse and fine aggregates are produced with the same type of rock, preferably a microgranular limestone; there is no noticeable advantage to utilize aggregates with a strength much more higher than that one of the cement paste.