Mixing and Casting HP and VHP Concrete in the Laboratory
During a symposium on high performances concrete, two half-days devoted to the making of high performance (HP) and very HP (VHP) concrete were organized by the E. N. S. de Cachan. This chapter summarizes the objectives and results of these practical experiments. One of the preoccupations is to see how it is possible to make an HP concrete with local materials, in order to ensure that the increase of cost of these designed HP concretes stays reasonable, and their use becomes feasible. The concretes have a very high workability and their strengths are near the predictions. Only the gravels of the Paris area (silico calcareous) have had some problems. Two types of concretes were considered: HP concrete with local materials found in the Paris area; and VHP concrete with materials designed by our Canadian colleagues. Dry mixing is necessary to reduce agglomerates and split up the "microscopic particles" inside the materials.