STUDY OF A CONCRETE FORMULATION APPROACH WITH POZZOLANIC ADDITION BASED ON THE DREUX GORISSE METHOD: THE CASE OF MILLET POD ASH

Environmental issues have led construction researchers to work on reducing the amount of cement used in cement concrete, a material that is harmful to the environment because of its high CO2 emissions. Their approach has been to use concretes in which some of the cement is replaced by pozzolanic materials. In this case, the binder used in pozzolanic concrete is an equivalent binder (cement + pozzolan). The difficulty lies in mastering the behavior of the equivalent binder so that it can be integrated into one of the concrete formulation methods. The aim of this study was to investigate the behavior of the equivalent binder (cement+ millet pod ash) for integration into the DREUX-GORISSE concrete mix design method. To this end, the effect of millet bean ash on the binders strength class was studied, in order to adjust the quantity of water to maintain the desired workability. The absolute density of the millet husk ash is taken into account when determining the absolute volumes of the aggregates. After processing the results, the strength class of the equivalent binder is the product of the strength class of the cement and the pozzolanic activity index of the pozzolan used. The quantity of water required to achieve a given workability is the sum of the quantity of water required for workability in the case of cement alone and the product of the mass of pozzolan by a coefficient equal to 0.66.