Microstructure d’un Béton de Poudre Réactive Extrudable

The exceptional performances of reactive powder concrete are well known since the nineties. But their more and more raising price limits their use for marginal applications, when other concrete cannot answer a technical and/or architectural request. The aim of our study is to find an extrudable and sustainable composition in aggressive environment. A mix with crushed quartz in replacement of part of the silica fume shows very interesting properties: extrudability, very good durability and better mechanical strength with an improvement of shrinkage. This paper deals with the systematic study - using RXD and SEM - performed during the development of the best concrete. It highlights the effect of the polycarboxylate on the hydration of the type of cement used in RPC.