Stabilisation of Clay Mixtures and Soils by Alkali Activation

Alkali activation of clay minerals in soil can be used to form a stabilising phase, such as a geopolymer. Because this requires low-temperature curing, typically <100 °C, it has the potential to be a lower-energy method than fired brick or even cement or lime stabilisation. Whilst this has been demonstrated for individual clay minerals and soils, it is unknown how effective this stabilisation method is for naturally occurring soils from around the world. The potential for stabilisation by alkali activation of a given clay mixture or soil could be approximately, but not fully, predicted from its clay mineralogical composition

Feasibility of aluminosilicate compounds from various raw materials: Chemical reactivity and mechanical properties

International audienceThe study of the feasibility of geopolymer formulations was realized from several aluminosilicate sources. Six of them led to the formation of geopolymer-type materials and were confronted with three other reference metakaolins. Several fundamental parameters were identified. A correlation was revealed between these parameters and the reactivity of the mixture, the microstructure and the behavior according to the time of consolidated materials from the various data issues from structural and mechanical characterizations. It has proved possible to predict the behavior of the reactive mixture until its evolution after consolidation for any raw material containing a metakaolinitic phase. All the results allowed to establish a model based on the existence of various geopolymer-type networks: (i) the first one in whom the aluminum atoms participate with the silicon as formers of the network (aluminum-rich) and (ii) the second where the aluminum atoms play the role of compensators in a network rich in silicon

Geopolymer synthetized using reactive or unreactive aluminosilicate. understanding of reactive mixture

International audienc

How to control the geopolymer setting time with the alkaline silicate solution

International audienc