Stabilization of clay with inorganic by-products

New binder alternatives based on industrial by-products were studied for stabilization of clayey soils. The main emphasis was on pulverized, granulated blast-furnace slag activated in different ways, and on binder combinations based on fly ash and waste from desulfuration units. Cement was used as the control binder. The aim of this study was to evaluate the stabilization characteristics of new binder alternatives with different mixture combinations and to understand the effects of geotechnical index properties of clay and chemical/mineralogical composition on stabilization characteristics. The results of the laboratory tests indicate that the strength of stabilized clay is strongly dependent on the water-binder ratio, and that the strengthening effect is minimal at water-binder ratios below a certain threshold value. For the clay types examined in this study, blast-furnace slag activated with cement generally gives higher strengths than cement alone after the relatively long hardening periods usually employed in stabilization. It is possible to predict final strengths by accelerating the hardening with heat treatment. A temperature of 60°C seems to be suitable for this acceleration.