Engineering Geology World, Vol. XVI, No. 2/2021
Larionova N.A.
Larionova N.A., 2021. Influence of the shale ash composition on the efficiency of clay soil strengthening. Engineering Geology World, Vol. XVI, No. 2, pp. 42–51, https://doi.org/10.25296/1993-5056-2021-16-2-42-51.
The problem of using the ashes of thermal power plants for soils’ strengthening as an independent binding material has received great attention in our country and abroad. It remains quite relevant at the present, since the percentage of their use remains extremely low. Active ash, formed during the combustion of oil shale, is a valuable secondary mineral raw material and is widely used for the production of building materials. The possibility and feasibility of their use and for soils’ strengthening have been established. The use of shale ash provides building materials with desired properties for creating structural layers of road pavements. This significantly reduces the consumption of traditional binders in the form of cement or lime. The article is devoted to assessing the possibility of using shale ash for strengthening moraine loam, studying the effect of the chemical and mineral composition of ash on the hardening process of ash and ash-soil mixtures and changing their physical and mechanical properties over time. It has been established that the hardening process of hardened soil is slow, and its strength depends on the dosage of shale ash and the hardening time. The influence of the peculiarities of the chemical and mineral composition of shale ash on their hydraulic activity and efficiency of use for strengthening clay soil has been revealed. It is noted that the hydraulic activity of ashes is determined by the peculiarities of their composition, including the presence of free CaO, the content of SO3 and clinker minerals, the indices of the basicity modulus and the quality factor, the ratio of CaO/SiO2, CaO/MgO. The difference between the processes of hardening of hydrated ash and ash-ground mixtures over time is emphasized. The use of shale ash as an independent binder ensures not only the production of high-quality building materials but also contributes to the provision of a significant economic effect in the construction of highways, as well as a reduction in the volume of accumulated industrial waste and a decrease its impact on environmental pollution.
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NINA A. LARIONOVA
Lomonosov Moscow State University; Moscow, Russia; nin.larionowa@yandex.ru
Address: Bld. 1, Leninskie Gory, 119991, Moscow, Russia