Kinetics of mixed binder strength gain

Abstract

Introduction. The storage of pond ash at ash dumps has a negative impact on the environmental situation in the nearby settlements, dumps constantly dust and pollute water sources. To solve this problem, it is proposed to use ash from pond ash as a component of mixed binder. Since the specific surface area of pond ash is different throughout the dump, it is necessary to study its influence on the strength set of mixed binder under different curing conditions.Materials and methods. The equipment on which the experiment was carried out is listed. To determine the specific surface ПСХ-12 device was used, ash drying was carried out in a desiccator. The samples were stored in a normal solidification chamber. The chemical composition of pond ash from TPP-5 of Omsk was presented.Results. Experimental data on the strength of samples of mixed binder at the age of 1,3,7,14,21,28,90 days of normal hardening and data on the strength of samples after heat and humidity treatment are presented. Durability of mixed binder composition with specific surface of hydraulic ash of 460-490 m2/kg under normal hardening conditions amounts to 42.57 MPa which corresponds to natural strength. The composition with the use of pond ash 460-490 m2/kg after water removal increased strength by 12% in comparison with the control composition. Compositions with specific surface of wet pond ash 220-250, 340-370, 650-700 m2/kg show durability results lower than the control ashless composition irrespective of hardening conditions.Discussion and conclusions. It is proved that the use of pond ash with a specific surface of 460-490 m2/kg is rational. Its strength under normal conditions of hardening is 42,57 MPa, which corresponds to the strength of the concrete. The composition with the use of wet pond ash 460-490 m2/kg after heat and moisture treatment has an increase in strength by 12% compared to the control composition. Increased strength of mixed binder compositions is associated with acceleration of pozzolanic reaction in them, the products of which have a positive effect on the strength of the products.