ИССЛЕДОВАНИЕ ВОЗМОЖНОСТИ ПОВЫШЕНИЯ КАЧЕСТВА ПОДГОТОВКИ СУХИХ СТРОИТЕЛЬНЫХ СМЕСЕЙ В ГОРИЗОНТАЛЬНОМ ЛОПАСТНОМ СМЕСИТЕЛЕ

Abstract

Paddle mixers with horizontal shafts are common at building materials enterprises for the preparation of concretes, mortars, dry mortars. A new design of a horizontal paddle mixer with rod elements located in front of the working surfaces of the blades, changing the trajectories of material particles, increasing their mobility, which leads to an increase in the degree of homogeneity of the mixed material, is considered. The aim of the study was to assess the influence of rod elements on the quality of preparation of a cement-sand mixture, to establish patterns of influence on it by the design and technological parameters of a two-shaft paddle mixer and to determine the areas of their rational values. The following tasks have been solved. A bench installation of a two-shaft horizontal paddle mixer with rod elements has been developed, on which experimental studies have been carried out on the preparation of dry cement-sand mixtures. For the criterion characterizing the quality of the mixture, the ultimate compressive strength of the prism specimens made from it is adopted. Regression equations are obtained that adequately describe the compressive strength of prism samples from the design and technological parameters of the mixer: the angle of the blades, the distance from the working surfaces of the blades to the rod elements, the rotational speed of the blade shafts, and their analysis is performed. The analysis of the change in the ultimate compressive strength of the prism specimens from the parameters under study is carried out, the rational ranges of their values are determined. It was found that a mixer with rod elements allows to obtain a dry cement-sand mixture, products from which have a higher compressive strength. During the work, the method of mathematical planning of experiments was used. As a result of the study, an assessment of the influence of rod elements on the quality of preparation of a cement-sand mixture was carried out, the regularities of the influence on it of the design and technological parameters of a two-shaft paddle mixer and the area of their rational values were established.