Electromechanical control method of rheological and technological characteristics of building mixtures

Abstract

The paper is devoted to the enhancement of control methods for the rheological and technological properties of building mixtures: foam concrete, injection mortar, and tamponage mortars. For this, a new method for determining these properties and a device that extends the range of measurements in comparison with the widespread ones are developed. This device consists of the DC motor that directly brings the spherical spindle into a uniform motion in the building mixture. It allows for transforming the rheological characteristics into electrical signals during the preparation processes of mixtures. For the first time, the physical-mathematical model of such dependence is obtained. Also, for the first time, the experimental and calculated dependencies between the values of the amperage and the common technological characteristics of the cement mortar and conditional viscosity have been determined. It is established that the viscosity is within 0.23 ÷ 0.07 Pа⋅s, and the current strength is within 60 ÷ 225 mА for sand-cement mortars with the ratio 1:1 ÷ 1:1.5 and W/C 0.7 ÷ 1.2. For cement suspension, the viscosity is equal to 2.7 Pа⋅s for W/C = 0.3 and 1.2 Pа⋅s for W/C = 0.5. Wherein, the amperages comprise 607 and 278 mА for W/C = 0.3, 226 and 116 mА for W/C = 0.5 for spindles of different diameters. Obtained dependencies could be the basis of the software for the development and of the automatic monitoring system of rheological and technological characteristics of cement-sand mortars, as well as the automatic management system for preparing building mixtures with set rheological properties.