2.англ.
Ph.D. thesis: 187 p., 15 tables, 52 figures, 2 appendixes, 170 references.
Modification of building products of concrete using technology and equipment for impulse impregnation.
The topicality of the topic is due to the need to improve the physical and mechanical characteristics of concrete construction products, in particular, reducing water absorption, which contributes to increasing frost resistance, as well as increasing strength indicators, since traditional methods of their processing do not provide sufficient resistance to aggressive operating conditions, moisture and frost.
The purpose of the work is to modify construction products made of concrete to improve physical and mechanical properties by means of impulse impregnation of their capillary-porous structure.
The object of research is construction products made of concrete, technologies and equipment of impregnation to obtain improved physical, mechanical and operational properties of products.
The subject of research is the study of physical and mechanical characteristics of construction products made of concrete using technology and equipment for pulsed impregnation.
In the first chapter, a study of the structure of concrete construction materials was conducted and the main destructive factors that worsen the operational characteristics of concrete products were determined. An analytical review of known methods of modification of building materials of capillary-porous structure was performed, in particular, a review of impregnation technologies of building materials made of concrete. The existing equipment for the implementation of methods of impregnation of building materials was analyzed.
The second chapter gives the main characteristics of the materials that were used for conducting experimental research. A schematic diagram of the developed laboratory stand for concrete impregnation with a list of equipment and control and measuring devices is presented. The method of experimental research is described. A description of methods and equipment for testing experimental samples in accordance with standard methods has been made. Quadratic regression equations were obtained that describe the dependence of the values of the depth of penetration of the impregnation composition on the parameters of the proposed equipment and the dynamic viscosity of the impregnation composition.
In the third section, the influence of various impregnation compositions on the formation of physical and mechanical characteristics of construction products made of concrete is determined. Mathematical modeling of the processes of penetration of impregnation compositions into the capillary-porous structure of concrete, which occur during pulsed impregnation, is carried out. Mathematical modeling of the assessment of the technical condition of the equipment was performed.
In the fourth chapter, an experimental study of the process of impulse impregnation of construction products made of concrete is carried out. The water absorption of the samples that were impregnated with a hydrophobizing solution based on silicone by the proposed pulse method decreased by 56.7% compared to the samples processed by the vacuum-pressure-vacuum method. The compressive strength of concrete impregnated with liquid sodium glass by the impulse method increased by 18.2%, and the flexural strength increased by 34% relative to samples processed by the vacuum-pressure-vacuum method.
In the fifth chapter, a new effective technology is proposed, which involves the modification of construction products made of concrete by pulse impregnation, and the technological scheme of the modification process is presented. On the basis of an analytical review of existing impregnation equipment designs, new designs of equipment prototypes for impulse impregnation of building materials and products, which implements the proposed modification technology, were developed and proposed.
