English English

Strokova V.V.

Doctor of Engineering Sciences (Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov, Russia

EFFICIENCY OF STABILIZERS OF VARIOUS COMPOSITION FOR STRENGTHENING THE SOIL WITH A MINERAL BINDER

https://doi.org/10.34031/2618-7183-2020-3-1-30-38
, , , ,
 30-38 p.
Abstract
The depletion of natural deposits of traditional inert mineral raw materials (sand, gravel) used to create effective layers of the foundations of roads leads to the development and application of new technologies and alternative materials. One way to solve this problem is to use local raw materials. For the construction of the lower layer of the road basement local soils are often used. However, their use is associated with the development of a set of measures to increase their efficiency, such as stabilization (by the use of chemical additives) and/or strengthening (by the introduction of various types of binders). In this regard, the paper analyzes the physicomechanical characteristics of reinforced clay soils obtained by introduction of various types of stabilizing additives in the presence of an inorganic mineral binder of hydration hardening type - cement - taking into account the recommendations for the used additives. The object of research was the most common representative of clay soils of the Belgorod region – heavy dusty clay loam. As a result of the studies, the authors established the reasonability of the use of the additives in the presence of cement, the most effective compositions of the reinforced soil were identified, contributing to the improvement of its controlled physical and mechanical characteristics. In addition, the need for additional studies to adjust the recommended composition of reinforced soil was established.
PDF

COMPARATIVE EVALUATION OF ROAD PAVEMENT STRUCTURES USING CEMENT CONCRETE

https://doi.org/10.34031/2618-7183-2019-2-4-56-63
, , , ,
 56-63 p.
Abstract
The results of studies on the use of modified basalt fiber reinforced cement concrete coating in the design of hard pavement are presented. It is shown that the use of fiber cement concrete in road structures allows to reduce the thickness of the coating, while having a margin of safety in the concrete layer, and the frame of micro-reinforcing components allows to reduce penetrating loads.
PDF

CHEMICAL REACTIVITY ASSESSMENT METHOD OF NANOSTRUCTURED LOW CALCIUM ALUMINOSILICATES

https://doi.org/10.34031/2618-7183-2019-2-3-5-11
, , ,
 5-11 p.
Abstract
Nowadays, the production of high-performance composites is a relevant objective in construction industry. Normally, geological and/or technological conditions of phase formation are responsible for chemical and structural characteristics of raw materials. In this regard, the use of a certain material dictates terms to opti-mizing production process, efficient use and, therefore, requires to develop a method for quality evaluation of raw materials. This approach allows a considerable time saving and raw materials sources, while the evaluation of final performance characteristics of designed materials is being done. The biggest interest in this area is focused on new types of developed and poorly-studied composite systems which results in a lack of capacity to design materials with known performance and, therefore, constrains the areas of application of construction composites
Among such composite systems there are zero cement alkali-aluminosilicate systems or geopolymers. For geopolymers production a wide range of different aluminosilicates with varied characteristics potentially can be used. And also, in each certain case, the quality evaluation methods for aluminosilicates should be different.
This study is focused on chemical reactivity assessment method of crystalline (mainly, nanocrystalline) low calcium aluminosilicates exposed to high-alkali media. The solubility degree in high-alkali media and compressive strength performance were evaluated in this study in order to define chemical reactivity of low calcium aluminosilicates. The compressive strength data demonstrated a positive correlation with the crystallinity degree of aluminosilicates.
PDF

STRUCTURE FORMATION IN ALKALI ACTIVATED ALUMINOSILICATE BINDING SYSTEMS USING NATURAL RAW MATERIALS WITH DIFFERENT CRYSTALLINITY DEGREE

https://doi.org/10.34031/2618-7183-2018-1-4-38-43
, , ,
 38-43 p.
Abstract
The efficiency of traditional raw materials using as well as expanding of potential uses for non-conventional and alternative raw materials with different origin is the tasks exiting interest among material scientists and manufacture stuff. Investigation of the above is oriented on solution of such scientific problem as more deep understanding of structure and features of material. The results obtained also allow solution of some technological, technical and economical tasks.
Greatly, it is actual when using of new types of raw materials as well as when synthesis of new composites. Concerning the construction material science field, the classic problem is the looking for ways to study the reactivity of raw components under different conditions, its control and, generally, its increasing to produce higher performance materials.
Among the popular and widely-used construction materials are alkali-activated binders and relevant composites.
In this study the results of granulometric analysis of suspension based on alkali-activated aluminosilicate with different crystallinity degree are presented. It was found, when treatment of aluminosilicate grain by alkali activator leads to the grain solubilizing (but differently depending on crystallinity degree of aluminosilicate) and formation of alkali-aluminosilicate gel that reacts with unreacted part of the grain according to structure affinity principle. It was also determined the crystallinity degree of aluminosilicate component is inversely proportional to its solubility in highly-alkali environment. The model of structure formation for geopolymer system under alkali effect is offered.
PDF

INFLUENCE OF THE GENETIC FEATURES OF SOILS ON THE PROPERTIES OF SOIL-CONCRETES ON THEIR BASIS

https://doi.org/10.34031/2618-7183-2018-1-1-69-77
, ,
 69-77 p.
Abstract
In order to form strong soil-concrete structures in parallel with the introduction of binder, an additive with a multicomponent composition that is activating the structure-forming process should be applied. Such addi-tive is usually called stabilizer of soil, its introduction allows achieving a positive effect for soils with a high proportion of finely dispersed fraction in its composition.
The article considers the main aspects of use in road construction of complex soil reinforcement by introducing a stabilizer and binding component. This technology will solve the problems of deficiency of high-quality traditional raw materials, lead to better physical and mechanical properties, increase labor productivity and reduce production costs.
As a result of the carried out studies, principles for improving the quality characteristics of reinforced soil were developed, taking into account the mineral composition of clay raw materials. As the main hypothesis of the study an increase in the hydrophobicity of stabilized soil by blocking the hydrophilic centers of clay rocks should be marked. This circumstance helps to reduce the consumption of cement in the reinforced soil without reducing the operational and physical-mechanical characteristics.
The dependence of the degree of effectiveness of the introduced stabilizing additive on the structural and chemical characteristics of clay rocks has been established, which decreases from montmorillonite and X-ray amorphous phases to kaolinite. Mixed layered formations, illite and chlorite act as intermediate minerals. Aluminosilicates act as the filler in this system that do not come into contact with the molecules of the stabilizer. To assess the degree of efficiency of interaction of the components of a soil-concrete mixture as an integral indicator it is necessary to use the cationic capacity of the soil.
PDF