Valery Bratchun, Vitaly Bespalov, Oleg Pshenichnykh, Valentin Demeschkin,
Nikita Leonov
Technological Hot and Cast Road Asphalt Mixes
Donbas National Academy of Civil Engineering and Architecture
Abstract. Based on the methodology of the system analysis of the proposed physical and chemical models of modified asphalt binders and asphalt concretes using an experimental and statistical description, new science-based technological solutions have been developed and implemented for obtaining complex-modified hot and cast asphalt-polymer-sulfur concrete mixtures for the installation and maintenance of non-rigid pavement pavements of highways increased durability, capable of withstanding rutting, fatigue failure, crack resistance and thermal oxidation, as a result of the complex modification of petroleum road bitumen with butadiene methylstyrene rubber SKMS-30 together with technical sulfur and the formation of a spatial polymer network in the organic binder. Hot asphalt polymer concrete with complex modified microstructures of optimal compositions is characterized by the following quality indicators: compressive strength, MPa at 0 °С R0 = 8…10, at 20 °С R20 = 5,0…6,5, at 75 °С R75 = 1,2…1,4; swelling, % of volume – 0; water saturation, % of the volume 1,5…2,0. Cast asphalt polymer-sulfur concretes are characterized by increased shear resistance at high positive operating temperatures (conditional Marshall stiffness at 60 °C 23,1 kN), long-term water resistance coefficient (90 days), Kvd = 0,89, frost resistance coefficient after 100 cycles of alternating freezing thawing F = 0,85, coefficient of thermal aging after 2 000 hours of heating in the climatic chamber IP-1 at a temperature of 75 °C and ultraviolet irradiation, Kst = 1,27. Technologies for the production, laying and compaction of hot asphalt-polymer-sulphur-concrete mixtures have been developed.
Keywords: complex-modified butadienemethylstyrene rubber SKMS-30 and technical sulfur hot and cast asphalt-polymer-sulphur-concrete mixtures, optimal temperatures for the production, laying and compaction of hot asphalt-polymer-sulphur-concrete mixtures.
Anna Lischenko
Investigation of Alkaline Heat-Resistant Binders Based on Zuevskaya TPP Slag
Donbas National Academy of Civil Engineering and Architecture
Abstract. In this paper, the thermomechanical properties are studied, the compositions of slag-alkali binders based on ground coal slag of the Zuevskaya TPP are optimized in order to use them for heavy alkaline heat-resistant concretes. The influence of the silicate modulus, as well as the influence of the density of low-modulus liquid glass (Ms = 2,0) on the activity of slag-alkali binders, was revealed. The change in the physical and mechanical properties of the stone of slag-alkali binders at ordinary temperature, after drying and firing at a temperature of 1 000 °С was studied. It has been established that slag-alkaline binders based on ground coal slag from the Zuevskaya TPP have increased heat-resistant properties. Thus, the possibility and expediency of using ground coal slag in the manufacture of alkaline heat-resistant concretes has been proved. Also, alternative slag-alkali binders make it possible to increase the raw material base for the preparation of heat-resistant concretes and reduce the environmental damage caused by the production of cement.
Keywords: slag-alkali binder, heat-resistant concrete, linear shrinkage, strength, slag TPP, weight loss.
Maxim Vodolad, Elena Yegorova, Sergey Lakhtarina, Irina Petrik,
Anastasia Chenchenko
Optimization of the Composition of Segregation-Resistant Self-Compaling Concrete Mixtures and their Based Concrete
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article considers the influence of the mineral additive of the Zuevskaya TPP ash and slag mixture, the viscosity modifier SCC-10 and the superplasticizer Sika ViscoCrete 5-600 N PL on the slump, fluidity of self-compacting concrete mixtures and the strength of concrete at an early and design age. Optimization of the composition of concrete mixes was performed using a full three-factor experiment. The areas of optimal compositions of concrete mixtures were determined by the content of mineral and chemical additives, which ensure the production of concrete mixtures with a slump index for the cone flow diameter of 588 mm (class SF1), as well as concrete with a compressive strength at the design age of 38 MPa. The studied compositions of self-compacting concrete mixes are recommended to be used for non-reinforced or low-reinforced concrete structures – floor slabs, pipelines, tunnel linings, foundations, which are subject to high requirements for surface quality and do not require additional processing.
Keywords: self-compacting concrete, industrial wastes of Donbass, viscosity modifier, superplasticizer, optimization of concrete composition.
Alexey Belous a, Mira Overchenko b, Dmitry Vybornov b
Heat Gains From Students in the Buildings of Educational Organizations
a LLC «North-West Project Management and Innovative Solutions», b Donbas National Academy of Civil Engineering and Architecture
Abstract. One of the main tasks of engineers in the construction industry is to create and maintain the microclimate of the premises with minimal financial and energy costs. At the same time, it is necessary, based on the conditions of comfort for a person, to take into account not only the thermal characteristics of modern building materials and structures, but also indicators of thermal comfort. Special attention should be paid to heat gains in the buildings of educational institutions due to the lack of unambiguous data on this issue in the regulatory literature. The article discusses some methods for determining heat gains from people, performs a comparative analysis of the methods, establishes factors that affect the metabolism and thermal state of a person at rest and when performing work of various categories of complexity, and also calculates the values of heat gains from students, taking into account age and physiological characteristics, which can be used in the future when performing calculations of the heat balance of buildings of educational institutions. A comparison of the considered methods for determining household heat inputs from students in educational institutions with the data of a field study was made, which showed a high degree of convergence of the study results.
Keywords: metabolism, human heat balance, heat exchange, household heat inputs, premises of educational institutions.