Bulletin of Prydniprovs'ka State Academy of Civil Engeneering and Architecture

10-19

Authors: Derevyanko V. N., Dr. Sc. (Tech.), Prof.; Shapovalova O. V., Tech. Sc. Cand., Doc.; Kondratieva N. V., Tech. Sc. Cand., Doc.; Maksimenko А. А., Tech. Sc. Can., senior researcher.

Problem statement. There is a question of optimum choice of type, length and quantitative content of fibers for achievement of high strength of compositions made on the basis of cement of various activities, construction sand and reinforcing components as a part of dry building mixes. Analysis of publications. The role of fibers is that they take a part of load, interfere with development of cracks and displacement of blocks, according to numerous researches which results are generalized in works of Desov A. E., Akhverdov I. N., Solomatov V. P., Vyrovoy V. N., etc. According to existing theories, destruction of composition is carried out due to breaking and stretching of fibers. There are different types of models and theories of destruction of materials on the basis of mineral binders. According to re-searchers, material is not isotropic environment, and deformation and destruction of concrete is caused by the influence of external forces. In case of introduction of discrete fibers, the mechanism of tension can be presented to the following. One part of fibers works for stretching and the other one interferes with shift of particles, increasing connectivity of the system. Mineral and metal fibers, located parallel to the operating external load, increase rigidity of the system. As organic fibers have low module of elasticity, they most likely interfere with shift of the particles and reduce arising secondary tension. Therefore, the effect of reinforcing depends on structure, matrix strength and also on parameters of fibers and their properties. The purpose of the article. Development of a method of determination of the minimum length and content of components in cement and fibrous composition. Conclusions. Thus, the made analysis of the research results shows that the most effective length of polypropylene fibers with a diameter up to 15–17 µm in compositions of cement and sand mortars is in limits of 5–7 mm. The fibers content in mortars, at which compression strength increases by 15–30 %, and bending strength — by 40–70 %, does not exceed 0,2 % of the binder mass. It is typical that reinforcing is more effective for compositions in which a low-branded binder is applied. It testifies that it is possible with disperse reinforcing to eliminate partially decreasing of cement binder activity that is a result of its storage. So, strength gain due to reinforcing of mortars with binder activity 20 MPa is 50–60 % whereas strength of mortars, in which Portland cement with activity of 49 MPa is applied increased, only for 25–30 %.

28-35

Authors: Yakovyshyna T. F., Ph.D., Ass. Prof.

Raising of problem. The modern industry needs initiate amplification of the technogenes is intensity that affects the processes of the micro- and ultramicroelements migration and lead to accumulation significant quantities of the elements of the first class of toxicity on the Earth surface, which primarily include heavy metals Ecological peculiarities of the technophiles elements, as long half-life in the environment (for Cd – 155 years, Zn – 500 years Pb –up to several thousand years); biophylly reflected through toxicity to living organisms; ability to induce carcinogenic and mutagenic effects; concentration in food chains, cause extreme danger to humans and biota. Low utilization of the heavy metals from the raw promotes their dispersion in the biosphere and the formation of technogenic geochemical anomalies. Purpose. Conduct an ecological assessment of the heavy metals (Cd, Pb, Zn, Mn and Cu) technogenes is by examining biogeochemical parameters on the global planetary level, both those relating directly to the properties of metals, and those related to human activities and including of these toxic elements in the industrial products and waste. Conclusion. Technogenesis of the heavy metals has increased significantly during the twentieth century. According to the positive nature of the tehnophyllya symmetry relative to the average, intensity of the Pb and Cd inclusion with the man-made stream the biogeochemical cycles occurred more gradually than Zn, Cu and Mn. Destruction activity of the chemical elements changed in some Pb > Cu > Zn > Cd > Mn in the early twentieth century, Cd > Cu > Pb > Zn > Mn — in the twentieth, showed establishing of the toxic, carcinogenic and mutagenic properties of the lead, so mankind has realized the risk of the biosphere and it is subsequent biogenic migration in the food webs. For load of the techno-genic module has been installed increasing the intensity distribution of heavy metals in the noosphere and has been proved by comparison of the chemical elements in the waste production and product after its life with clarkin the litho-sphere possibility of recuperation and recycling, so use these valuable components in future production.

44-49

Authors: Konoplianik A. Yu., Cand. of Sc. (Tech.), Ass. Prof.; Iliev I. M., Сand. of Sc., Ass. Prof.; Chernavskikh V. V., Postrgrad. Stud.

Formulation of the problem. Currently due to modernization of the residential building the priority is given to the problems of selection of light effective materials that can be simultaneously applied to the bearing and heat-insulating structures. The advantage of effective materials can be fully implemented in the construction of individual houses, where along with various building designs, thermal devices such as stoves, fireplaces, saunas, chimneys, etc. are used. Analysis of the current state of development and research of lightweight concrete has shown that the most appro-priate as a binder would be the usage of liquid glass. Positive experience of usage in metallurgy the compositions of heat refractory concrete on liquid glass [1] has shown that they have a number of distinctive positive properties that have clear advantages compared to conventional concrete on cement and lime binders., namely: to have accelerated setting time. Analysis of publications. Since the essential characteristic for liquid glass mixtures is the hardening pro-cess, which is based on the reaction between the liquid glass and a hardener, it is necessary to use an effective hardener, which provides hardening conditions for these mixtures. Previously as a hardening agent sodium silicofluoride was of-ten used [2], at that the optimal amount of sodium silicofluoride was established, which is 10–12 % from liquid glass weight. In the study [3] the possibility of replacement of silicofluoride with self scattering slag of metallurgical enter-prises was shown; the later contain β and γ — 2CaO∙SiO2. The most accessible of these slags is ferrochromium slag, which is a waste of ferrochrome production. There is a positive experience of usage in the compositions of heat refrac-tory concretes aluminous cement, which is a hardener for liquid glass [4]. Experimental data established that the most appropriate hardener for liquid glass is ferrochromium slag [5]. In this case, based on liquid glass with hardener of fer-rochrome slag, a number of concrete with high physical-mechanical, thermal and insulating properties was obtained. Currently usage as a hardener of sodium silicofluoride, ferrochrome slag and alumina cement is constrained due to their high cost and the severance of economic ties with Russia, the producing country of these materials. The aim of the work was to determine the reaction of possibilities with respect to the liquid glass of Portland cement, phase composition of which is also presented with calcium silicates. At the same time there was a task to compare the dates of the beginning and the end of the hardening of the mixtures with known hardeners of liquid glass with mixtures with hardeners from Portland cement of different brands. Conclusions. The performed testing of liquid glass mixtures with different hardeners showed that the most economically viable is the usage of Portland cement M400 as a hardener for liquid glass. In the conditions of the building in the summer time it is feasible to expect reduction of setting time for mixtures with increased air temperature.

57-65

Authors: Vorobyov V. V., Cand. of Arch., Doc.; Koneva K. A., Stud.

Problem Statement. Publications dedicated to the ecovillages consider questions that are called ecological. But in fact such questions as the use of sustainable building materials, reducing the energy needs of buildings and others don’t represent ecological ones. Theoretical principles of ecological environment proposed by researchers for general plans of settlements also don’t show the interaction with the natural network of connections. Meanwhile ecology is first of all the science of the relationships in ecosystems. It means that if ecological settlements don’t consider these relationships, they cannot be regarded as ecological. And vice versa: the morphological structure of the general plan of ecological settlement should be considered as a tool for inscribing man and his habitat in a network of natural connections. Analysis of recent publications. Numerous types of natural connections can be divided into groups based on different criteria. In general there are three of them: physical, energy and information connections. The guarantee of human prosperity is to inscribe in the continuous round of nature - the cycle of matter, energy and information and support it wisely. Space and its shape, created in an urban environment and beyond, are not perceived properly by human. Any geometric shape, no matter what space it creates, is originally transcendental. Modern architects design spaces of transcendence without realizing it. Transcendental approach allows us to consider the shape from the standpoint of the unity of internal and external, material and the ideal, visible and invisible. This is a fundamentally different view of the world and its spatial (including architectural and urban) forms. There is only one significant force that unites all the ecosystems — the information. Information flows are connected with the shape of the space. Ecological architecture and ecological settlements are the objects and spaces that restore human to the natural system of connections. Purpose. The aim of the publication is to reveal the aspects of the general plan of ecological settlement as of an important element in the matrix of the network of connections in ecosystems. Conclusion. To stop the destruction of the matrix of natural connections because of human activity in the field of architecture and urban design, we have to turn to the structural and planning organization based on the spatial inscribing into the matrix of ecosystem connections without their deformation.