75504 2712-8172 7 59 2015 1-79

RAR RUS 4-17 Siberian State Automobile And Highway Academy Aleksandrov Anatoliy Aleksandrov00@mail.ru

Omsk, Russia

Siberian State Automobile And Highway Academy Kalinin Alexsandr a1exsandr55ne@mail.ru

Omsk, Russia

Improvement of shear strength design of a road structure. Part 1. Deformations in the Mohr – Coulomb plasticity condition The article presents the Mohr – Coulomb plasticity condition modified by incorporating a third parameter depending on sample axial deformation value for which sliding planes are formed and developed under triaxial compression. A relative characteristic of a sample’s work under shear strength is offered; it is determined by the ratio of the axial strain 1 to the ultimate strain 1с for which the parameters of the Mohr – Coulomb failure envelope are defined. Based on the triaxial test data it was established that for 1/1с 10.5862/MCE.59.1 strength сriterion plasticity condition deformation triaxial testing of soils https://engstroy.spbstu.ru/article/2015.59.1/ 01.pdf

RAR RUS 18-29 International Humanitarian University Azarova Irina partisia@mail.ru The main aspects of the value-oriented management of investment and construction housing projects The urgency of the problem of providing people in CIS countries with quality, affordable housing with minimal risk of implementation of housing projects is obvious. To solve this problem, the authors proposed to review the principles of managing investment and construction housing projects based on project management tools, stakeholder theory and evolutionary theory of values. It is necessary to shift the focus from maximizing profits of construction companies to increasing the satisfaction with the significant social housing projects for all of their stakeholders. The aim of this study is to develop an effective and easy-to-use mechanism for evaluating, balancing and managing the social and public values of property along with its monetary value. The value of residential projects is expressed in non-financial indicators in order to get away from the idea of profit maximization. The value of the project is regarded as the coincidence between results of the project and the interests of its stakeholders, and stakeholder interests are represented as the desired economic, social, psychological, resource and other expected benefit of the project. The proposed system of value-based management of housing projects covers the period of the investment project from the idea of a residential building to its end of exploitation. We discuss which groups of agents should manage value-oriented housing projects and the means by which it should be implemented. A technique of analyzing project stakeholders based on expert evaluations is proposed, and a mathematical model for assessing the value of projects in non-financial terms is developed. The results achieved using current theoretical and methodological principles correspond to the goals of scientific research and can be used in value-oriented management of residential projects as well as in other sectors of project management in research and educational processes. 10.5862/MCE.59.2 value-oriented management project management in construction residential construction stakeholder approach https://engstroy.spbstu.ru/article/2015.59.2/ 02.pdf

RAR RUS 30-38 Kazan State University of Architecture and Engineering Morozov Nikolai nikola_535@mail.ru Kazan State University of Architecture and Engineering Krasinikova Natalia knm0104@mail.ru

Kazan, Russia

Kazan State University of Architecture and Engineering Borovskikh Igor borigor83@gmail.com Factors affecting the deterioration of concrete pavement slabs The behavior of constructions under actual operating conditions is affected by exposure to the environment. It is important that concrete roads and airport pavings are resistant not only to mechanical damage, but also to the effects of alternate freezing and thawing. The causes of early failure in concrete have been shown using prefabricated road slabs as an example. The causes of loss of performance properties of the roadway have been established, which are primarily dependent on the quality of raw materials in the concrete. It was found that, aside from durability, uniformity and porosity are important factors in determining the frost resistance of concrete roadways. It was shown that high aluminate content in the cement leads to concrete destruction in the first year of structure use. The results may also indirectly indicate a violation of forming technology during slab production. 10.5862/MCE.59.3 road slabs strength frost resistance water absorption high alumina cement https://engstroy.spbstu.ru/article/2015.59.3/ 03.pdf

RAR RUS 39-49 7004630127 Ufa State Petroleum Technological University Babkov Vadim babkov.ugntu@gmail.com

1, Kosmonavtov St., Ufa, Russia, 450062

Ufa State Petroleum Technological University Yumagulov Rufat yumagulovra@gmail.com Georekon JSC Kildibaev Rinat rbstroi@mail.ru Stress and strain state of road slabs during production and use in the Western Siberia conditions Precast concrete road slabs are used for auto-road construction in the severe hydrogeologic and climatic conditions of Western Siberia. The advantages of precast concrete road pavements have been proved by more than half a century of use, which is confirmed by the current steady demand for this type of product. The problem of developing the precast concrete road system in the Western Siberian and the Far North regions is therefore still a critical task. The long experience of manufacturing and using prestressed concrete road slabs showed that they are at risk of crack formation not only when the road pavement is used but also at the manufacturing stage. To explore the reason of crack formation, stress and strain state analysis of road slabs was performed using the ANSYS 14.0 software. It was revealed that the existing prestressed reinforcement layout of the functional standard series enables the development of transverse tensile stress σty in slab ends and adjoining parts. The occurring tensile stress can initiate longitudinal cracks in operation by multiple repeated exposure typical for the road slab usage conditions. Based on the results of the analysis, a technical solution optimizing road slab reinforcement was suggested to reduce the detrimental effect of tensile stress in slab ends from the prestressing force. The optimization involves increasing the distribution dispersability of tensile reinforcement at cross-sections by the prestressing force without sacrificing its prestress capacity, resulting in reducing tensile transverse stress to acceptable levels. 10.5862/MCE.59.4 road slabs rigid road revetment road construction https://engstroy.spbstu.ru/article/2015.59.4/ 04.pdf

RAR RUS 50-56 Peter the Great Saint Petersburg Polytechnic University Volkova Anna volkova-anna-andreevna@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Paykov Alexey paykov-alexey@yandex.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Stolyarov Oleg oleg.stolyarov@rambler.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Semenov Sergey ssgrus@gmail.com

Polytechnicheskay, 29

6701751705 0000-0002-7889-1996 Peter the Great Saint Petersburg Polytechnic University Boris Melnikov kafedra@ksm.spbstu.ru

Polytechnicheskay, 29

Structure and properties of textile reinforced concrete In this paper the structure and properties of textile-reinforced concrete were investigated. Two types of high strength reinforcing fabrics made of glass and carbon rovings were used in this study. The samples of textile-reinforced concrete were produced. The mechanical properties of the developed samples were determined via a three-point bending test. The maximum flexural strength and reinforcement efficiency were calculated. It was found that the samples with textile reinforcement have higher strength characteristics as compared to nonreinforced concrete. Furthermore, the deformation behavior of reinforced concrete was analyzed. The advantage is in higher residual load-bearing capacity, which allows maintaining the integrity of the structure. 10.5862/MCE.59.5 textile-reinforced concrete warpknitted fabrics mechanical properties structure https://engstroy.spbstu.ru/article/2015.59.5/ 05.pdf

RAR RUS 57-65 Voronezh State University of Architecture and Civil Engineering Glazkov Sergey glackov@mail.ru Stabilizing parquet blocks with epoxy resin While parquet blocks and panels from stabilized wood show much promise as finishing materials, their widespread use is limited by their low dimensional stability in variable-humidity environments. Existing solutions to stabilize the blocks have several disadvantages, including hard-to-find or toxic stabilizers. This is why this study discusses modifications of epoxy resin which has sufficient functionality for effective structuring. We analyzed the capillary-porous structure of different types of wood, and established the patterns associated with a reduction in the porosity or the specific volume of voids in pine, birch and oak. The basic characteristics of impregnating compositions indicating the high penetrative and structuring capabilities of epoxy resin have been discovered. It is shown that in addition to increasing the strength characteristics, there is a steady decline in water absorption and swelling with an increase in resin content in the wood. It has been found by the method of test fluids that curing the epoxy resin in the presence of hexamethylenediamine is accompanied by a decrease in the proportion of polar components in the total value of the surface tension. Oligomer molecules were shown to penentrate pine wood cells, providing a high moisture protection effect. The results suggest it is possible to use epoxy resin to modify parquet blocks and panels that would be used under variable humidity and high impact loads. 10.5862/MCE.59.6 wood materials acid-base theory oligomer modification epoxy resin https://engstroy.spbstu.ru/article/2015.59.6/ 06.pdf

RAR RUS 66-73 Kazan State University of Architecture and Engineering Gaifullin Albert 447044@list.ru Kazan State University of Architecture and Engineering Rakhimov Ravil caf.str.mat@yandex.ru Kazan State University of Architecture and Engineering Rakhimova Nailia rahimova.07@list.ru The influence of clay additives in Portland cement on the compressive strength of the cement stone The introduction of mineral additives to binders, especially to Portland cement, is one of the promising trends for solving the resource and energy saving problems, as well as problems of environmental protection during production and application. Expanding the supplementary cementitious materials resource base can be achieved through the use of natural pozzolans and thermally activated polymineral clays(commonly known as glinites in Russia). One type of glinite is metakaolin, which is obtained by calcination of kaolin clays. Metakaolin is widely and effectively used as a pozzolanic additive due to its beneficial effect on the physical and mechanical properties of Portland cement-based materials. The obstacle to its wide production and use are the limited deposits of pure kaolin clays in many countries, including the Russian Federation. In this respect, the studies of pozzolanic activity of the most common mineral clays and their use in some countries have significantly advanced. Similar studies were widely performed in the 1940s in USSR. It seems reasonable to renew this trend to provide a scientific base for the production of local pozzolans made of clays commonly used in different regions. Comparative studies of the effect of 5 clays differing in mineral and chemical composition, calcination temperature and specific surface area, and high-quality metakaolin, on the strength of hardened Portland cement paste have been performed. It has been established that introducing 5…10 % of composite clays calcined at 400…8000 C° and milled to a specific surface area of 290…800 m2 /kg into Portland cement enhanced the strength of the hardened cement paste considerably better than the introduction of metakaolin with a specific surface area of 1200 m2 /kg. The findings of the study suggest that many kinds of commonly used polymineral clays have a specific calcination temperature and dispersity, which results in a higher pozzolanic activity compared with metakaolin. 10.5862/MCE.59.7 glinite clay calcination mineral composition calcination temperature Portland cement concrete additive cement stone compressive strength https://engstroy.spbstu.ru/article/2015.59.7/ 07.pdf

RAR RUS 74-79 0000-0003-0413-3946 Federal University of Technology Minna Auta Samuel Mahuta smahuta@yahoo.com

Minna, Nigeria

St. Petersburg State University of Architecture and Civil Engineering Shiwua Aondowase John jshiwua@yandex.ru Federal University of Technology Minna Tsado Theophilus Yisa teoaggie@yahoo.com Compressive strength of concrete with millet husk ash (MHA) as a partial replacement for cement A study of compressive strength of concrete with millet husk ash (MHA) as partial replacement for ordinary Portland cement (OPC) is presented. The strength characteristics was investigated by casting and testing 54 specimen cubes sizing 100 mm x 100 mm x 100 mm for varied percentage replacements of cement (0 %, 10 % and 20 %) with water cement ratio of 0.65. These cubes were cured for 7 days, 14 days, 28 days and 35 days to target strength design of 25 N/mm2 at 35 days crushing. The result shows that at 35 days the compressive strength for 0 %, 10 % and 20 % replacements are 32.00 N/mm2 , 25.56 N/mm2 , and 23.18 N/mm2 , respectively. It is clear that MHA as a pozzolanic material can be incorporated into cement in amounts of no more than 10 % replacement in order to develop a good and hardened concrete. 10.5862/MCE.59.8 compressive strength concrete aggregates millet husk ash replacement for Portland cement https://engstroy.spbstu.ru/article/2015.59.8/ 08.pdf