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The influence of mechanical and chemical activation on the mechanical properties of high-density concrete and cement mortar has been studied. Portland cement optimum content necessary for apparent increase in the mechanical properties of cement composites has been determined. The size-content study of the mechanically and chemically activated cement has been undertaken. The heat emission development of the mortar based on activated binder has been studied by means of calorimetric measurements. It has been demonstrated that increase in concrete hardening after the activation originates from formation of the cement fine-crystalline structure. According to the elemental analysis data, hydrated calcium silicates (CSH) are developed in spherical globules.

Rakhimova N.R.,Kazan State University of Architecture and Engineering | Rakhimov R.Z.,Kazan State University of Architecture and Engineering
Advances in Cement Research | Year: 2015

Waste concrete powder is a promising mineral admixture to Portland cements and alternative binders such as alkaliactivated slag cements (AASC). The individual constituent of the waste concrete powder is mechanically activated in the ground hardened cement paste (GHCP). This influence on the properties of AASC fresh, hardened pastes and hardened concretes was assessed depending on the concentration (5-60%) and the fineness (200-800 m2/kg) of the GHCP, the nature of the alkali activator (sodium carbonate and sodium silicate) and the curing conditions (normal conditions and steam curing). The considered properties for the fresh paste were the water/binder ratio and the setting time; for the hardened paste, the water absorption, density and compressive strength after 2, 7, 14, 28, 180 and 360 d of ageing were assessed. The GHCP accelerated setting and hardening, improved the early strength and long-term strength of the AASC paste and replaced slag by up to 45%. The influencing factors affected the strength of the AASC with GHCP as an admixture in the following order: alkali activator type > curing conditions > GHCP fineness. The accelerating and strengthening effects of the GHCP were more intense under normal curing conditions than under steam curing, and the GHCP activated more AASC using sodium carbonate than sodium silicate. The.compressive and flexural strength of concrete samples based on AASCs with 7 5-10% GHCP included improved up to.

Rakhimova N.R.,Kazan State University of Architecture and Engineering | Rakhimov R.Z.,Kazan State University of Architecture and Engineering
Cement and Concrete Composites | Year: 2014

The sustainable development of cement manufacturing requires extension of the raw material base, including large-tonnage waste. Hydrated mortar waste is a promising mineral resource for the production of Portland cements and alternative binders, such as alkali-activated slag cement. The influences of ground-hydrated mortar aged for 3 months on the properties of alkali-activated slag fresh and hardened pastes were performed. The results show that the properties are dependent on the concentration (2.5-60%), cement:sand ratio (1:1-3) and fineness (200-600 m2/kg) of the ground hydrated mortar; the alkali activator (sodium carbonate and sodium silicate); and the curing conditions (normal conditions and steam curing). The fresh paste properties that we considered in this study included the water requirement and the setting time; the hardened paste properties we considered were the water absorption, the density, and the compressive strength after 2, 7, 14, 28, 180 and 360 days of ageing. The ground hydrated mortar improved the early strength and the long-term strength of the alkali-activated slag paste and replaced the slag up to 50%. The factors that affecting the strength of the alkali-activated slag cement with ground hydrated mortar as an additive were, in order of influence, alkali activator type > curing conditions > cement:sand ratio > ground-hydrated mortar fineness. © 2014 Elsevier Ltd.

Popov A.O.,Kazan State University of Architecture and Engineering
Magazine of Civil Engineering | Year: 2015

A distinctive feature of the reinforced pile foundation is that there is no direct contact between the foundation (pile cap) and pile, and the load on the reinforced base is transmitted through the soil. This seemingly minor difference from the pile foundation makes a radical change in the stress-strain state, and hence in the carrying capacity and settlement. In this article on the basis of the previous experimental and theoretical research the author presents a new methodological approach to the calculation of the final settlement of clay soil foundations reinforced with vertical elements, allowing for the effect of the limit state areas.

Romanova A.I.,Kazan State University of Architecture and Engineering
Procedia Engineering | Year: 2016

Creating a unified approach to the organization of the control system and the evaluation of the quality of construction at the facilities of the investment and construction of the complex is one of the most pressing problems of today. State power in the creation, implementation, management and control of such management system does not show an increased interest. Thus, the solution of this problem, namely, the introduction of a new quality management system, should the task of a self-regulatory organizations. In this regard, to prepare the article it is necessary to study the existing system of the construction quality control in the Republic of Tatarstan and the established self-regulation system to propose measures of improving the quality of construction products. To achieve this goal, the following tasks were considered: the prerequisites of self-regulation establishing; study of the foreign experience in the development of self-regulation in the construction; review and analysis of the existing quality control system in the Republic of Tatarstan designed to improve the quality of construction products in the investment-construction complex of the Republic of Tatarstan through the process of improving the self-regulation system and insurance arms. © 2016 The Authors.

Fakhertdinova D.I.,Kazan State University of Architecture and Engineering
2013 International Conference on Interactive Collaborative Learning, ICL 2013 | Year: 2013

Technical and information competence's skills are main important skills for technical engineering educated students. Physics - is the main science for these students because of it is the base science for study technical specialties. Using on line physic labs allows build these main important skills. © 2013 IEEE.

Rakhimova N.R.,Kazan State University of Architecture and Engineering
Revista Romana de Materiale/ Romanian Journal of Materials | Year: 2015

The effects of ground used sand (GUS), ground fly ash (GFA) (class F), and microsilica (MS) on water requirement, setting time, and compressive and bending strength development of alkali-activated slag-blended cements (AASBC) were studied. Siliceous blending materials were found to be able to replace up to 50% of ground granulated blast furnace slag (GGBFS) and contributed to up to 90% improvement of strength of AASBCs, The granulation for GUS, granulation, curing conditions, and basicity of GGBFS for GFA, and curing conditions for MS have effects on the development of the properties of the AASBCs. © 2015, Procema SA. All rights reserved.

Kats B.A.,Kazan State University of Architecture and Engineering
Complex Analysis and Operator Theory | Year: 2012

We study boundary properties of the Cauchy transform of certain distributions with supports on non-rectifiable curves and apply these results for solution of the Riemann boundary value problem. © 2010 Springer Basel AG.

Akhmadiev F.G.,Kazan State University of Architecture and Engineering
Theoretical Foundations of Chemical Engineering | Year: 2014

A brief review of general approaches to solving multicriteria optimization problems, their advantages and disadvantages, and computational bottlenecks in the solution of certain problems with numerical implementation was performed. The optimization solutions for three specific types of engineering processes were given with relation to the construction of their mathematical models based on different approaches. The numerical results of solving the optimization problems for the considered examples used in practice for the optimal implementation of corresponding processes were obtained. © 2014, Pleiades Publishing, Ltd.

Stroganov V.F.,Kazan State University of Architecture and Engineering
Polymer Science - Series D | Year: 2015

The influence of the structure of adamantane-containing epoxy polymers (EP) on their resistance to thermal, chemical, and biological aging under conditions of the action of aqueous solutions of the carboxylic acids, which are known as metabolites of the vital activity of mold fungi, is studied. It is established that the adamantane-containing EP show higher heat resistance and thermal stability than do epoxy amine polymers based on aliphatic diamines, providing high adhesive strength up to temperatures ranging from 150 to 200°C. It is shown that incorporation of the adamantane fragments into the structure of a hardening agent increases the resistance of the epoxy polymers to aggressive media (water, alkalis, acids, and solvents), including metabolites of mold fungi. © 2015, Pleiades Publishing, Ltd.

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