Table of contents
N.I. KARPENKO, Doctor of Technical Sciences, Academician of RAACS, V.N. YARMAKOVSKY, Candidate of Technical Sciences, Honorary Member of RAACS, the Research Institute of Building Physics of RAACS (Moscow)
Main Ways of Resource-Energy Saving at Construction and Operation of Buildings. Part 1. Resource-Energy Saving at the Stage of Producing of Building Materials, Wall Products and Enclosing Structures.
Main ways of resource-energy saving at the stages of production and use of basic components of concrete in construction (composite low-clinker binders and fillers manufactured on the basis of using products of anthropogenic waste processing) are scientifically substantiated and formulated. An analytical review is done; main ways of development of the industry of extreme lightweight concretes for producing wall products and enclosing structures oriented to resource-energy saving are defined.
Keywords: resource-energy saving, building materials, composite low-clinker binders, porous and dense fillers, extreme lightweight concretes.
V.A. EZERSKY, Doctor of Technical Sciences, the Białystok Technical University, the Republic of Poland; P.V. MONASTYREV, Doctor of Technical Sciences, R.Yu. KLYCHNIKOV, Candidate of Technical Sciences, the Tambov State Technical University.
Optimization of Thermal Modernization of a Large-Panel Residential Building with Due Regard for Service Life of Heat-Proofing Measures
It is shown that the improvement of heat-proofing of a building with the use of expensive and long-lived materials leads to the net saving of means exceeding investments by two times at pay-back time of 20.8 year.
Keywords: heat-proofing of buildings, thermal modernization, economical evaluation, net discounted saving of means, service life.
S.S. KAPRIELOV, Doctor of Technical Sciences, the Research, Design and Technological Institute for Concrete and Reinforced Concrete named after A.A. Gvozdev; I.A. CHILIN, engineer (email@example.com), OOO “Enterprise Master Beton” (Moscow)
Ultra-High-Strength Self-Compacting Fibrous Concrete for Monolithic Structures
Results of the study of properties of ultra-high-strength self-compacting fibrous concrete of classes above B100 are presented. The technology of manufacturing this material is based on the combination of ultra-high-strength matrix the bulk of which represents the analogue of the Reactive Powder Concrete - powder concrete - and steel fibre. Trends of changing the strength in the course of axial compression and tension at bending depending on the amount of fibre in the concrete mix are shown. Ultra-high-strength self-compacting steel-fibrous concrete of B100 - B130 classes notable for advanced remoldability and manufacturability with strength limits at axial tension above 10 MPa, at tension in the course of bending above 20 MPa, an initial modulus of elasticity of 44-50 hPa and a dynamic modulus of elasticity of 46-55 hPa has been obtained.
Keywords: steel-fibre concrete, ultra-high-strength concrete, dynamic loads, monolithic structures.
I.M. BARANOV, Candidate of Technical Sciences, OOO “NTTs EMIT” (Moscow)
Problematic Issues of Technology of Manufacturing Special Concretes of High Quality
To create a system of evaluation and classification of properties of molding mixes for extra-strong and self-compacting concretes, concretes for underwater concreting and repair compositions with further standardization for ensuring high quality and physical and mechanical properties of concrete from these mixtures a device and technique of definition of their rheological properties are proposed.
Keywords: self-compacting concretes, static viscosimeter, rheological properties.
T.A. KRASNOVA, Head of Scientific-Technical Service, N.I. BOROULYA, Head of Testing Laboratory, OOO “Torgovy dom SUPERPLAST” (Vladimir)
Chemical Modification of Concretes for In Situ Concrete Works
Main modifiers of concretes and building mixes which are anion-active surfactants – polymethylenenaphthalenesulphonates (Plasticizer C-3), lingosulphonates (LST), polycarboxylate ethers (PK) as well as some carboxylic acids and their derivatives are considered. An action mechanism of these modifiers is described; an assessment of efficiency of monoproducts and complex modifiers on their basis for different cements according to GOST 30459-2008 is made. The advantage of complex area-specific modifiers over monoproducts and universal modifiers is shown.
Keywords: modifier of concrete, action mechanism, complex additive, anion-active surfactants.
A.A. VISHNEVSKY, Candidate of Technical Sciences, Chairman of Scientific and Technical Council, G.I. GRINFELD, Executive Director, N.O. KULIKOVA, engineer, the National Association of Autoclaved Aerated Concrete Manufacturers (St. Petersburg)
Analysis of Autoclaved Aerated Concrete Market of Russia
An analysis of data on manufacturing the autoclaved aerated concrete (AAC) in Russia is presented. The characteristic of established facilities for production of AAC is given; the data on manufacture of AAC in 2012 are reported; the raw materials base for production and characteristics of products manufactured are analyzed. Prospects of the development of autoclaved aerated concrete manufacture in Russia are also considered.
Keywords: autoclaved aerated concrete, analysis of manufacture, small-size products, production capacity.
M.V. KAFTAEVA, Candidate of Technical Sciences, I.Sh. RAKHIMBAEV, Candidate of Technical Sciences, the Belgorod State Technological University named after V.G. Shukhov
About Effect of Primary and Secondary Ettringites on Quality of Autoclaved Aerated Concrete
It is shown that the secondary ettringite is not dangerous to autoclaved cellular concretes as it is generated in the mix under the conditions of low concentration of Ca(OH)2 through the “liquid phase”. A the same time under the temperature of autoclaved treatment of 185-190°C, this is especially noticeable in the case of molding technology of production of gas concrete products, when up to 10% of plaster are introduced in the adobe mix, the last turns into an α-soluble anhydride notable for its higher speed of hydration and significant expansion in the course of hardening. This process is able to cause the generation of defects of the structure of end products at the hardening stage.
Keywords: aerated concrete, primary and secondary ettringites, sulfate corrosion of concrete, autoclaved treatment, crystallization of minerals.
I.Ya. GNIP, S. VAYTKUS, S. VEYALIS, Candidate of Technical Sciences, the Vilnius Gediminas Technical University (Lithuania)
Prognostic Assessment of Creep Deformation of Polystyrene Foam Plastic (EPS) Under Constant Compression
Results of the study of creep of polystyrene foam plastic under the constant compressing load are presented. On the basis of long-time experiments its creep compliance under the constant compressing load is defined. The dependence of creep compliance on the strength of cellular polystyrene under compression σ10% is revealed. The change of creep compliance over time is presented by the coefficient mi. A practical method of prognostic assessment of creep deformation of polystyrene foam plastic on the basis of a short experiment (or with the use of empiric equations for creep complianceIc) and the coefficient mi which takes into account the change of Ic value over time is proposed.
Keywords: cellular polystyrene, long-time compression, creep deformation, forecasting.
A.G. PEREKHOZHENTSEV, Doctor of Technical Sciences, the Volgograd State University of Architecture and Civil Engineering
Simulation of Temperature-Humidity Processes in Porous Building Materials. Part 8. Calculation of the Amount of Unfrozen Water in Porous Materials at Negative Temperature
Methods of calculation of the amount of unfrozen water in pores of materials at negative temperature are considered.
Keywords: porous bodies, unfrozen water.
V.S. LESOVIK, Corresponding Member of RAACS, Doctor of Technical Sciences, A.V. SAVIN, engineer, N.I. ALFIMOVA, A.V. GINZBURG, Candidates of Technical Sciences, the Belgorod State Technological University named after V.G. Shukhov
Assessment of Protective Properties of Concrete with Composite Binders in Relation to Steel Reinforcement
Protective properties of concrete with composite binders (CB) with the use of anthropogenic, natural sands and a super-plasticizer in relation to steel reinforcement are studied by methods of electrochemical investigation, diffusion penetrability, corrosion tests. It is established that in the concrete with CB without super-plasticizer containing up to 50% of sand, the protection of steel reinforcement against corrosion is ensured if consumption of a clinker component is not less than 190 kg/m³. The introduction of the super-plasticizer in CB makes it possible to obtain the concrete of over B40 class with reduced permeability and to reduce the consumption of clinker component up to 110 kg/m³.
Keywords: quartzite-sandstone, composite binder, clinker, anode polarization curve, diffusion permeability.
A.O. ADAMTSEVICH, engineer (MnSpecter@gmail.com), A.P. PUSTOVGAR, Candidate of Technical Sciences, A.V. EREMIN, Master, S.A. PASHKEVICH, Candidate of Technical Sciences, the Moscow State University of Civil Engineering
Study of Influence of Calcium Formiate on Process of Cement Hydration with Due Regard for Phase Composition and Temperature Regime of Hardening
Now chemical additives are actively used in construction for intensification of hardening of concretes and other systems on the basis of a cement binder. Calcium formiate is one of the most popular chloride-free additive-accelerant. Results of the experimental study of influence of calcium formiate on the process of hydration of Portland cements with different phase compositions are presented in the article. The study was conducted with the use of the method of isothermal calorimetry in a wide temperature range of hardening.
Keywords: acceleration of stiffening and hardening, calcium formate, hydration, Portland cement, phase composition.
G.R. BUTKEVICH, Candidate of Technical Sciences, VNIPIIstromsyrye (Moscow)
Problems of Involvement of Mining Industry Waste in Economical Activity
An issue of accumulation and use of mining industry waste is considered. Data on volumes of waste accumulated in disposal areas and slurry storages and volumes of current waste are presented. Proposals which make it possible to awake the industry’s interest in involvement of secondary raw materials in economical activity are formulated.
Keywords: anthropogenic waste, secondary mineral resources, disposal area, slurry storage, non-metallic building materials, Mining Code.
A.G. SHAPAR, Doctor of Technical Sciences, Corresponding Member of the National Academy of Sciences of Ukraine(NASU), Director, the Institute of Nature Management and Ecology Problems of NASU; A.Yu. VILKUL, Chairman of Dnepropetrovsk Oblast State Administration, Supervisor of works of treatment of anthropogenic deposits of Kryvbas (Kryvorizkyi Iron Ore Basin); L.V. YAKUBENKO, N.A. EMETS, Candidate of Technical Sciences, the Institute of Nature Management and Ecology Problems of NASU(Dnepropetrovsk)
Some Aspects of Manufacturing Building Materials in Process of Developing Anthropogenic Deposits of Kryvbas
For efficient development of anthropogenic deposits with the purpose to obtain mineral raw materials for manufacturing building materials, flow charts of treatment of these massifs have been developed. The selection of a flow chart is made on the basis of peculiarities of conditions of these anthropogenic massifs.