One of the main directions in construction material science is the development of  next generation concrete that is ultra-dense, high-strength, ultra-porous, high heat efficient, extra corrosion-resistant. Selection of such direction is caused by extreme operational impacts on the concrete, namely: continuously increasing load on the concrete and various dynamics of such loads; the necessity in operation of concrete products in a wide temperature range and their exposure to various chemical and physical effects.

The next generation concrete represents high-tech concrete mixtures with additives that takes on and retain the required properties when hardening and being used under any operational conditions. A differential characteristic of the next generation concrete is its complexity that presumes usage of various mineral dispersed components, two- and three fractional fine and coarse aggregates, complex chemical additives, combinations of polymer and iron reinforcement.

Design strength and performance properties level of the next generation concrete is achieved by high-quality selection of the composition, proper selection of manufacturing techniques, concrete curing, bringing the quality of concrete items to the required level of technical condition during the operational phase. However, directed formation of its structure is necessary in order to obtain high-tech concrete.

Along with the traditional methods for regulation of the next generation concrete structure, modification of concrete while using silica nanoparticles is also considered as a perspective one because the concrete patterning occurs due to introduction of a binder in a mineral matrix. Due to this it is possible to obtain nano-modified materials with completely new properties.

The main problem with the creation of nano-modified concrete is a uniform distribution of nano-materials in the volume of the cement matrix which is particularly important in the cases of adding a modifier in micro-quantities. An additional environment is required in order to solve this problem and the environment will form a continuous phase in the composite. This function can be performed by liquid or dispersed phase.

Usage of chemical additives while executing concrete works at negative temperatures is considered as a convenient and economical method. Range of the used antifreeze additives is rather wide. A great number of new additives are advertised but their characteristics have not been practically studied. Evaluation of the antifreeze additive efficiency is unfortunately rather long process and it does not provide comprehensive data on concrete structure formation processes. Due to this development of rapid and comprehensive methodology for construction companies is urgently required.

Freezing processes of antifreeze additive aqueous solutions and hardening of cement paste with them have been investigated in the paper. The paper proposes a methodology for determination of freezing point for aqueous solutions of chemical additives of various applications. Identity of  freezing point for a chemical additive aqueous solution and cement paste with an equal concentration of the additive in the paste pore fluid has been determined while taking  calcium nitrate and sodium formate additives as an example. The paper demonstrates the possibility to evaluate efficiency of antifreeze additive action on the basis of kinetics in temperature changes of the cement paste with additives by its consecutive freezing and defrosting.  A methodology for operational evaluation in the field of chemical additive application for concreting items at negative temperatures has been offered in the paper.  The methodology does not require  deficient and expensive test-equipment. It can be applied at ordinary construction companies and it is comprehensible for personnel of low-qualification.  The paper shows the possibility to develop an original methodology for designing concrete structure which is based on operating efficiency determinations  for single and integrated antifreeze additives.

Quality problem of chemical additives comes down in general to their objective and independent evaluation. As an identification is not made during product delivery for testing and while carrying out the testing there is difference in the results of investigations and finally construction products suffer from their poor quality. In this connection, it is proposed to make some alterations to revised version of the STB 1112 and GOST 30459, so that while supplying chemical additives for certification testing a certificate on additive quality should contain a standard of IR-spectra with active components. Simultaneously, the standard should be applied for additive testing results in accordance with rate efficiency criteria  for GOST 30459. Such norms are accepted for similar European standards.

The paper presents a standard method for identification of organic additives according to IR-spectra, characteristic absorption bands for the Lignopan-type  additives and naphthalene formaldehyde super-plasticizer C-3. However, due to the fact that it is not possible to judge number of functional groups in the product by  absorption band size but it is possible only to assess their availability so it is recommended to use other methods. As an additional characteristics it is proposed to determine magnitude of the dipole moment in a  plasticizer-additive molecule. The authors previously developed a technique and  determined dipole moments in super-plasticizer-additives as in the form of powder so in the form of aqueous solutions, correlation relationship of water reduction additive capability with the magnitude of dipole moment. It has been proposed to manufacturers of plasticizing additives for concrete along with IR-spectra in the technical documentation to indicate a magnitude of the molecule dipole moment  as a generalized characteristics that determines its plasticizing properties.

Composition of a dry mix has been developed for production of non-autoclaved foam concrete with natural curing. The mix has been created on the basis of Portland cement, UFAPORE foaming agent, mineral additives (RSAM sulfoaluminate additive, MK-85 micro-silica and basalt fiber), plasticizing and accelerating “Citrate-T” additive and   redispersible Vinnapas-8034 H powder. It has been established that foam concrete with  density of 400–800 kg/m³, durability of 1,1–3,4 MPa, low water absorption (40–50 %), without shrinkable cracks has been formed while adding water of Water/Solid = 0.4–0.6 in the dry mix,  subsequent mechanical swelling and curing of foam mass.

Introduction of the accelerating and plasticizing “Citrate-T” additive into composition of the dry mix leads to an increase of rheological properties in expanded foam mass and  time reduction of its drying and curing. An investigation on microstructure of foam-concrete chipping surface carried out with the help of a scanning electron microscope has shown that the introduction of  basalt fiber and redispersible Vinnapas-8034 H powder into the composition of the dry mix promotes formation of more finely-divided crystalline hydrates. Such approach makes it possible to change purposefully morphology of crystalline hydrates and gives the possibility to operate foam concrete structurization process.

The paper proposes a method for assessment of threshold limit and current rates of dilapidation in building elements which is based on the second strength theory. The method is realized in accordance with the criteria of the maximum linear deformations and with due account of reduction in elasticity module value when material creeping occurs. The method is directed on practical assessment of dynamics pertaining to the values of  rejection probability or destruction of building elements in the process of its operation during the period of its life cycle.

In order to assess dilapidation in elasto-plastic elements of buildings it is necessary to make measurements of deformation growth according to external features, determine average deformation at the beginning of building operation and in specified period of time, threshold limit values of complete relative deformation that characterizes maximum allowable element dilapidation with account of plasticity. Further, а percentage dilapidation scale has been formed on the basis of remainder between average values of initial and threshold limit deformations and with due consideration of plasticity, rejection probability or  conjugate conditions with other building elements. So in order to form the percentage dilapidation scale the deformation remainder has been divided by 100 % dilapidation and temporary dilapidation scale has been formed when the remainder is divided by value of element service life. The scales reflect dilapidation rate of the building element through probability growth of its destruction. In this context dilapidated operational period of construction elements and structures should not be included in their rated service life which firstly should guarantee the required security level.

Nowadays main qualitative indices depend on concrete structure formation and curing while constructing cast-in-situ concrete and reinforced concrete structures and especially it concerns winter conditions. Therefore the regime of thermal treatment influences on concrete properties characterizing its strength, porosity, durability, frost resistance etc. In this connection selection of regimes and their corrections are reasonable to be tested while using models. Convenience in mathematical modeling is in reproduction of the operational process in time. However explicit mathematics is obtained only for relatively simple systems or at the cost of specific assumptions and suppositions. In this connection it is expedient to use physical simulation along with mathematical one. The physical simulation presupposes manufacturing, thermal treatment and testing of prototype models.

Development of efficient, scientifically-substantiated technology for thermal treatment of cast-in-situ concrete is impossible without information support and working environment. The proposed mathematical model of thermal treatment for castin-situ structures determines sequence of the operations to be executed. Shapes, geometric dimensions, surface area have been determined in the paper. The required thermotechnical characteristics of formwork systems for structures under concre- ting have been used for making calculations of thermal treatment regimes. The model has taken into account three main stages of thermal treatment: temperature rising, isothermal warming and cooling. The paper provides formulae for their determination including total heat expenditure: for temperature rising of the concrete mix, for thermal treatment of 1 м3 concrete mix, for cement exothermic reaction per 1 м3, for reinforcement heating per 1 м3, for moisture evaporation, for heating of formwork system. The following heat losses have been determined: in the environment, in the process of passing through the exte- rior surface of the formwork, in case of temperature rising in one of the constructive element and per 1 м3 of its concrete mix. The paper reveals determination of hourly heat consumption for a concrete structure as a whole.

The proposed methodology makes it possible to determine the required characteristics of heat treatment process for concrete mixes, to optimize regimes of heat treatment, promptly to make corrections in the created situation, to automatize the process and when it is necessary to make comparison of some solutions in the form of graphics and diagrams.

The article considers the additives use for cold asphalt emulsion mixes. Urgency of the issue consists in the necessity of usage justification and regulation of additive for cold mixes properties adjustment. The article is represented as the general result of analysis of regulatory, literary and other sources related to additive using for CAEM.

The main part of the article proposes and justifies the classification of CAEM additives according to their functional purpose (the main purpose of additive): increasing of strength, water resistance, durability, regulating curing and technological modifiers. Depending on the purpose the criteria of technical efficiency of additive using are presented. For each criteria provided the methods determining one or more quality indicators. The quality indicator changing is indicator of additive efficiency. There is provided the formula determining the efficiency of CAEM curing period reduction additives. As an example provided efficiency calculation and evaluation of additives for regulation (acceleration) CAEM curing according to the previously published experimental data. The efficiency of curing regulating additives was determined according to the function of temporal changes of CAEM compressing strength and dynamic modulus of elasticity.

The article provides the example list of materials that could be or currently used as additives for cold mixes. The conclusion states that proposed classification and criteria give base to purposive regulation of cold asphalt emulsion mixture compositions and their properties.

The problem of low durability of flexible pavement is one of the most important problems of road economy. For example, the actual service life of asphalt pavement in Russia about 3 … 5 years. The bad condition of highways is an obstacle for the development of the national economy and leads to a significant annual economic losses.At present, this problem has no exact solution. Even at the seeming good road conditions of Europe and America the problem of low durability is no less important in these countries. And this problem becomes more and more actual every year.

Our scientific researches allowed to make a hypothesis that the projected of pavements are not have the necessary durability yet not of a stage of designing because in strength calculations did not take into account the vibration of road constructions.

Very actual the vibration loading becomes today as is now significantly changed the nature of loading of pavements. As a result the deflections of a pavements are reduced, but the increased vibration of pavements accelerated processes of destruction and significantly reduced durability.

The theory of vibration destruction developed by the author allows to adjust the vibration, to form the vibration resistance pavements, and also to forecast a residual life of pavements that will more effectively develop repair actions.

The paper presents technology for installation of floor slabs lightened by plastic core drivers which are preliminary stressed under construction conditions.  Efficiency of such constructive solution is justified by the action of preliminary concrete compression in the tensile zone while reducing structure dead weight due to void arrangement.  The paper provides classification of systems for preliminary stress and contains recommendations on selection of the system depending on peculiariar features of the designed construction.  Main products and materials required for execution of works , requirements to stressed wire rope reinforcement, its main characteristics have been considered in the paper.

Principal diagram of the lightened preliminary stressed slab stipulates arrangement of so called  dummy caisson. Strands of reinforcement ropes are located within the framework of bars passing over supporting structures (over vertical bearing structures of  the framework) and voids are formed in the cells between bars by laying hollow plastic items joined together by a cage. The paper presents technological sequence of operations required for arrangement of the lightened preliminary stressed slab, schemes for equipment arrangement and characteristics of the applied devices and units (pushing device for reinforcement ropes, hydraulic jack with delivery hydraulic pump, mixing station, injection pump and others).  Recommendations have been given for execution of works in cold weather. The paper considers problems pertaining to control quality of the materials and items which are supplied to a construction site and directly execution of works on preliminary stress of a cellular slab.

The executed analysis of technology permits to conclude that it is characterized by high level of applicability for import substitution. It is necessary to consider the possibility to apply the technology at objects of various application while comparing it with other constructive solutions according to the main technical and economic indices. 

One of the most prospective directions in preservation  and increase of service live of  road pavements is a construction of  automobile roads with cement concrete surface. Modern tendencies for provision of road construction quality presuppose a necessity to control processes of solidification and subsequent destruction of the material while forming and using cement concrete conglomerate being considered as a basic element of the road surface.  Multiyear practical experience of  automobile road operation using cement concrete pavements reveals an importance for monitoring  such processes as formation and destruction of cement concrete materials. An impedance spectroscopy method has been tried out and proposed as a tool for solution of the given problem.

Experimental samples of cement concrete have been prepared for execution of tests, graded silica sand and granite chippings with particle size from 0.63 to 2.5 mm have been used as a fine aggregate in the samples. Dependencies of resistance (impedance) on AC-current frequency  have been studied for samples of various nature and granulometric composition. The Gamry  G300 potentiostat has been used for measurement of complex impedance value. A spectrum analysis and calculation of equivalent circuit parameters calculation have been carried out while using EIS Spectrum Analyzer program.

Comparison of impedance spectra for the prepared cement concrete samples have made it possible to reveal tendencies in changing spectrum parameters during solidification and subsequent contact with moisture in respect of every type of the sample. An equivalent electrical circuit has been developed that  characterizes physical and chemical processes which are accompanied by charge transfer in cement concrete conglomerate. The paper demonstrates a possibility to use an impedance spectroscopy for solution of a number of actual problems in the field of cement concrete technology problems. Particularly, the problems are connected with usage of technogenic wastes (e.g. granite chippings as a fine aggregate) and optimization of mineral and granulometric mix composition for road pavement. Development of an approach for investigation of properties on cement concrete materials on the basis of an impedance spectrum analysis will permit  quantitatively to characterize processes which are occurring in them including such processes as concrete solidification and corrosion.

The road-transport complex objectively reflects the essence of efficient transportation process which is carried out by transport facilities along the highways. The complex  emphasizes an equivalent contribution of transport facilities and highways in a unified transportation process. Efficiency of the state economy rigidly depends on availability of the developed and well-functioning network of highways. Countries with the developed economy which have generally finished creation of national highway networks continue to invest money in public road systems that stimulates development of industrial sectors, agriculture and trade, etc. Their progress and efficient functioning is possible only with the balanced, overall development of the road-transport complex of the country. Functioning of the road-transport complex is inextricable connected with the operation of automotive transport and road infrastructure. Interaction of these two components of the unified economic system is determined by technical characteristics of the automotive transport and transport and operational indices of  the highways. Development of methods for optimum organization of management for functioning of the road complex is considered as an important problem of the national economy while forming market economy mechanisms. Further growth of capital expenditures including  investments will be needed in order to ensure such road conditions that meet the requirements of modern and perspective road traffic. Management of the highway network conditions presupposes a selection of such set of regulatory impacts on road conditions which will allow to minimize expenses in the road-transport complex. Elaboration and realization of the most efficient repair measures serve as such regulatory impact. The purpose is achieved while solving the problem pertaining to minimization of expenses on  transportations in the road-transport complex in the process of the realization of the most efficient repair measures at the stage of highway life cycle.

A prospective method for protection of  bridges and tunnels against aggressive water action is surface waterproofing on the basis of an organo-mineral binder. Its structural strength can be increased by introduction of particles which are similar to the size of  asphaltenes and an elasticity of disperse medium has been increased due to introduction of polymers. These theoretical suppositions point out the possibility for simultaneous provision of flexibility at low temperatures and high heat resistance for mastics on the basis  of organo-mineral binders. In this regard a goal has been set to obtain a mastic high flexibility and high heat resistance  while using finely divided activated peat ash.Rubber crushed in accordance with ТУ (Technical Specifications) 38.108035–87,  divinyl-styrene thermoelastoplast DСT-30Р-20ПС,  bitumen of grade 20/30 in accordance with СТБ ЕН 12591–2010, ash from burning peat at the Lida Peat Briquette Plant, multi-purpose industrial oil of solvent refining with high viscosity index, super-plasticizer – sodium salt which is a condensation product of aromatic carbon sulfo-oxidation with formaldehyde and neutralization with the help of sodium hydroxide (type 1) have been used in order to obtain the stated objective. While using these materials compositions and technology for preparation of organo-mineral mastics have been developed in the paper. Their tests have shown that a modification of finely divided  mastics carried out with the help of peat ash which is activated by super-plasticizer НСПКСАУсФ-1, various polymer additives, contributes to an increase in their heat resistance, elasticity, water resistance, and also allows to control their technological and operational characteristics. The paper has experimentally confirmed that peat ash can be successfully used for preparation of high-quality waterproofing mastics which are so necessary for  protection of bridge and tunnel constructions. Its use will provide not only a great economic impact, but also contribute to improvement of ecological situation in the areas of peat burning and ash disposal.