The article reflects the results of experimental studies of carbon-fiber reinforced concrete under compression and tension. Qualitative change of concrete strength and stress-strain properties at its dispersed reinforcement with carbon fibers is fixed. As a result of the statistic processing of experimental data, analytical dependencies for determination of carbon-fiber reinforced concrete main strength and stress-strain characteristics under compression and tension are suggested. Calculation diagram of non-linear straining of carbon-fiber reinforced concrete at static effect is presented.

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Road trains (RT) are the main transport in agriculture. However, their accident rate is quite high. In the vehicles movement research their design characteristics and operating modes are mainly improved. The main way to reduce the accident rate remains the speed limit. The authors proposed methods (confirmed by the issued patents) for ensuring the stability of the RT movement by changing the design of trailer devices. The purpose of this work is to form a mathematical model for assessing the stability of the RT movement in the presence of side effects (modeling of sharp turns, impacts). Methods of analysis and synthesis, mathematical analysis, and vector geometry were applied. The process of RT yawing on the highway is split into a number of stages, for which the laws of changing its geometry and kinematics are formulated. Side effect leads to increase in the RT impulse (lateral oscillations increase the speed), or to a violation of stability (the movement amplitude goes beyond the highway or tipping). This model can be used to analyze the stability of the RT movement and evaluate methods to influence it in order to reduce the probability of accidents.

The article describes application of precast, cast-in-situ and composite structures on construction site. Importance of Analysis of Russian (SP) and European design standards (EuroCodes) is underlined. Historical review of Russian codes for composite reinforced concrete structures is given. Methods of composite structures calculating according to current Russian Codes are given. Ultimate and service limits states are listed for describing structures. Advantages and disadvantages of cast-in-situ, prefabricated and complex technologies are discussed. Comparison of prefabricated, monolithic and complex technologies is given on example of intermediate floor slab. Examples of sections of prefabricated reinforced concrete composite structures are summarized. Composite structures detailing is given on example of real project of Parking building of Okhta-Mall shopping and entertainment center, Saint-Petersburg. Constructive solutions are presented that increase the bearing capacity and resistance to progressive collapse of structures. Manufacturing photos of prefabricated ready-made reinforced concrete slabs as a part of future composite slab are presented. Examples of detail drawings for composite concrete slabs, executed in accordance to Eurocode, are given. Suggestions for improving the existing Code of Practice are given. Reference to similar scientific papers is presented related to composite reinforced concrete elements. Article is developed with financial and technical information support of AFRY Oy Finland.

In developed countries only loss of property because of fire makes annually up to 2% of their national income [9, 15]. The bearing capacity of reinforced concrete structures at high temperature impact is lost within several dozens of minutes [1, 3, 5, 10, 12, 18, 25]. Disappointing statistics of increase of both the number of fires and the scope of damage due to them aggravates the actual problem of determination of reinforced concrete structures fire-endurance. The main problems and methods of evaluation of reinforced concrete structure fire resistance are stated. Within the framework of block approach to evaluation of strain of flexural reinforced concrete elements with cracks, design model of reinforced concrete thermo-force resistance is made. Extended nomenclature of influences of high temperature at fire on decrease of performance of bearing reinforced concrete structures is considered. Empirical dependencies of strength and strain characteristics of concrete and reinforcement on high temperatures are used. Proposals on specification of evaluation of fire resistance of statically indeterminate reinforced concrete structures are formulated.