Physico-chemical methods of the study of hydrated cement by mechanically activated binding substance with organo-mineral additive (microsilica + C-3) were presented. It was explored the influence of the additive into the kinetics of formation lowly-basic calcium hydrosilicate. The experiment conducted in accordance with a three-factorial D-optimum plan enabled to establish an influence of blending and technological factors (x1 – content of microsilica in the binder - 5±5%; x2 – binder consumption in concrete - 450±100 kg/m3; x3 – specific area (Ssp) of Portland cement 400±100 m2/kg) on physical and mechanical properties of concrete (compression strength, water absorption). It was established that the use of the mechanically activated blended Portland cement of general purpose with an organomineral additive (microsilica+C-3) makes it possible to obtain high-strength concretes which compression strength on the 28th day reaches 120 MPa. Optimization of concrete mixes was achieved on the basis of obtained mathematical models that reflect the influence of blending and technological factors on physical and mechanical properties of a high-strength concrete.

The article discusses the properties of disperse reinforced claydite concrete on mechanically activated slag-portland cement with the addition of polycarboxylate superplasticizer Relaksol-Super PC. The idea of making a high-mobile claydite concrete mix with a settling of concrete cone 45 to 50 cm is substantiated. Particular attention is paid to the study of the effect of mechanical activation of the binder on the kinetics of the increasing in the strength of claydite concrete. The results of researches indicate that introduction of basalt fiber into slag-portland cement together with mechanical activation of binder allows to increase the impact strength of concrete by almost 1.7-1.9 times in comparison with the reference and to provide frost resistance of concrete at least than 350 cycles of alternating freezing and thawing.

The article describes a developed technique of a numerical simulation of the stress-strain state of complex-reinforced elements, which allows you to create models of double-span continuous. The performed experimental and theoretical studies allowed us to carry out the testing of the developed design model and to justify the reliability of the proposed numerical simulation methodology. The results of the experimental studies were compared with those of the theoretical studies. The theoretical calculus algorithm was developed by using the finite element method. Theoretical calculations were performed by using the mathematical-graphical environment software system LIRA-SOFT and the mathematical and computer program MATLAB. On the basis of the experimental research, the iso-fields of displacements and stresses in the materials of an eccentrically compressed beam with a small bend of the slab were constructed, which collapse behind the inclined narrow strip of concrete and displacements and stresses in the materials of the eccentrically stretched beam, which is destroyed due to the yield of the upper mounting armature.

The results of experimental investigations of deflections of continuous reinforced concrete elements are obtained, empirical dependences are deduced. Comparison of the deflection values with the results of calculations by the author’s method of NIISK (Bambura A.M.), adapted deformation model of OSACEA, what was realized with the help of the mathematical program MATLAB and also the algorithm of theoretical calculations of the finite element method was developed using the mathematical-graphical environment of the LIRA-SOFT software complex. The results of experimental investigations of deflections of continuous beams were compared with theoretical data (graphical representations of displacements in the form of isofields were obtained).The finite element calculation allowed to monitor the stress-strain state of the test beams at all stages of work, which made it possible to compare the obtained experimental values of the deflections with the designed ones. The performed experiments confirmed the feasibility of taking into account the shear deformations on the supporting sections in determining the deflections of reinforced concrete beams.

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