strength

The application of engineering cementitious composites (ECC) – a specially developed class of cement-based material reinforced with fibers – allows to enhance the loading capacity, stability under static and dynamic influences, as well as durability of building structures due to controlled cracking process. The design of engineering cementitious composites is based on the concept of micromechanics, which includes the strength and energy criteria of deformation strengthening throughout the wide range from the macro- to the nanostructural level.

Every construction is influenced by different factors during operation. As a result, there are various defects and damage of these elements, which affects their operating condition. One of such defects is the corrosion of the working rebar. Investigation of samples with corrosion is a complicated and labor-intensive process. Instead of corrosive effects, we perform controlled valves of damaged. In this way, we obtained experimental samples with a fixed value of reducing the diameter of the valve.

In many countries (Japan, USA, China, Poland, etc.) the studies of the influence of laser radiation on the surface of various building materials are being carried out for a long time, including the military purposes. Most attention has been paid to the interaction of laser radiation with the surface of metals.

The relationship between spalling formation on model wheels tread surface and cyclic fracture toughness of steels with nitride strengthening is study. It is shown that the nitride strengthening of wheel steels has a positive influence on damage resistance of surface rolling of model wheels. To improve the serviceability of wheel steels with nitride strengthening indicated the need to optimize their chemical composition providing content of carbon in the range of 0.50...0.55 %, vanadium — 0.08...0.12 % and nitrogen — 0,008...0,015 %.

The results of studies of the impact strength, temperature factors and parameters of cutting tool geometry on the formation of the stress-strain and thermodynamic state of surfaces with different types of engineering materials in the cutting process are described in the article. Analysis of simulation modeling of power, temperature and deformation parameters is the basis for making of forecasting models of influence of the structure and process parameters on the formation of complex operational properties of the product.

There is investigated the effect of carbonate-containing and sulfate salt processing wastes on the properties of cementitious systems and aerated concretes based on them.

In this article describes theoretical and experimental research of contact seams in the repair or strengthening concrete elements using concrete, sprayed-concrete anchors and substrate binding.

The effect of carbonate additives on physical and mechanical properties of type II Portland cement was investigated. It was shown that calcium carbonate which is added as fine ground mineral additive, participates in the phase composition and microstructure formation of Portland composite cement paste.

The main results of experimental studies of strength, bearing areas’ are usually uncut, pre-stressed, stretched and eccentrically compressed reinforced concrete beams. Тhe identified of the stated constructions’ bearing areas’ new destruction patterns and the establishment of their dependence on the research factors’ corresponding ratio; the development of new general engineering methods of the studied elements’ bearing areas’ durability calculation based on the choice and the alternating consideration of the most probable destruction schemes.