PROPOSALS FOR IMPROVING THE UKRAINIAN CONSTRUCTION NORMS OF STEEL FIBER REINFORCED CONCRETE CONSTRUC-TIONS

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Visnyk LNAU: Architecture and Farm Building 2018 №19: 38-40

PROPOSALS FOR IMPROVING THE UKRAINIAN CONSTRUCTION NORMS OF STEEL FIBER REINFORCED CONCRETE CONSTRUC-TIONS

V. Bilozir, Candidate of Technical Sciences
Lviv National Agrarian University

https://doi.org/10.31734/architecture2018.19.038

Annotation

In the Ukrainian and Russian construction norms, the diagram of tension is taken rectangular in compressed and extended zones of the bending element. Moreover, the theoretical resistance of steel fiber reinforced concrete are deter-mined by calculation. This is the fundamental difference between these norms from the norms of developed countries. All the above explains the reason for reas-sessing the bearing capacity of the bending steel fiber reinforced concrete element, calculated according to domestic norms, which is confirmed both theoretically and experimentally.

An essential disadvantage of Ukrainian norms in comparison with Russian is that they do not have a method for calculating pre-stressed structures, because the prestress gives rise to a radical increase crack resistance, which is extremely important from the point of view of ensuring corrosion resistance of steel fiber reinforced concrete elements. There is no such methodology in foreign recom-mendations, which are not yet design standards.

It is advisable to make changes and additions to Ukrainian construction norms of steel fiber reinforced concrete structures taking into account the domes-tic experience of experimental-theoretical researches and experience of foreign scientists: to provide classes of steel-reinforced concrete which would be charac-terized not only by cube and cylindrical strength but also by the residual tensile strength for crack widths of 0.5 mm and 3.5 mm; to provide in the norms making experimentally justified idealized diagrams of deformation of steel fiber rein-forced concrete under tension and compression for all types of fibers; transition to the deformation method of calculating the constructions at the boundary states of the first and second groups; to provide proposals for the calculation and construc-tion of pre-stressed combined reinforced steel fiber reinforced concrete construc-tions.

Key words

steel fiber reinforced concrete, calculation, limit state design, diagrams of deformation, construction norms

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