Design Models of the Bearing Capacity of the Support Sections of Basalt-Concrete Beam Structures

Abstract

Abstract. In the past decade, structures with non-metallic composite reinforcement (FRP) find more and more widespread use in construction practice, especially in buildings and structures for special purposes. Due to its high strength, resistance to chemical and physical corrosion, dielectric and diamagnetic properties, low weight and low thermal conductivity, FRP is increasingly replacing steel reinforcement. However, the wider use of concrete structures with FRP is constrained by insufficient knowledge of the features of their work, insufficient regulatory support and little experience in operating these facilities. Practice has shown the promise and economic feasibility of using FRP in road, hydraulic engineering, transport construction, in the construction of bridge spans, treatment facilities, chemical and food industry facilities, and foundations in an aggressive soil environment. At the same time, the prospects for using basalt-plastic reinforcement (BFRP) are primarily due to the low cost of the main raw material, basalt fibers, due to the presence of significant reserves of basalt in the world. The basic principles of calculation of bending structures reinforced with FRP, in all foreign standards, as well as in the domestic Manual, are the same as for elements with steel reinforcement. The design models of the bearing capacity of the bearing sections of concrete beams reinforced with BFRP are considered. The bearing capacity of inclined sections of elements with large and medium shear spans should be determined by an inclined crack using variable coefficients , taking into account the real length of a dangerous inclined crack , a significant reduction in tensile stresses in transverse reinforcement to . The bearing capacity of the support sections with small shear spans must be determined as for short cantilevers along an inclined compressed strip between the concentrated force and the support using a variable coefficient . This approach provides satisfactory convergence between the calculated and experimental values of the bearing capacity of inclined sections (coefficient of variation BFRP.

Simulation of Design Reliability and Bearing Capacity of Normal and Oblique Sections of Span Prestressed Reinforced Concrete Structures

“…As a result of processing the data obtained in the works [12,13,14], extracting insignificant and recalculating the remaining coefficients with the help of software package COMPEX, which was developed in the Odessa State Academy of Civil Engineering and Architecture, adequate mathematical models of design reliability indexes β, bearing capacity Мu of normal (series А) and oblique sections of rectangular beam reinforced concrete structures with prestressed bar reinforcement that were determined according to the Eurocode 2 [3] in edition of DSTU B V.2.6 156:2010 [2] VRd, c (series C), as well as mathematical models of design reliability indexes β and bearing capacity of oblique sections, which are failed by oblique compressed band V according to the author's technique [15] (series E) were received: ( )…”

“…Design values of reliability index βF* on the strength of oblique sections VF* of span reinforced concrete structures with prestressed wire reinforcement and small spans of shear, which are failed by oblique compressed band according to the author's technique [15], can be determined by mathematical models Eq. 11, Eq.…”

“…From the theory verified experimentally by V.M. Karpiuk [15] it is known that beam structures with a small span of shear can be failed by oblique compressed band. The reliability index and bearing capacity of oblique sections of such elements, which are failed according to this scheme, can be represented by adequate mathematical models Eq.…”

“…The bearing capacity of oblique sections of beam structures with small spans of shear VE, which was determined according to the author's technique [15], will increase relative to the average value 199,86 kN (Eq. 6):…”

“…3. Dependence of reliability index β and bearing capacity of oblique sections V [15] of span prestressed reinforced concrete structures, which are failed by oblique compressed band, on the longitudinal reinforcement ratio (а), the concrete class (b), the class of prestressed bar reinforcement (c) and complex influence of these constructive factors (d) on β and V…”