Abstract. The present paper investigates mechanical properties of composite polymer rebar. The values of basic strength and strain properties of composite rebar when exposed to static axial tensile and compressive load were determined experimentally. The strain and stress values in composite rods were measured using high-precision sensors. The stressstrain diagram of glass-and carbon-fiber composite rebar under static compression and tension were presented, including general data of its stress and strain limits and typical failure schemes. Based on the literature review analysis authors proposed the coefficients of dynamic hardening of composite rebar under short-term dynamic loading.

Strength and deformability of concrete beams reinforced by non-metallic fiber and composite rebar Abstract. Production of durable and high-strength concrete structures with unique properties has always been crucial. Therefore special attention has been paid to non-metallic composite and fiber reinforcement. This article describes the experimental research of strength and deformability of concrete beams with dispersed and core fiber-based reinforcement. As composite reinforcement fiberglass reinforced plastic rods with diameters 6 mm and 10 mm are used. Carbon and basalt fibers are used as dispersed reinforcement. The developed experimental program includes designing and production of flexural structures with different parameters of dispersed fiber and composite rebar reinforcement. The preliminary testing of mechanical properties of these materials has shown their effectiveness. Structures underwent bending testing on a special bench by applying flexural static load up to complete destruction. During the tests vertical displacements were recorded, as well as value of actual load, slippage of rebars in concrete, crack formation. As a result of research were obtained structural failure and crack formation graphs, value of fracture load and maximum displacements of the beams at midspan. Analysis of experimental data showed the effectiveness of using dispersed reinforcement of concrete and the need for prestressing of fiberglass composite rebar.

No abstract

The article presents a method for calculating the strength of concrete elements with non-metallic fiber, rod and external reinforcement. The algorithm and the calculation program are shown, which are based on the use of a nonlinear deformation model of the normal section of such elements, taking into account the real deformation properties of materials under static and short-term dynamic loading.

Many new developments in the field of creating promising building materials relate to polymer fiber composites for reinforcing concrete constructions. The most effective use of such composites is provided by carbon fiber reinforcement. To date, the issues related to design, calculation and use of concrete constructions with carbon composite reinforcement under dynamic compressive loading have not been well studied. Purpose: The purpose of this study is to determine strength of dynamically loaded concrete constructions reinforced with carbon fiber using different methods of modification of deformation properties of concrete. Methodology: Experimental studies include testing two concrete columns with steel rod reinforcement and six concrete columns modified by carbon fiber and carbon composite reinforcement. The columns are tested under axial static and dynamic compressive loads. Research findings: The resulting longitudinal deformations of concrete and carbon-composite reinforcement and the limiting compressive force are determined. Value: New experimental data are obtained for the concrete column strength reinforced with carbon composite rods. The experimental results indicate the effective resistance to compression of carbon composite reinforcement. This phenomenon is observed in the case of carbon fiber and carbon composite reinforcement of compressed concrete constructions under the dynamic load. Practical implications: Resistance of carbon composite reinforcement to the dynamic compression affects the concrete strength, especially when its deformation properties are modified by carbon fiber and carbon composite reinforcement. The obtained results can be used in strength calculations of concrete constructions under the dynamic load.