Introduction. The results of research of physical and mechanical characteristics of non-metallic composite basalt reinforcement obtained by researchers, in particular, the shear strength of basalt reinforcement, coupling of basalt reinforcement to concrete, leaching of basalt fiber, durability of structures reinforced with non-metallic composite basalt reinforcement.
Problem Statement. In the road industry, the main part of the costs for repair and restoration of reinforced concrete structures of bridges and overpasses is associated with corrosion of metal reinforcement. The use of non-metallic armature is a promising fundamental solution to this problem. Technical characteristics allow to apply basalt armature for road construction, at strengthening of bridges, for enclosing designs, in the designs which are exposed to aggressive environments.
The effect of the use of basalt reinforcement is obtained, in particular, from reducing the cost of construction through the use of reinforcement of smaller diameter (hereinafter Ø) compared to metal while providing the necessary strength characteristics, reducing the weight of structures with such reinforcement. Also, due to the absence of certain types of corrosion of the armature during operation, the durability of the structure increases, reduce or eliminate certain types of repair work.
However, the use of non-metallic composite basalt reinforcement of periodic profile, made of basalt fibers, designed for reinforcement of concrete structures of transport structures, is constrained by the lack of a sufficient number of research results of the characteristics of such reinforcement. On the basis of such researches it will be necessary, further, to make changes in norms on designing, standards on test methods, etc.
Purpose. Investigate the armature of one of the main manufacturers, which were manufactured at the time of the study in Ukraine. Determine the geometric dimensions, mass, color, temporary resistance, elongation after rupture of the basalt reinforcement of the periodic profile with a diameter of 6 mm, 10 mm. To process the results of tests of physical and mechanical characteristics of non-metallic composite basalt reinforcement of periodic profile with a diameter of 6 mm, 10 mm, analysis of test results. Develop, based on the conclusions of the analysis of test results, proposals for the requirements for non-metallic composite basalt reinforcement for public transport structures.
Materials and methods. Experimental studies of physical and mechanical characteristics of basalt reinforcement of periodic profile type A, nominal diameter 6 mm, 10 mm, manufactured according to TU U V.2.7-25.2-34323267-001, in particular, the curvature of the bar, surface quality, color of reinforcement, inner diameter reinforcement, temporary resistance, elongation after breaking.
Results. As a result of researches it is established that curvature of a bar, quality of a surface, color of armature correspond to TU U V.2.7-25.2-34323267-001. The inner diameter of the valve, for individual bars, exceeds the permissible deviations within 0.3 mm in accordance with TU U V.2.7-25.2‑34323267-001, DSTU B V.2.7-312:2016. However, as a result of the analysis of the obtained mechanical characteristics it was found that such deviations do not significantly affect the values of the mechanical characteristics of the tested samples (they are not less than necessary).
However, in the future, when using basalt reinforcement, it is necessary to check such reinforcement for compliance with the requirements of DSTU B B.2.7-312:2016 and compliance must be ensured.
Determined for basalt reinforcement temporary resistance, elongation after breaking, respectively: for Ø 6 mm ― 1 105 MPa and 2,13 %; for Ø 10 mm ― 1 068 MPa and 2,10 %.
Conclusions
- Analysis of research on non-metallic composite reinforcement has shown that in recent years, scientists have paid considerable attention to reinforcement, as they see the prospect of its widespread use in the future. Studies of basalt reinforcement have shown that it has high strength, low density, has sufficient resistance to alkaline environment.
- As a result of researches of armature with a diameter of 6 mm and 10 mm it is established that curvature of a bar, quality of a surface, color of armature correspond to TU U V.2.7-25.2-34323267-001, DSTU B V.2.7-312:2016. The inner diameter of the valve, for individual bars, exceeds the permissible deviations within 0.3 mm (according to TU U V.2.7-25.2-34323267-001 and DSTU B B.2.7-312:2016). However, as a result of the analysis of the obtained mechanical characteristics it was found that such deviations do not significantly affect the values of the mechanical characteristics of the tested samples (they are not less than necessary). However, in the future, when using basalt reinforcement, it is necessary to check such reinforcement for compliance with the requirements of DSTU B V.2.7-312:2016 and compliance must be ensured.
- Defined for basalt reinforcement temporary resistance, elongation after breaking, respectively: for Ø 6 mm ― 1105 MPa and 2,13 %; for Ø 10 mm ― 1068 MPa and 2,10 %.
- The strain corresponding to the maximum static tensile load (Pmax) before the failure of basalt reinforcement samples was set when testing the reinforcement sample Ø 6 mm and is near 1153 MPa, which corresponds to the tensile strength of high-strength steel reinforcement class A-1000. The relative elongation of the basalt reinforcement δ is in the range from 2,0 % to 2,3 %, and is proportional to the δ of the reinforcement A-1000, which is equal to 2,0 %.
- The results of tests for static loads show high performance characteristics of basalt reinforcement Ø 6 mm and Ø 10 mm, which is a prerequisite for the use of the tested reinforcement in the construction of transport facilities.
