Experimental research of the tensile strength of concrete reinforced with basalt fiber

Non-metallic composite fittings are increasingly used in modern construction due to their high mechanical characteristics, corrosion resistance, durability in concrete and aggressive external environments, and other properties. At the sametime, usually, non-metallic composite reinforcement is used in the form of rods with the main supporting element in the form of basalt, glass, aramid or roving made of other materials, which is thin fibers with a diameter of 7...20 mm.The specified roving, as an element of reinforcement of concrete structures, will be used in the form of fiber to a much lesser extent, although it is a real alternative to traditional steel fiber with all the advantages of fiber reinforcement, to which corrosion resistance is also added. The limited number of experimental explains the current situation andtheoretical studies of non-metallic fiber reinforcement, in particular, tensile strength, which is one of the main advantages of fiber reinforcement of concrete.This article presents the results of experimental studies of the tensile strength of concrete reinforced with fiber from basalt roving with a diameter of 16 μm and a length of 24 mm, which included bending tensile tests of three series of concrete samples with a strength class of compression, respectively, C20/25, C25/30, C30/35 and percentage of fiber reinforcement within 2.0...8%.As a result of the conducted research, it was established that the fiber reinforcement from the baseboard roving leads to an increase in the axial tensile strength of concrete. At the same time, the most intensive increase in tensile strength took place when the percentage of reinforcement was increased in the range of 2.0...4.0%. With a further increase in the percentage of reinforcement in the range of 6.0...8.0%, this growth stopped, which indicates that fiber reinforcement in the range of 2.0...4.0% is the most effective, regardless of the class of concrete in terms of compressive strength.Other things being equal, the increase in axial tensile strength of concrete with an increase in the percentage of fiber reinforcement within the limits of 2.0...8.0% is 15...20% compared to concrete without reinforcement.