Ефективність використання фібробетону в сталебетонних балках

Abstract

UA: У статті розглядається ефективність використання фібробетону в сталебетонних балках. Для цього підбирається склад звичайного бетону, який за міцністю відповідає фібробетону. Проведено аналіз видів фібр і пояснюється доцільність використання сталевих і базальтових волокон для несучих конструкцій.

EN: The article discusses the effectiveness of using fiber concrete in reinforced concrete beams. An analysis of fiber types is provided. Fibers can vary in terms of material, shape, length, and other characteristics. The main types of fiber reinforcement by fiber type are: steel fiber, polymer fiber, basalt fiber, glass fiber, and carbon fiber. The feasibility of using steel and basalt fibers for load-bearing structures is explained, and the optimal content and dimensions of steel and basalt fibers are proposed. The concrete mix for concrete and fiber concrete had the following composition: Portland cement M 400 – 437.5 kg/m3 , crushed stone fraction 5-10 mm – 1158.12 kg/m3 , river sand – 552.6 kg/m3 , water – 210 l/m3 . To determine the prism strength, Chilyabinsk steel fiber was used at a rate of 32.536 kg/m3 of concrete. To determine the prism strength of concrete with basalt fiber, 12 mm long fiber was used, which was added in an amount of 0.2% of the weight of cement. To calculate the load-bearing capacity of reinforced concrete structures, as well as when calculating composite elements with elastic-plastic layers and elastic-plastic shear connections, a simplified limit equilibrium method developed by A.A. Gvozdev is widely used. The calculation was performed based on the action of a concentrated force and the action of a distributed load. The load-bearing capacity was calculated based on the strength of the normal cross-section and the strength of the contact between the sheet and the concrete. For all types of beams (without fiber, with the addition of basalt fiber, with the addition of steel fiber), both under the action of a concentrated load and under the action of a distributed load, destruction occurs along the normal cross-section. The addition of fiber allows for a slight increase in the effective load.