Technological advantages of steel fiber:
Usage of steel fiber has certain advantages over traditional reinforced concrete, because when certain quantity of steel fiber (25-50 kg/m3) is added in the concrete mix, fiber is distributed uniformly on the whole volume and, as the result, three-dimensional structure is formed. This structure with steel fiber can bear up high loads, preventing microfissure opening in the concrete monolith.
Economic advantages of steel fiber.
Usage of steel fiber for concreting of building projects means saving of material and time costs. Time and work force used for installation of standart fastening are economized, reinforcing materials should not be placed on the concreting area, the possibility to produce big concrete articles by fewer labour costs appears. Concrete constructions, which structure contains steel fiber, have better performance, namely: bending tensile strength is increased in 1,5-2 times; ultimate tensile strain is increased in 20 times. Moreover, concrete that contains fiber has better resistance to the climatic and physical influences.
The technology of work with fiber.
Recommendations concerning the quantity of steel fiber in the concrete:
In case of light dynamic load - 15-30 kg/m3
In case of average dynamic load - 30-40 kg/m3
In case of high dynamic load - 40-75 kg/m3
Srtong patterns – 75-150 kg/m3
Steel fiber is added in the mix during concrete preparation. In order to add steel fiber, special conveyor is used. However you can add steel fiber manually, but you should avoid penetration of fiber lumps in the concrete mix.
Concrete placement with steel fiber.
Concrete with steel fiber is fitted mechanically with the help of vibration machinery or special paving machines for steel fiber and concrete. Manual concrete placement with steel fiber is possible on the small areas. When steel fiber is used, concrete density is increased, concrete surface is plain and concrete physical properties are improved.
Final handling of the concrete surface can be made both mechanically with the help of cement trowel and manually with the help of hand trowel. Fiber-concrete flatting should be made at once after concrete mix pouring, so that plain surface without projecting parts (so called "hedgehogs") can be obtained. Wave fiber is more inclined to the "hedgehogs" formation, at the same time it prevents concrete shrinkage. Fiber with curved edges is less inclined to the "hedgehogs" and is considered the most widespread type of wire fiber.
Steel fiber usage.
Steel fiber reinforces two main useful properties of concrete: the rigidity and strength. These two main properties of concrete with steel fiber allow designers to develop constructions, that can withstand heavy loads. Concrete, which contains steel fiber (fiber concrete) is used in the equipment foundation, plates of airdrome runway marking, rapid motorways Бетон, в состав которого входит стальная фибра (фибробетон), используется в фундаментах оборудования, плитах взлетно-посадочных полос аэродромов, скоростных автострад, в торкретбетоне, противооползневых плитах и береговых сооружениях, сейсмоустойчивых конструкциях, для сооружения хранилищ ценностей в банках, в гражданском и военном строительстве, при устройстве наливных полов.
- is wire segments D= 0,7-1,2 mm, length 25 - 60 mm. Special configuration of edges provides tight adhesion to concrete. Steel fiber is made of low carbon wire with tensile strength 900-1500 N/mm2.
Steel fiber is used for concrete reinforcement of the entire volume, increasing the stiffness and strength of concrete monolith.