Frost Resistance Of Aligned Steel Fiber Reinforced Concrete

Steel fiber reinforced concrete attracted scholars’ attention after being put forward as a composite material. The enhanced effect of steel fire on concrete has been widely studied. In recent years, domestic researchers proposed that aligned steel fiber reinforced concrete can be producted by the technology of electromagnetism making steel fibers along the same direction. At present,people has a little of knowledge of aligned steel fiber reinforced concrete, so that most of results focused on its physical and mechanical properties and its durability is rarely been reported. Therefore, this paper made the following work:(1)This experiment studied on the frost resistance of common concrete, conventional ordinary steel fiber reinforced concrete and aligned steel fiber reinforced concrete. according to weight loss and relative dynamic modulus of elasticity during the fast freeze-thaw test, it shows that the frost resistance of steel fiber reinforced concrete is better than common concrete and aligned steel fibers are equal to randomly distributed steel fibers for enhancing the frost resistance of concrete.(2)This experiment researched on flexural strength and compressive strength of all sorts of concrete before and after freezing and thawing. The bending and axial compressive strength test for undergone different cycles of freezing and thawing concrete specimens indicated that :the flexural loss rate of aligned steel fiber reinforced concrete is lower than randomly distributed steel fiber reinforced concrete after freezing and thawing; the axial compressive strength of concrete gone down as the increasing number of cycles of freezing and thawing, the degree of reduction of Steel fiber reinforced concrete is apparently lower than common concrete, while aligned steel fiber reinforced concrete and randomly distributed steel fiber reinforced concrete are similar(3)Analyzed freezing resistant mechanism of concrete by damage mechanics and explain the similarity between cycles of freezing and thawing and low cycle fatigue effect. Analysis on the improvement of the internal cracks of concrete and the fatigue effect strengthening mechanism of concrete shown that steel fibers can improve the frost resistance of concrete.