| In order to improve the concrete shortcomings of brittleness, poor toughness and the easy to crack, improve the bonding strength of the fiber and concrete, while improving concrete strength, on the basis of considering the three, mix steel fibers in concrete, and use magnetized water instead of ordinary water to preparate magnetized water steel fiber reinforced concrete under three kinds of flow velocity (0.6m/s,1.2 m/s and 2.1 m/s), and four kinds of steel fiber volume fraction (0.6%,1.2%,1.8% and 2.4%) on magnetic induction 285mT. In this paper, study flexural strength, impact resistance and crack resistance of plain concrete, magnetized water concrete, steel fiber reinforced concrete and magnetized water steel fiber reinforced concrete through relevant research.Flexural strength test shows that the flexural strength growth rate of steel fiber reinforced concrete when steel fiber volume fraction is 2.4% can respectively reach 54.83% and is best; when the flow velocity is 0.6 m/s,1.2 m/s and 2.1 m/s,the flexural strength of magnetized water steel fiber reinforced concrete is better than steel fiber reinforced concrete under the same; when the flow velocity is 2.1m/s and steel fiber volume fraction is 1.8%, the flexural strength growth rate of magnetized water steel fiber reinforced concrete is best,compared with steel fiber reinforced concrete,its flexural strength growth rate can reach 27.38%.The impact resistance test which flow velocity and steel fiber volume fraction are variable is carried out with 20 different concrete mix proportions, a total of 120 specimens pie. Test shows that initial crack and failure impact resistance times of plain concrete is substantially equal and small. initial crack and failure impact resistance times of magnetized water concrete presents a increase tendency with flow velocity increasing, when the flow velocity is 2.1 m/s, impact resistance times is maximum, the initial crack times increased 263.5 times,3.8 times for the plain concrete, failure impact resistance times increased 271 times,3.9 times for the plain concrete. For steel fiber reinforced concrete, with increasing fiber volume fraction of steel fiber reinforced concrete, the curve of initial crack and failure impact resistance times presents a increase tendency, and between 1.2% and 1.8% growth rate of the largest. For magnetized water steel fiber reinforced concrete, initial crack and failure impact resistance times is better than steel fiber reinforced concrete, and initial crack and failure impact resistance times of magnetized water steel fiber reinforced concrete presents a increase tendency on the whole with flow velocity increasing,and when flow velocity is 2.1m/s,its reachs maximum.Early cracking test shows that fracture length and width of magnetized water concrete are reduced significantly,compared with plain concrete,and the early crack limiting grade is first one; the capacity of crack resistance of magnetized water steel fiber reinforced concrete strengthens more obvious, In length and width, cracks reduce by a big margin, the coefficient of crack decrease of magnetized water steel fiber reinforced concrete is 97.5%, the crack limiting grade is first one, the effect of crack resistance is very significant. |
