Application of steel fiber in concrete

1.Introduction of steel fiber

The properties of steel fibers are very different due to different production methods. For example, the tensile strength of cold-drawn steel wire is 380-3000MPa, the tensile strength of cold-rolled strip shearing method is 600-900MPa, and the steel ingot milling method is 700MPa; molten steel condensation Although the method is 380MPa, it is suitable for producing heat-resistant fibers. Mortar or concrete reinforcement uses thin steel wires with a certain length and diameter. Commonly used long straight steel fibers with a circular cross-section have a length of 10 to 60 mm, a diameter of 0.2 to 0.6 mm, and an aspect ratio of 30 to 100.

If you want to increase the interfacial bonding between fiber and mortar or concrete, you can choose various special-shaped steel fibers. The cross-sections are rectangular, zigzag, and meniscus; the cross-sectional dimensions alternate along the length; corrugated; and circular. ; those with enlarged ends or hooks, etc.

2. The mixing principle of steel fiber concrete is dry mixing first and then wet mixing. The mixing process is as follows:

A. First put the steel fiber and aggregate into the mixer and dry mix for 0.5-1 minute to make the steel fiber evenly distributed in the aggregate;

B. Add cement and dry mix

C. Lift the sand, gravel, steel fiber and cement in the hopper into the mixing table and mix. Dry mix for 2 minutes first, then add water and mix for 2 minutes.

D. Place the evenly mixed steel fiber concrete into the carriage and transport it

E. Watering and spreading should be done tightly and evenly.

3.The advantages of steel fiber concrete are as follows:

A. Improve impact resistance

B. Improve earthquake resistance and durability.

C. Reduce the brittleness of concrete and increase toughness

D. Increase the bending, shear, fatigue strength and impact resistance of concrete

E. Adhesive steel fibers are evenly distributed and easy to mix

F. Compared with conventional concrete, the cost is reduced due to the reduced concrete thickness.

G is more economical and faster because it is simple and easy to do.

4. Comparison of performance using steel fiber and ordinary concrete: