The Performance Advantage of Steel Fiber Reinforced Concrete

1. The strong impact resistance of steel fiber reinforced concrete

Under the action of dynamic load, when the cracks propagate in the steel fiber reinforced concrete, the steel fiber is first pulled out by overcoming the bonding force of the base material, or the steel fibre reaches the yield strength and is broken. This requires a lot of energy. Therefore, steel fiber reinforced concrete can improve the impact resistance. If the grade of steel fibre reinforced concrete is CF55, the hardened cement is used to test the heavy impact of the concrete. 

If the mixing quantity of steel fibre is 0.5%, the number of impact resistance is 3~4 times that of plain concrete; if the mixing quantity of steel fibre is 1%, the number of impact resistance is 11~12 times; if the mixing quantity of steel fibre is 1.5%, the number of impact resistance is 21~22 times. It can be seen that the impact resistance of steel fibre reinforced concrete is greatly improved with the increase of the mixing quantity of steel fibre such as glued steel fiber.

2. Superior fatigue resistance of steel fiber reinforced concrete

Steel fiber obviously improves the bending fatigue performance of concrete. If CF80 steel fibre reinforced concrete is compared with ordinary concrete, when the mixing quantity of steel fiber is 1%, the fatigue limit of 2 million cycles can be increased by 10%; when the mixing quantity of steel fiber is 1.5%, the fatigue limit can be increased by 15%. When the fatigue stress ratio is 0.7, the fatigue life of steel fiber reinforced concrete with 1% steel fiber mixing quantity can be prolonged.

3. Freeze-thaw resistance of steel fiber reinforced concrete

During the freeze-thaw cycle of steel fibre reinforced concrete, due to temperature changes, a thermal stress field is formed in the reinforced concrete. Because of the different thermal expansion coefficients of the steel fiber reinforced concrete matrix components, the deformation and dissonance of the components appear under the action of temperature stress, resulting in tensile stress in the internal interface of the reinforced concrete, which affects the bonding behavior of the interface. The increase of the volume ratio of steel fiber increases the interface in the reinforced concrete, which is the weak link of the concrete. When the number of freeze-thaw cycle is not large, and the bonding properties of the steel fibre and the mortar are good, the steel fiber can effectively play the role of crack resistance and reinforcement, reducing the number of crack sources and the width of cracks. Therefore, when the number of freeze-thaw cycle is small, with the increase of the volume rate of steel fiber, the decrease in the reinforced concrete strength decreases.