improving the anchorage force

Since the interfacial adhesion between steel fiber and concrete matrix is ​​primarily physical in nature, that is to pass friction shear, hence the steel fiber itself, it should be from the fiber surface and the fiber shape both to improve its bonding properties . There are four specific methods.
 
1) steel fiber surface roughening, irregular-shaped cross-section. Using melt pumping production can achieve this goal. Because the steel fibers in the case of air chilling time, the surface becomes rough and uneven shrinkage, but also shrink into a crescent-shaped cross-section, increasing the area of ​​contact with the substrate.
 
2) along the axial direction of steel fiber of the spaced fiber plastic working. For example, Japanese Kobe Steel's "letter Ke" Steel Fiber US Leibang company "XOREX" steel fiber (Figure 2-1, c) and Qing'an steel plant "S-2" and "S - 3" No. steel fibers. Since the surface is pressed into prismatic, or pressed into a wave, increasing the mechanical adhesion.
 
3) making different forms of both ends of the steel fibers. Bekaert company"DRAMⅨ" steel fiber (Figure 2-1, e) and Qing'an steel factory "S-4 'and as-so steel fibers, are made at both ends of the hook. There melt extraction method to extract the bulk of shaped steel fiber. Since both ends of the anchor role, improved pull-out resistance.
 
4.) epoxy coated on the surface of steel fiber and micro-rust treatment to the surface. This method to improve the interfacial bond strength is not as good as the above three methods, but also there is some enhancement.
 
Kobayashi, one auxiliary, University of Liege, Belgium, and Wen-face classes and other test proved hooked steel fiber reinforcing effect higher than the flat steel fiber and it is about double .the effect of the test described Kobayashi auxiliary pressure ridge has a curved steel fibers close Hook the steel fibers. These deformed steel fiber not only improves the strength of steel fiber but also improved toughness. Although corrugated steel fiber to improve the strength of steel fiber reinforced concrete plays a minor role, but can exponentially increase the toughness.