The construction technology of steel fiber in construction and use also has certain requirements. Steel fiber refers to the fiber whose growth diameter ratio (the ratio of fiber length to its diameter, when the fiber cross-section is non-circular, the diameter of equivalent cross-section circular area is converted) is 40-80 by cutting thin steel wire, cutting cold-rolled strip, milling ingot or rapid condensation of molten steel. In order to make the steel fiber more evenly dispersed in mortar or concrete and increase the length diameter ratio of fiber, steel fiber with water-soluble adhesive can be used to form bundles. Steel fiber can be made by cutting cold drawn steel wire, cutting thin steel plate, milling steel block or ingot, and drawing yarn of molten steel. We have already talked about the key problem of steel fiber mixing. Now we will mainly talk about the seven requirements from the external factors
1. It is possible to participate in the consistent steel fiber concrete of the same project to determine the required consistency of ordinary concrete. This slump value is 20 mm smaller than the corresponding ordinary concrete, in which the Weibo consistency value and the same corresponding value of ordinary concrete are required.
2. The cement grade shall not be less than 425, and the cement ratio shall not be greater than 0.5
3. The content of steel fiber in steel fiber reinforced concrete should not be less than 0.5%, and the selection range should be controlled within 0.5 or 2%.
4. Other materials used in steel fiber reinforced concrete shall comply with the provisions of the current code on raw materials of reinforced concrete
As shown in Figure 5, the path length of the particles should not exceed 2 / 3 of the length of the skeleton steel fiber.
6。 When the steel fiber reinforced concrete layer and the surface course of flat joint structure are not paved with lime soil under the cushion, and meet the following conditions: the thickness of cushion and surface layer before removal is not less than 130cm; the thickness of foundation reinforcement layer is greater than that of cushion layer, and the thickness can be 0.75, but not less than 50cm.
When mixing steel fiber concrete, it is not allowed to use sea water, sea sand and chlorine salt.
