The surface of prestressed steel strand is covered with lubricant, oil stain, etc., which is the material to reduce the adhesion between steel strand and concrete. Fine rust can appear on the surface of the steel strand, but it cannot rust in the visible pockmarks. Now let's learn about the types of steel strand and its use!
The mechanical performance indexes of prestressed concrete steel strand are maximum load, elongation, yield load and slack rate. The experimental effect must conform to the regular numerical value.
The total tensile resistance of steel strand to steel of the same raw material and several small area wires can be greater than that of steel bars of the same area; Together, the steel bar is not easy to bend, and the steel thread is soft and easy to operate. The steel cable is more reasonable than steel, but it is loose and difficult to operate, so it is mostly used for super large load bearing cables. As the steel strand is more integrated with machinery, it is often used for the steel strand on the top of the prestressed project. Steel strand is a steel product composed of multiple steels. Galvanized layer, zinc aluminum alloy layer, aluminum cladding layer, copper coating, epoxy resin, etc. can be added on the carbon steel surface as required.
As for the concept of steel strand, it is called steel strand that multiple steel strands made of steel wires are mechanically twisted at one time according to the rules.
When the stranded wire is prestressed, the exposed part of the stranded wire is mostly wrapped by the anchor rod and jack, so the tension elongation of the stranded wire cannot be directly measured as the steel strand, and only the piston stroke of the tensioning jack can be measured to calculate the tension elongation of the stranded wire, but the bearing capacity of a steel strand must be 4-6 times of the total traction. Stress corrosion is caused by the action of tensile stress of steel and corrosion medium. In other words, the grains of the steel strand slip under the action of tensile stress. When there is corrosion medium, the materials between grains are destroyed, and then the steel cracks along the grain boundary and expands.
In many post tensioned and pre tensioned prestressed projects, smooth steel strand is the most widely used prestressed steel. The drawing of steel strand is mainly used for improvement projects, as well as atomic power generation projects. Chongqing steel strand is commonly used in the construction of bridge tie bars, cables and external prestressing. The use of epoxy coated steel strand is similar to that of galvanized prestressed steel strand.
Copyright ©2022 Huayi Changsheng All Rights Reserved. Technical support： Vamedia Star
