First, the definition of stranded steel strand is composed of multiple steel wire stranded steel products, carbon steel surface can be increased according to the need for galvanized layer, zinc-aluminum alloy layer, aluminum cladding, copper-plated layer, coated with epoxy resin and so on.
Second, the classification of steel strand according to the use of classification: prestressing strand, (power) galvanized steel strand and stainless steel strand, which prestressing strand coated with anticorrosive grease or paraffin wax wrapped in HDPE is called non-bonding prestressing strand, prestressing strand is also galvanized or zinc-alloyed aluminum alloy steel wire made. Classification according to material properties: steel strand, aluminum clad steel strand and stainless steel strand. Classification according to structure: prestressing steel strand can be divided into 7 wires, 2 wires, 3 wires and 19 wires according to the number of wires, commonly used is 7 wires structure. Galvanized steel strand and aluminum-coated steel strand for electric power are also divided into 2, 3, 7, 19, 37 and other structures according to the number of wires, commonly used is the 7-wire structure. According to the surface coating layer classification: can be divided into (glossy) steel strand, galvanized steel strand, coated with epoxy strand, aluminum-clad steel strand, copper-plated steel strand, plastic-coated steel strand and so on.
Third, the application of steel strand galvanized steel strand usually refers to be used for load-bearing cable, pulling line, reinforcing core, etc., can also be used as the ground line of overhead power transmission, highway on both sides of the blocking cable or building structure in the structure of the cable. Prestressing strand commonly used in prestressing strand for the uncoated low relaxation prestressing strand, there are also galvanized, commonly used in bridges, construction, water conservancy, energy and geotechnical engineering, etc. Unbonded prestressing strand is commonly used in floor slabs, foundation projects, etc..
Fourth, the detection of steel strand strand and its connectors is an essential material for construction projects, steel strand and its connectors test is directly related to the quality of construction projects and safety issues, so it is very necessary to test the steel strand. The test items of steel strand include tensile test, external dimensions, strand straightness, relaxation rate, modulus of elasticity and so on.