This briefly introduces the application and characteristics of unbonded 15.2 steel strand in the construction process of prestressed concrete structures.

　　For unbonded prestressed 15.2 steel strand, a layer of lubricant and plastic sheath is applied to the steel strand. Unbonded steel strand impacting concrete is called unbonded steel strand because the outer layer of grease and sheath separates the 15.2 steel strand from the concrete, allowing it to move freely and bond with the concrete in an unbonded state. In civil engineering projects with large static loads, large-span factories or high-rise buildings are usually used.

　　Unbonded 15.2 steel strand has the characteristics of fast construction speed, reduced beam and slab thickness, improved structural performance, and economic benefits. The key to slow-bonded prestressed 15.2 steel strand is the slow-setting adhesive, which includes prestressed steel strand and sheath. Unbonded prestressing technology has many advantages. A bonding layer that solidifies after a certain period of time is filled between the prestressed steel strand and the sheath, and the outer surface of the sheath is covered with bamboo joints. During the reinforcement arrangement and tensioning stages, the prestressed steel bars and protective sheaths can slide, and the joint arrangement is sensitive. Due to the slow glue's corrosion resistance, it is particularly suitable for environments with chlorides or other corrosive media.

　　In recent years, the development of prestressed 15.2 steel strand has been very rapid, and its application range has become increasingly wider. At the end of the last century, China's annual output value had reached hundreds of thousands of tons. So far, its output value has reached millions of tons. It is believed that the application range and quantity of prestressed steel strand will continue to increase in the future.

　　Users have many product requirements for the use of 15.2 steel strand, but under the production of different manufacturers, some products can meet the requirements of users in all aspects, some can only meet part of them, and some cannot meet the requirements of one aspect. Therefore, attention should be paid when purchasing this product. So, what requirements should be met when using this product? One is the requirement for tensile force, which is also a basic requirement. However, some manufacturers do not have this performance because they are not good enough in production, materials, or processes.

　　In addition, what kind of flexibility does the steel strand have when used, because when using this product, or in different industries, or in more cases, it is hoped that it can achieve its due flexibility. Of course, whether our products have flexibility depends on the manufacturer's use of materials. For some small manufacturers, their materials will decline, so in this case, they cannot achieve their due flexibility advantages.

　　Therefore, as far as the flexibility of 15.2 steel strand is concerned, there are also user requirements, that is, what anti-corrosion measures the product has during use. Generally speaking, such products should achieve anti-corrosion effects, especially products used in complex environments. This is also an important prerequisite for them to be able to have anti-corrosion performance for their products. Of course, whether the product can be anti-corrosive depends on the materials used. Some non-corrosive materials are inexpensive. Small manufacturers like to use them, but they do not have anti-corrosion functions.