What is the difference between prestressed cement pipe and self-stressed cement pipe
The self-stressing cement has a large swelling rate and is often used to make self-stressing reinforced concrete pipes. Self-stressing cement is divided into silicate self-stressing cement, aluminate self-stressing cement and sulphoaluminate self-stressing cement. The commonly used Portland self-stressing cement is a swellable hydraulic cementitious material obtained by grinding ordinary Portland cement, high alumina cement and natural dihydrate gypsum with a strength ratio of 42.5 or more. Prestressed cement pipe is a bidirectional prestressed reinforced concrete pipe made by applying longitudinal and hoop stresses to the pipe body in advance. It has outstanding crack resistance and its resistance to soil current corrosion is much better than metal pipes. Today's cement pipe takes us to understand what is the difference between prestressed and self-stressed cement pipe!
What is prestressed concrete cement
Most of the large diameter and high pressure cement pressure pipes are prestressed reinforced concrete pipes. There are two types of flat mouth and socket. The flat mouth style has gradually been eliminated. The socket-type pipe is divided into a socket section, a pipe body and a socket section along the longitudinal entire length. Circumferential and longitudinal prestressed steel bars are arranged in the pipe wall. The inner diameter is as small as 10cm, and the large one can be several meters. The thickness of the pipe wall is determined by the diameter of the pipe and the internal pressure.
Generally, three-stage or one-stage pipe-making process is used for production. It has outstanding impermeability and crack resistance, strong conveying capacity and long service life. Used to replace steel pipes and cast iron pipes can save a lot of metal data. Used for water, oil, gas or other substances. Its defects are relatively large self-weight, brittleness, and easy breakage during transportation and installation.
In the pipe-making process, the reinforced concrete pipe that makes the concrete of the pipe body obtain the pre-stressing force is generally called the pre-stressed concrete pipe. It can accept higher radial pressure in the tube. Widely used in various pressure water pipelines, as well as oil and gas pipelines. Pipes with a diameter of less than 0.4 meters are small-diameter pipes, 0.4-1.4 meters are medium-diameter pipes, and those with more than 1.4 meters are large-diameter pipes. There are two types of pipe joints: socket type and flat type. The socket-type pipe is a flexible joint, which is convenient to install and has a good effect of sealing and stopping water.
The flat mouth pipe is simple to manufacture, but the sealing effect is poor, and the joint is easy to crack and leak. The production process of the tube is divided into three stages and one stage. The three-stage pipe making process firstly manufactures a concrete pipe core with prestressed or non-prestressed longitudinal steel bars, and then surrounds the prestressed steel wire on the pipe core, and then coats a layer of mortar protection on the outside of the wire. The one-stage pipe-making process is a combination of three processes into one process.
Prestressed reinforced concrete pipes can generally save about 70% of steel compared to steel pipes, and reduce the cost by about 60%, which has higher crack resistance and better impermeability than general reinforced concrete pipes. Countries around the world are actively promoting and expanding production, and are developing in the direction of large caliber and light and high intensity. The main defects of prestressed reinforced concrete pipes are brittleness and fear of collision. Prestressed reinforced concrete pipe can be used as a pressure water pipe, which can replace steel pipe and cast iron pipe, reducing the project cost. It is a common water pipe in small towns in China. In addition to the low cost of prestressed reinforced concrete pipes, the corrosion resistance is far better than metal pipes.