Forming method of cement pipe
There are methods of centrifugation, shaking, rolling, vacuum operation, and the combined effects of rolling, centrifuging, and shaking. In order to improve the performance of concrete pipes, China and many other countries have developed more prestressed concrete pressure pipes. This pipe is equipped with longitudinal and hoop prestressed steel bars, so it has a high ability to resist cracking and seepage. In the 1980s, China and some other countries launched self-stressed reinforced concrete pipes. The main feature is the use of self-stressed cement (see special cement) to pre-stress the swelling effect during the hardening process, which simplifies the manufacturing process. Compared with steel pipes, concrete pipes can save a lot of steel, extend the service life, and have less plant investment and convenient laying equipment. They have been widely used in factories, mines, oil fields, ports, urban construction and farmland water conservancy projects.
The socket cement pipe uses a rubber ring to seal the water stop. It is a flexible connection. The penetration depth of the interface is 80-100mm and the relative angle of the interface is 1.5 °. The cement pipe of the socket cement pipe has good seismic performance. The device is fast.
After the cement pipe is played, the cement pipe and the mold are placed in the open air for natural maintenance. Generally, after the cement pipe is played, it requires one day for open-air maintenance, and the mold can be opened the next day. For natural maintenance, a special person sprays water on the cement pipe three times a day.The time is usually once in the morning, once at noon, and once in the afternoon.The purpose of the water spray is to maintain the humidity of the cement pipe so that the concrete can gradually set itself, and the number of water sprays can also be based on Climate conditions and climate humidity add and reduce the number of water sprays.
First, steam culture method
The first is to build a steam curing pond.The general steam curing pond needs 2.5 meters wide, 4 meters long, and 3 meters deep.It can also be based on its own output and the size of the mold.It also requires a boiler to transport steam to the steam curing pond. The degree of tightness of the steam curing pond is better, and it can be used after the steam curing pond is completed. After the cement pipe is completed, it can be hoisted into the steam curing pond for steam curing. Generally, steam curing is required for 2.5--3.5 hours. Well, the higher the temperature, the shorter the time of steaming, the time of steaming is inversely proportional to the temperature of the steam. The higher the temperature, the better
Second, natural maintenance
Natural maintenance means that there is no need for a steam curing pond.After the cement pipe is played, the cement pipe and mold are placed in the open air for natural maintenance.Generally, after the cement pipe is played, it is required to perform open-air maintenance at the time of the day, and the mold can be opened the next day. Natural maintenance is also required for 4-6 days, and a special person sprays water three times a day on the cement pipe. The time is usually once in the morning, once at noon, and once in the afternoon. The purpose of the water spray is to maintain the humidity of the cement pipe so that the concrete can gradually grow by itself. The number of condensation and water sprays can also be added and reduced depending on the climate and humidity. However, there are many molds for natural maintenance.
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What are the installation construction techniques for reinforced concrete drainage pipes?
1.It is necessary to check the elevation of the slope board before the construction of the foundation, and to make the same pile every 4cm at the bottom of the trench, and use the sample pile to control the digging surface, cushion layer and root surface.
2.The sand cushion at the bottom of the pipeline should be paved, flattened and compacted according to the regular groove width.
3.When installing the lateral formwork of the concrete foundation on the sand cushion layer, the centerline should be pulled out on the inclined plate according to the center position of the pipeline, and the position of the direction finding template should be controlled by a vertical ball and a horse (the width and the concrete foundation). The horses are fixed at a distance of 2.5m to fix the formwork. The horses can be removed after the concrete is poured, and then they can be stored.
4.The direction-finding formwork for concrete roots should have a certain strength and rigidity. Generally, steel braces and steel molds can be used. The formwork device should have a gap of Yang Mi, strong support, and meet the requirements of the structural scale.
5.After the concrete base is poured, use a wooden wiping formwork or a flat plate oscillator to flatten it. Do not immerse in water for 12 hours, and maintenance should be performed. The mold can only be removed after the concrete strength reaches 2.5MPa.
6, when the flat foundation concrete is stronger than 5.0N / mm2 can be used for safety management, the use of cranes to lower the pipe during construction, and strictly follow the requirements of relevant regulations and standards. When the manual lower pipe, the same pipe should be the same command, consistent Signals, clear division of labor, harmonious hype, measures to prevent the tube from rolling should be adopted when stabilizing the tube. Hands and feet must not reach into the end and bottom of the tube. After the tube is stable, it is necessary to block the cover.