What is the production process of concrete drainage pipes?

Concrete drainage pipe is a kind of prefabricated component widely used in municipal engineering, water conservancy engineering, construction engineering and other fields. It is mainly used for drainage, sewage discharge, irrigation and other purposes. Its production process is a systematic process, involving raw material preparation, mold assembly, concrete mixing, molding, curing, demoulding, inspection and other links. The production process of concrete drainage pipes will be introduced in detail below.

1. Raw material preparation

The main raw materials for concrete drainage pipes include cement, sand, gravel, steel bars and water. The quality of these raw materials directly affects the strength, durability and performance of the drain pipe.

Cement: Ordinary Portland cement is usually used, and its label is selected according to the design requirements. The commonly used ones are P.O42.5 or P.O52.5.

Sand: Use medium-coarse sand, and the mud content must be controlled within the specified range to ensure the workability and strength of the concrete.

Stone: Generally, crushed stone with a particle size of 520 mm is used, which is required to be hard, non-weathered, and free of impurities.

Rebar: used to enhance the tensile strength of concrete drainage pipes, usually using HRB400 or HRB500 grade threaded steel bars.

Water: Water quality should meet the standards for concrete mixing water and should not contain harmful substances such as oil, acid and alkali.

2.Mold assembly

The mold is the key equipment for forming concrete drainage pipes, and the finish of its inner wall directly affects the surface quality of the pipe. The mold is usually made of steel mold or composite material and is divided into two parts: inner mold and outer mold.

Clean the mold: Before each use, the mold needs to be thoroughly cleaned to remove residual concrete and debris, and a release agent should be applied to facilitate subsequent demoulding.

Assemble the mold: Assemble the inner mold and the outer mold according to the design requirements to ensure that the size and shape of the mold are accurate. The joints of the mold must be tight to prevent concrete from leaking.

3. Concrete mixing

Mixing of concrete is an important part of ensuring the quality of drainage pipes. The mixing process must be carried out strictly in accordance with the mix ratio to ensure the uniformity and workability of the concrete.

Ingredients: Accurately weigh cement, sand, gravel, water and other raw materials according to the designed mix ratio.

Mixing: Put the raw materials into the mixer, and the mixing time is generally 23 minutes until the concrete is uniform and consistent without obvious particles and bubbles.

4. Forming

The forming processes of concrete drainage pipes mainly include centrifugal forming, suspension roller forming and vertical vibration forming. Different molding processes are suitable for drainage pipes with different specifications and requirements.

Centrifugal molding: Pour the mixed concrete into a rotating mold, and use centrifugal force to evenly distribute the concrete on the inner wall of the mold while draining excess moisture and air bubbles. Centrifugal forming is suitable for small and medium diameter drainage pipes.

Suspended roller forming: After pouring the concrete into the mold, the concrete is densely formed through the extrusion and vibration of the suspended roller. Suspension roll forming is suitable for large diameter drainage pipes.

Vertical vibration molding: Pour concrete into a vertical mold, and use a vibrator to compactly shape the concrete. Vertical vibration forming is suitable for drain pipes of special shapes or sizes.

5. Maintenance

After the concrete drain pipe is formed, it needs to be cured to improve its strength and durability. There are two main maintenance methods: natural maintenance and steam maintenance.

Natural maintenance: Place the formed drainage pipe in the open air or indoors to maintain a certain humidity and temperature. The curing time is generally 714 days.

Steam curing: Put the formed drainage pipe into a steam curing room, and use high-temperature steam to accelerate the hydration reaction of the concrete, and the curing time can be shortened to 1224 hours.

6. Demold

After the curing is completed, the drain pipe needs to be removed from the mold. The demoulding process needs to be done with caution to avoid damaging the pipe.

Disassemble the mold: disassemble the outer mold first, then the inner mold, taking care to avoid impact or scratches on the pipe.

Clean the pipe: After demoulding, the surface of the pipe needs to be cleaned to remove residual release agent and concrete debris.

7.Inspection

After the production of concrete drainage pipes is completed, strict quality inspection is required to ensure that they meet the design requirements and relevant standards.

Appearance inspection: Check whether the surface of the pipe is flat and smooth, and whether there are any defects such as cracks, honeycombs, and pitted surfaces.

Dimensional inspection: measure the inner diameter, outer diameter, wall thickness and other dimensions of the pipe to ensure that it meets the design requirements.

Strength testing: Test the mechanical properties of the pipe through compression tests, bending tests, etc. to ensure that it meets the usage requirements.

Water tightness test: Conduct a water tightness test on the pipe to ensure there is no leakage.

8. Packaging and transportation

Inspected concrete drain pipes need to be packaged and shipped to prevent damage during transportation.

Packaging: Straw ropes, wooden frames and other materials are usually used to bundle the pipes to protect the surface of the pipes from damage.

Transportation: Handle with care during transportation to avoid collisions and bumps to ensure that the pipes arrive at the construction site intact.

Summarize

The production process of concrete drainage pipes is a complex and delicate process, involving the close cooperation of multiple links. From raw material preparation to final inspection, every link needs to be strictly controlled to ensure the quality and performance of drain pipes. Through scientific production management and strict quality control, high-strength and durable concrete drainage pipes can be produced to meet various engineering needs.