The adaptability of concrete drainage pipe forming and pipe making technology for concrete water conveyance pipe?

Adaptability of Forming and Manufacturing Technology of Reinforced Concrete Drainage Pipe for Concrete Pipeline

The manufacture and use of reinforced concrete drainage pipe has been more than one hundred years in China. The original method of making pipes was simple manual vibration stamping, and only small-caliber flat-caliber pipes could be produced.

Since the founding of the People's Republic of China, with the rapid development of the national economy, the demand for the use of drainage pipes has become higher and higher, and the production technology level has been constantly improved.

At present, the variety of drainage pipes is no longer a single flat pipe. Various products with flexible interfaces such as entrance pipes, socket pipes and steel socket electric pipes have been widely used in drainage, sewage and other projects such as power cables in urban and rural construction in China. The use of special-shaped pipes, pipes with base, electric trench pipes and anticorrosive pipes with higher technology is becoming more and more common. 。 The launching of the special national plan for urban sewerage projects requires the laying of urban pipeline corridors, which will surely promote a new round of development in the production and application of drainage pipes.

Drainage pipe product specifications from small to large, 4000mm diameter pipe jacking products have been successfully used in construction projects, indicating that China's drainage pipe production and use level has reached the international advanced level.

What are the factors affecting the corrosion of reinforced concrete pipes and plastic pipes? The main factors affecting corrosion are as follows:

1. pH value of water. Iron bacteria and sulfate reducing bacteria in pipeline are suitable to live in neutral and acidic medium. When the pH is 8.0, their growth is inhibited, and when the pH is above 8.4, they hardly grow. The results showed that iron bacteria grew in the range of pH 5.96-7.89 and sulfate reducing bacteria grew in the range of pH 5.96-8.35. Furthermore, Fe (OH) is the main product of corrosion. It can dissolve in acidic medium, but not in alkaline medium. Therefore, acidic water with low pH value can promote corrosion and high pH value can prevent or completely stop corrosion.

2. The existence of corrosive carbon dioxide. If there is no corrosive carbon dioxide, the reaction first produces ferrous hydroxide, then oxidized by dissolved oxygen in water to form ferric hydroxide, forming passive protective film, which slows down the corrosion rate of pipe wall. Otherwise, after the formation of ferrous hydroxide, it reacts with carbon dioxide to form ferrous bicarbonate, which is soluble and loses in water. It is oxidized by dissolved oxygen in water to form ferrous hydroxide, and red water appears, some of which dehydrates to form rust. Therefore, the existence of corrosive carbon dioxide will aggravate the corrosion of pipelines.

3. The velocity of water. With the increase of water flow rate, oxygen supply is easy, which promotes pipeline corrosion. When the flow rate increases, the oxygen supply increases, and the surface of iron pipe tends to be passivated due to excess oxygen, which reduces the corrosion. Concrete Pipeline