1: Concrete pipes possess sufficient strength, excellent plasticity, and low hardness, which is one of the reasons for their widespread adoption. Similar to the majority of other metallic materials, the tensile strength, yield strength, and hardness of concrete pipes increase with decreasing temperatures; conversely, their plasticity decreases. More importantly, their impact toughness decreases slowly with decreasing temperatures, and there is no brittle transition temperature. Therefore, concrete pipes maintain adequate plasticity and toughness at low temperatures.

2: In general concrete products, an increased slag content is often used, which is also a significant factor affecting the corrosion resistance of cement pipes. At this point, more activators are needed to stimulate the cement pipe's latent hydration activity. The addition of anhydrite, which is produced through the hydration of clinker, is a key measure to enhance the water-cement properties. Increasing the anhydrite content can significantly improve the early and later strength of cement products.

At 10.5% cement addition, the cement pipe's resistance to atmospheric corrosion significantly improves. However, as the cement content increases, while the corrosion resistance can still be enhanced, the improvement is not pronounced. This is because when cement is used to alloy the cement pipe, the type of surface oxide is changed to a type similar to that formed on the surface of pure cement metal. This tightly adhered, cement-rich oxide protects the surface from further oxidation. This oxide layer is very thin, allowing the natural luster of the drainage pipe surface to be seen through it, giving the cement drainage pipe a unique surface. Moreover, if the surface is damaged, the exposed drainage pipe surface will react with the atmosphere to self-repair, reforming this "passivation film" of oxide and continuing to provide protection.