The Manufacturing Process of Concrete Pipes: 1. To minimize the likelihood of concrete collapse, mechanical crushing of stones is recommended. These stones have a rough surface, making the concrete easier to interlock, which is suitable for large-diameter suspended roller pipe machines. Alternatively, river pebbles or crushed stones are chosen to reduce friction between individual stones. 2. For dry, hard concrete, less cement is used, resulting in a lower cement dosage per unit. This usually prevents shrinkage cracks, contributing significantly to the stability and compactness of the concrete, preventing inner wall collapse, and enhancing steam curing. Therefore, it is suggested to opt for common silicate cement. 3. When selecting sand, avoid overly fine or coarse varieties, generally using medium sand.