Is mainly the size effect and solidification, shrinkage, stress and other issues clearly, to avoid or reduce the segregation, iron manhole cover deformation and crack defects.
The quantity and the thickness of commodity concrete is more than normal concrete, which tends to occur shrinkagecrack in structure when transporting or pumping.
商品砼为满足运输或泵送的流动性要求，一般水泥用量较多，砼的稠度较大，容易引起收缩裂缝的出现。
3
Temperature and shrinkagecrack of huge concrete can destruct concrete structure, so it is important to control the crack.