6.砂率。在满足工作性要求的前提下，应采用较小的砂率。但最大不得超过4

6.砂率。在满足工作性要求的前提下，应采用较小的砂率。但最大不得超过42%。<br>7.配合比设计人员应深入施工现场，依据施工现场的浇捣工艺、操作水平、构件截面等情况，合理选择好混凝土的设计坍落度，针对现场的砂、石原材料质量情况及时调整施工配合比。

6. Sand ratio. On the premise of meeting the workability requirements, a small sand ratio shall be adopted. However, the maximum shall not exceed 42%.<br>7. The mix proportion designer shall go deep into the construction site, reasonably select the design slump of concrete according to the pouring and tamping process, operation level and component section at the construction site, and timely adjust the construction mix proportion according to the quality of sand and stone raw materials at the site.

6. Sand ratio. On the premise of meeting the workability requirements, a smaller sand ratio should be adopted. But the maximum shall not exceed 42%. 7. The mixture ratio designer should go deep into the construction site, reasonably select the design slump of concrete according to the casting technology, operation level and component section of the construction site, and timely adjust the construction mixture ratio according to the quality of sand and stone raw materials on the site.