grading limit meaning in English

级配范围
粒度范围
粒级界限

Because the best grade limits does not vary with material property , firstly , we can confine material grade to the best grade limits when doing subbase mixture design , secondly , after systematic temperature contraction test , aridity contraction test and compressive strength correction test , we can determine the best cement percentage which has the best crack resistance property
因为最佳级配范围是与粒料的粒径大小有关的，所以在基层材料配合比设计时可首先将材料级配限制在最佳级配范围以内，然后通过系统的温缩、干缩性能试验以及抗压强度校核试验，最终确定抗裂性较好的合理水泥剂量。
We must take account of crack resistance when doing mixture design . after systematic and scientific determination and analysis of temperature contraction property , aridity contraction property and strength index , the thesis have chosen the best grade limits in which crack resistance and compressive strength are high . this conclusion is based upon standard ? grade limits of cement stabilizing crushed stones subbase
本课题在对水泥稳定类材料温缩、干缩性能以及强度和模量等指标的测试分析前提下，以规范原有的水泥稳定碎石基层级配范围为基础，选择出抗裂性和抗压强度两项指标俱佳的级配范围。