主要水平 meaning in English

sill

The author has done much research work in examining the functions of raw materials , as well as making graph analysis of the raw material . as a result , achievement have been made : ( 1 ) making sure of the standard factor and t he best mixture proportion , ( 2 ) finding out the best way of measuring the index of the high performance concrete , ( 3 ) the endurance of this high performance concrete and the volume stability have been experimented ; ( 4 ) the great economic and social benifit are obtained by cost analysis
其主要工作进行了各种原材料的性能检验并做出相应图表分析；对掺超细矿渣粉末的高性能混凝土进行正交试验，确定了主要水平因子和最佳配合比；通过对高性能混凝土的耐久性试验及高性能混凝土的体积稳定性试验，确定检测高性能混凝土耐久性指标的最佳方法及高性能混凝土的热胀冷缩率和体积稳定性；通过对高性能混凝土的成本分析，确定掺超细矿渣粉的高性能混凝土其经济效益和社会效益非常显著。