sand n. 1.沙。 2.〔 pl. 〕 沙滩,沙洲,沙地,沙漠。 3.〔 pl. 〕 沙粒;(计时用的沙漏中的)细沙。 4.光阴,时间,寿命。 5.〔美俚〕勇气,毅力,胆量,坚毅。 6.【医学】砂状结石。 7.【地质学;地理学】含石油砂层。 8.粗矿石;尾矿;【冶金】模砂。 9. 砂色;带红的黄色。 10.〔美俚〕砂糖。 quick sand 流沙。 play on the sands 在沙滩上玩耍。 The sands [His sands] are running out. 期限快到[他的命数将尽]。 a man with plenty of sand in him 坚毅的人,刚强的人。 built on sand 不稳固的;不安定的。 footprints on the sands of time 留在人世变迁的沙滩上的脚印。 have sand in one's craw 〔美口〕有勇气[决断,毅力]。 knock the sand from under 〔美国〕使失去立足之地;(设法)占上风。 make ropes of sand 用沙结绳;做不可能[徒劳无功]的事。 numberless as the sand(s) 多如恒河沙数。 number [plough, sow] the sands 白费气力,徒劳。 put sand in the wheels [machine] 捣乱,暗中破坏。 vt. 1.撒沙于,铺沙于,把…埋进沙里,用沙搀入。 2.用沙[砂纸]擦[磨光]。 3.使(船)开上沙滩。 sand up 用沙填塞(油井等)。
In this paper , the so preparing self - compacting concrete with low and middle strength using super fine mountain sand artifical sand and phosphorus slag is studied systemically . through the study the influence of the shape , the proportion of the dust and the grade of sand to the workability and the mechanical property of self - compacting concrete , it is found that super fine mountain sand artifical sand are not suit to prepare low and middle strength self - compacting concrete , but when they are combined and the additive and assistant band material are used , c20 - c40 high performance self - compacting concrete is prepared ; the corresponding additive is developed to solve the delamination caused by the low proportion of banding material ; the evaluating system for the workability of low and middle strength self - compacting concrete is built ; the controlling method for production , construction and curing was set up . and the result of the research is applied into several projects 通过分析特细山砂和机制砂的颗粒形态、粉末含量、颗粒级配等特性对自密实混凝土的工作性能和力学性能的影响,发现特细山砂、机制砂不宜单独用于配制中低强度等级自密实混凝土,宜将特细山砂和机制砂进行合理复配,并选择合适的外加剂和矿物掺合料,优化配合比设计,可生产c20 c40中低强度等级自密实高性能混凝土;研制开发出了具有高效减水、保塑、抗离析功能的外加剂,有效解决了中低强度等级自密实混凝土由于胶凝材料用量少而出现的离析、泌水问题;应用正交设计方法,对因素和水平进行合理选择,确定了生产中低等级自密实混凝土的最优配合比;建立了中低强度等级自密实混凝土的工作性评价体系;提出了生产、施工及养护的质量控制技术方法。