机械磨细对新疆和田地区火山岩粉活性影响试验  

Experimental study on effect of machine grinding in activity of volcanic rock fine in Hotan area of Xinjiang

作　　者：王怀义 杨桂权 李鑫 贺传卿 WANG Huaiyi;YANG Guiquan;LI Xin;HE Chuanqing(Xinjiang Institute of Water Resources and Hydropower Research,Urumqi 830049,China;Xinjiang Water Conservancy and Hydropower Material Engineering Technology Research Center,Urumqi 830049,China)

机构地区：[1]新疆水利水电科学研究院,新疆乌鲁木齐830049 [2]新疆水利水电材料工程技术研究中心,新疆乌鲁木齐830049

出　　处：《河海大学学报（自然科学版）》2020年第4期334-339,共6页Journal of Hohai University(Natural Sciences)

基　　金：新疆自然科学基金面上项目(2019D01A74)。

摘　　要：为了提高新疆和田地区火山岩粉的活性,拓宽其在混凝土工程中的应用,借鉴目前常用的机械磨细的球磨方法,使粉体材料更加细化,并改善其颗粒分布。对4种细度的火山岩粉,采用勃氏法测试其比表面积,激光粒度法分析其颗粒级配及分布,多龄期胶砂强度指数法去验证掺加该火山岩粉后的胶凝体系宏观力学性能变化,最后用SEM及EDS观察分析微观形貌及产物,揭示微观变化与宏观强度,即火山灰活性提升的关系。试验结果表明:机械磨细的方法可以有效地改善火山岩粉的颗粒分布,比表面积每增加80 m^2/kg左右则小于50%通过率颗粒粒径减小0.6~0.8μm;掺火山岩粉胶凝体系随龄期的延长,宏观上其抗折强度和抗压强度均有持续的提高,而且抗折强度增加速率更快,但强度增加随火山岩粉变细而增长的幅度放缓。根据宏观力学性能的变化及SEM及EDS的微观观察分析,得出结论:机械磨细可提高火山岩粉活性的主要原因为颗粒变细的"微集料"填充作用,以及其参与水泥基体系水化反应能力的提升。To improve the activity of volcanic rock powder in Hotan area of Xinjiang so as to expand its application to concrete works,this study adopted a commonly used machine grinding method,called the ball-milling method,to refine powder materials and improve their particle distribution.For volcanic rock powders of four sizes,this study investigated the specific surface area with the Blaine method,analyzed the particle grading and distribution with the laser particle size method,verified the change of macro-mechanical properties after the addition of volcanic rock powder with multi-age mortar strength index method,and analyzed the micro morphology and products with SEM and EDS,to reveal the micro change,the macro strength,and the relationship of activity improvement of volcanic ash.The test results show that the machine grinding method can effectively improve the particle distribution of volcanic rock powder,that is to say,the particle size with the passing rate of less than 50%will be reduced by 0.6-0.8μm when the specific surface area is increased by about 80 m^2/kg.With the increasing of age,the bending strength and compressive strength of cementitious system added with volcanic rock powder can be continuously improved on a macro level and the increasing rate of bending strength is faster.However,the strength increasing rate is slowed down with fining volcanic rock powder.Through the change of above macro-mechanical properties,the micro observation and analysis with SEM and EDS,the main reason that machine grinding can improve the activity of volcanic rock powder is the filling effects of micro aggregates from refined particles and the improvement of its hydration reaction capacity after addition with the cement-based system.

关 键 词：火山岩 机械磨细 颗粒分布 微观形貌 能谱分析 火山灰活性 微集料作用 新疆和田地区 

分 类 号：TU521.21[建筑科学—建筑技术科学]