白云石制备矿物掺和料及对混凝土性能的影响  

Preparation of Concrete Admixtures with Dolomite Rock Debris and Its Influence on Concrete Properties

作　　者：贾丽莉[1] 高育欣[1] 赵日煦[1] 彭园[1] 杨龙[1] 霍亮[2] 

机构地区：[1]中建商品混凝土有限公司,湖北武汉430074 [2]中国建筑工程总公司技术中心,北京101300

出　　处：《施工技术》2015年第3期61-65,共5页Construction Technology

摘　　要：试验将白云石岩屑磨细为粉体,用作混凝土掺和料,研究其易磨性、活性、碱-白云石活性及对混凝土力学性能和工作性能的影响。结果表明:白云石岩屑较水渣易粉磨,水渣粉磨4min时,平均粒径为18.01μm,白云石屑粉磨2min平均粒径即为4.28μm,而继续粉磨细度增长缓慢,且易结团黏聚;单独磨细白云石粉的活性低于62%,低于II级粉煤灰,而采用水渣与白云石共磨,使共磨复合掺和料的28d活性达到75%以上,较单独的白云石粉活性提高18%;在Na OH溶液中养护14d的基准试件及掺白云石粉试件膨胀率均低于0.1%,依据标准白云石粉作为掺和料不具有ACR活性危害;单掺白云石粉使混凝土早期和后期强度均降低,而白云石-水渣复合掺和料使混凝土早期强度略有增长。The fine grinding of dolomite rock debris was used as concrete admixture. This paper studies on its grindability, active effects, alkali？dolomite reaction effects, and its impact on the mechanical properties and working performance of concrete. The results showed that the dolomite rock debris was easy to grind than slag, the average particle size of slag grinding for 4min is 18？01μm, whereas, the average particle size is 4.28μm for dolomite rock debris grinding only 2min, and the prolonged grinding make little growth in fineness and prone to particle aggregation. The activity of ground dolomite powder is less than 62%, lower than FA II. By grinding the dolomite with slag together, the activity of dolomite composite admixture is more than 75%, increased by 18% compared to separate dolomite activity. The expansion of both reference samples and dolomite admixture samples is less than 0.1%, curing for 14 days in NaOH solution, thus the grinding dolomite powder as mineral admixture has no active harm of ACR according to the standard. Single added with dolomite power reduced early and later strength of concrete, however, the dolomite composite admixture improved the early strength of concrete.

关 键 词：混凝土 白云石粉 掺和料 活性 强度 

分 类 号：TU528.0[建筑科学—建筑技术科学]