2015年2月上第44卷第3期
DOI:10.7672/sgjs2015030061
施工技术
CONSTRUCTIONTECHNOLOGY
白云石制备矿物掺和料及对混凝土性能的影响
贾丽莉，高育欣，赵日照'，彭园杨龙，霍亮？
（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）
【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Na0H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。
【关键词］】混凝土；白云石粉；掺和料；活性；强度
【中图分类号］TU528.0
【文献标识码］】A
【文章编号】1002-8498（2015)03-0061-05
PreparationofConcreteAdmixtureswithDolomiteRockDebris
andItsInfluence on Concrete Properties
Jia Lili', Gao Yuxin', Zhao Rixu',Peng Yuan', Yang Long',Huo Liang(1. China Construction Ready Mixed Concrete Co., Lid., Wuhan, Hubei 430074, China;
2.China State Construction Technical Center, Bejing101300, China)
Abstract: 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. 28 μm 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 I. 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. Key words : concrete; dolomite power; admixtures; active effects; mechanical strength
引言 0
我国的石灰石、白云岩等矿产资源丰富，现已探明储量40亿t以上，其远景储量巨大。每年白云石开采量超过千万t，平均每t矿石约产生0.15~ 0.20t石屑。石屑粒径一般<5mm，大部分多棱角状或片状，且其莫氏硬度较低，并含有大量的石粉。
【作者简介］贾丽莉，技术研发员，助理工程师，E-mail:jiali608927@ 126.con
【收稿日期］2014-05-05
61
这种开采废屑的堆不仅占用土地而且易造成环境的污染[1-2]
目前，对白云石岩屑的研究和应用并不多，主要的研究方向是将白云石碎屑用作细骨料运用于混凝土的配制，宝钢炼钢厂研制了白云石碎屑配制混凝土并通过鉴定，河海大学的蒋林华等人也进行了白云石石屑混凝土试验研究，卢都友、李爱美和唐明述等人也研究了泥质白云质灰岩为骨料的岩石试块的膨胀性能研究[16]。研究发现，白云石试