南水北调中线工程漕河段岭东料场骨料碱活性研究

详细介绍了南水北调中线京石段应急供水工程漕河段岭东料场天然砂砾石骨料碱-硅酸反应活性的研究结果.岩相法检测显示卵石样品主要由石英、钠长石及白云石和少量云母类矿物组成,砂样品主要由石英、钠长石等矿物组成,重要的碱活性物质玉髓主要出现在白云岩裂隙和硅质灰岩的基质中;"砂浆棒快速法"检测结果显示砂、小石、中石样品14 d的膨胀率均不超过0.1%,为非碱-硅酸反应活性骨料,但卵石样品仍具有一定的碱活性,且后期膨胀率一直持续增长.综合"岩相法"和"砂浆棒快速法"的试验结果,认为漕河岭东料场的砂砾石骨料在工程中使用时必须采取有效的抑制措施.碱-硅酸反应抑制试验结果表明在混凝土中掺加20%～25%的粉煤灰抑制碱-硅酸反应是有效的.岭东料场的白云岩为不具有潜在碱-碳酸盐反应活性骨料.研究结果为漕河工程的料场选定及混凝土的配制提供了技术支持,为保证工程质量奠定了基础.

Research on Alkali Reaction of Aggregate Produced by Lingdong Stockyard

This article presents on ASR results of natural sand and gravel samples produced by Lingdong stockyard which supplying aggregates for construction of Caohe Project in the Middle Route Project for South-to-North Water Transfer. On petrographic facies test, gravel sample mainly consists of quartz,albite,dolomite,and minor biotite; and sand sample is mainly made up of quartz and albite; and as an important ASR active mineral,chalcedony contains in fractures of dolomite and exists in matrix of cherty limestone. In rapid mortar bar test, expansivities of sand, small gravel and middle gravel at 14 day are less than 0. 1 %, but keep increasing in long term. Synthesized previous results, the natural sand and gravel samples should be treat as ASR active aggregates,and effectively inhibitive measures MUST applied. Mixing 20%-25% fly ash in cement could effectively inhibit ASR of the aggregates, Dolomite in the aggregates is not active in ACR test.