【摘要】 采用岩相法和快速砂浆棒法对长沙地区湘江的湘阴段、望城段和湘潭段3个河段砂卵石的碱活性进行了试验研究。岩相分析的结果表明:这3个河段的砂卵石的矿物组成没有明显差异,卵石主要由硅质石英岩和杂砂岩组成,砂主要由石英、长石、云母和杂砂岩组成,卵石和砂中的杂砂岩均含有一定量的隐晶石英和微晶石英。快速砂浆棒法测试的结果表明:这3个河段的砂卵石均具有碱活性。研究了粉煤灰和矿粉对卵石和砂碱–骨料反应膨胀的抑制效果,并首次使用正交设计法研究,得到了水泥–粉煤灰–矿粉三元胶凝体系中安全的胶凝组分区域。更多还原

【Abstract】 The alkali reactivity of sands and gravels from Wangcheng,Xiangtan and Xiangyin segments in Xiangjiang River was examined by means of a petrographic method and an accelerated mortar bar testing method.Petrographic analysis indicates that there is no much difference in mineral composition among these sands and gravels.The gravels consist predominately of siliceous quartzite and greywacke,while the sands are mainly composed of quartz,feldspar,mica,and greywacke.The greywacke in both sands and gravels contains a certain amount of cryptocrystalline and microcrystalline quartz.Accelerated mortar bar testing results show that the sands and gravels both have alkaline activity.Fly ash and slag powder were used for alkali–aggregate reaction inhibitation.In addition,a factorial design method was used to design safety compositions in portland cement–fly ash–slag powder ternary cementi-tious system.更多还原