黔东南地区变质岩骨料的碱活性及预防措施

Alkali Reactivity of Metamorphic Rock Aggregate and Its Prevention Measures in the Southeast Area of Guizhou Province

摘要:

选取黔东南不同地区的典型变质岩,研究其骨料的基本物理力学性能;采用岩相分析法、快速蒸养法、砂浆长度法等研究了其碱活性特征.结果表明,黔东南地区变质岩骨料的针片状、石粉含量较高,细度模数较大.变质岩骨料因含一定微晶石英成分而具有潜在碱硅酸活性,属慢膨胀型活性骨料.快速蒸养法与砂浆长度法对该地区变质岩骨料的碱活性判定结果存在明显差异,应采用2种试验方法对其碱活性进行综合评定.针对该地区变质岩骨料的碱活性特征,从碱活性判定方法、混凝土总碱量、大掺量粉煤灰、石粉含量、混凝土应用环境等方面提出了变质岩碱骨料反应预防措施.

Abstract:

Physical and mechanical properties of typical metamorphic rock aggregates selected from different places in the southeast area of Guizhou province were studied,and their alkali reactivity characteristics was studied using test methods such as petrographic analysis,rapid steam curing method and mortar-bar method.The results indicate that physical properties of these metamorphic rock aggregates are as follows: high content of needle and plate-like particles and rock powder,and high fineness modulus.Metamorphi...