【摘要】 对北京某砂石场的粗集料研究表明，当单位碱含量达６．０ｋｇ／ｍ３时，砼抗压强度降低１０～２０ＭＰａ；碱含量为９．０ｋｇ／ｍ３时，抗压强度降低２５ＭＰａ左右．微观分析表明．上述砼试件中，部分粗集料内部和边界存在碱－集料反应特征．更多还原

【Abstract】 Study on the coarse asgregate from a sandpit, Beijing shows that compressive strength of concrete containing the agsregate was decreased 10 to 20 MPa when unit alkali content of concrete was 6. 0kg/m3. And the strength was decreased 25 MPa when unitalkali Content was 9. 0/m3. Micro-analysis illustrates there existed the characteristics of alkali-aggregate reaction inner aggreggate and in the edge of the aggregate of above concrete specimeus更多还原