南水北调中线工程陶岔—沙河段混凝土碱骨料反应试验研究

Experimental Study on AAR from Taocha to Shahe along the Middle Route of South-to-North Water Diversion Project

南水北调中线工程陶岔—沙河段路线长,涉及料场多,骨料品种杂。碱—骨料反应具有反应缓慢、持续时间长的特点。碱—骨料反应十分复杂,需用不同的试验方法进行综合评定。通过岩相法、砂浆棒快速法、碳酸盐圆柱体法等不同试验方法对碱活性进行了研究,试验结果表明:料场部分骨料具有潜在危害性反应的碱活性。为确保混凝土的耐久性和工程安全,应严格控制工程所用水泥的碱含量及采取其它工程措施来抑制碱—骨料反应。

There are a lot of aggregates used in the section from Taocha to Shahe along the Middle Line of the South-to-North Water Diversion Project. Because of the complexity of AAR, the activity of aggregates is determined by the different methods. AAR has the character of slow-reaction alkali activity. The time for concrete to form crack because of expansion can last several decades. The aggregates have been determined on alkali reactivity potential by petrography method, accelerated mortar bar method, small rock column method. The results show the aggregates include alkali reactivity aggregates. To insure safety of the project, the alkali content of cement must be controlled strictly, or the others preventive measures against AAR must be used.