混凝土骨料碱活性试验方法研究与成果应用

Study on the method of alkali aggregate reaction test and its application

由碱骨料反应造成的混凝土膨胀、开裂甚至破坏已经引起了各国的普遍重视,目前碱活性检验方法主要有岩相法、化学法和测长法等,这些方法对保证混凝土耐久性起到积极作用,但也存在其本身缺陷。对2类骨料碱活性试验方法的可靠性分别进行了研究,结果表明,ASTM C1260(快速砂浆棒法)对碱骨料的判定过于严格;ASTM C586碳酸盐骨料潜在碱活性标准试验方法(岩石柱法)中圆柱体试件试验的可靠性和可操作性不如棱柱体试件。研究成果应用于对进沪骨料、核电工程用骨料和高速铁路工程用骨料的碱活性评定工作中,有利于工程采取积极的预防措施,避免遭受碱骨料破坏损失。

Concrete expansion, cracking and even damage caused by alkali aggregate reaction has amused widespread attention in the world,the current alkali activity test methods of most countries are three kinds which are petrographic method, sol-gel expansion method and length measurement. These methods played a positive role in ensuring the durability of concrete, but has shortcomings. In this paper, the reliability of two kinds of alkali aggregate test methods are studied. The results showed that ASTM C1260（accelerated mortar bar method） in the determination of alkali aggregate is too strict,ASTM C586 test method for potential alkali reactivity of carbonate aggregate （rock column method）, the reliability and maneuverability of the test cylinder is not as good as the prismatic specimen. The research results are applied to the evaluation of alkali activity of aggregate in Shanghai constructions, high speed railway and nuclear power project,which is beneficial to take positive preventive measures and avoid loss of alkali aggregate damage.