Microwave assisted concrete recycling is highlighted by a large number of research groups all over the world due to its potential for significant process benefit. In this paper, systematic experiments are established to study the microwave heating and aggregate recycling of dried and saturated concrete, respectively, investigating the effect of moisture content on heating results. The heating characteristics, cracks propagation, concrete damage and micro-structure variations were demonstrated. The temperature was higher in dried concrete under microwave heating, while the concrete damage and mortar-aggregate interface debonding were firstly occurred in saturated concrete. Recycled aggregates could be obtained by the combinations of mechanical process and microwave treatment in dried sample. While in saturated concrete, aggregates could be easily separated under relatively sufficient microwave power input. The results show that water content has the vital influence on concrete heating and aggregate separation results. The properties of recycled aggregates were tested to evaluate its further applications. The experimental results can provide a new approach to improve the microwave-assisted concrete aggregate recycling efficiency through the increment of water content.

由于微波辅助混凝土回收具有显着的工艺效益潜力，它受到世界各地大量研究小组的重视。本文通过系统试验分别对干混凝土和饱和混凝土的微波加热和骨料回收利用进行了研究，考察了含水率对加热效果的影响。展示了加热特性、裂缝扩展、混凝土损坏和微观结构变化。微波加热干燥后的混凝土温度较高，而饱和混凝土首先发生混凝土破坏和砂浆-骨料界面脱粘。通过机械加工和微波处理相结合的干燥样品可以获得再生骨料。在饱和混凝土中，在相对充足的微波功率输入下，聚集体可以很容易地分离。结果表明，含水量对混凝土加热和骨料分离结果有重要影响。测试再生骨料的性能以评估其进一步的应用。试验结果为通过增加含水量提高微波辅助混凝土骨料回收效率提供了一种新途径。