再生骨料吸水返水特性及其对混凝土收缩性能的影响

Construction and demolition waste(C&D waste) has become the largest number of solid waste in the city, accompanied with the application of the urbanization process, rural construction and reinforcement of the old city. The utilization of C&D waste is an inevitable trend. Nowadays, the most common way is to prepare recycled aggregate(RC) for concrete and cement products by C&D waste..A number of previous studies have been done on recycled aggregate and the 28d’s and even long-term properties of recycled aggregate concrete(RAC). The issue of standards promotes the engineering practice of RAC. However, few research on the water absorption and desorption properties and its influence on shrinkage of RAC is reported in literature..This study focus on the water absorption and desorption properties of recycled aggregate and the shrinkage of RAC. The study is to determine the water exchange behavior between recycled aggregate and cement paste as well as its influence on shrinkage of RAC.

随着我国城市化进程的加快、新农村建设的推进以及大规模旧城改造工程的实施，我国建筑垃圾已经成为城市排放数量最大、最集中的固体废弃物。建筑垃圾的综合利用势在必行，目前最主要的资源化利用途径是制备再生骨料并用于生产混凝土、砂浆及水泥制品。.各国学者就再生骨料性质及其对再生混凝土28d及长期力学性能和耐久性的影响开展了大量研究，取得了丰硕成果，相关标准规范的出台也推动了再生骨料混凝土工程应用。然而针对再生骨料吸水特性及其对混凝土收缩性能影响机理的研究尚不多见。.本课题拟结合再生骨料吸水返水特性，开展再生混凝土收缩性能的研究，旨在探索再生骨料与混凝土的水分交换规律，从而进一步探究其对再生混凝土的收缩的影响。

随着我国城市化进程的加快、新农村建设的推进以及大规模旧城改造工程的实施，我国建筑垃圾已经成为城市排放数量最大、最集中的固体废弃物，目前最主要的资源化利用途径是制备再生骨料并用于生产水泥混凝土等建筑材料及制品。本项目围绕再生骨料混凝土制备和应用中的关键科学问题，系统研究再生骨料吸水特性和界面过渡区性能，揭示了再生骨料与混凝土的水分交换规律；采用非接触式及接触式两种收缩测试方法，探究了再生骨料对再生骨料混凝土收缩的影响规律，并对自生收缩和干燥收缩加以区分，建立收缩与骨料含水状态的联系，并提出基于附加用水量的再生混凝土配合比设计方法。