基于微区玻化机制废弃玻璃粉活性与胶凝性及其混凝土性能的研究

Currently, waste glass of more than 90% s has had a deteriorated effect on the occupation of land and the ecological environment and became a serious problem. It had been demonstrated that the waste glass powder had potential characteristics such as hydraulicity and pozzolanicity. This project proposed a micro area vitrification methods: waste glass was first grinded into tiny powder and processed rich pozzolanicity waste glass power under the proper heated treatment conditions. Through controlling the degree of supercooling and reducing melt surface tension, waste glass powder was pressed above submicron scale (0.1-1 μm) and more than 90% of activity index was obtained for 28 days. Based on the comprehensive understanding of the relationship of compositions, structures and properties of waste glass powder. As concrete cementitious material, the waste glass powder is replaced by partial cement, and the relationship of composition, its potential activity and excitation mechanism would be revealed in this project. From the composite system of thermodynamics, materials processing theory, interfacial chemistry and physics, structure optimization, and characteristic parameters of particle group, waste glass powder was proposed for the concrete with cementious effects. The hydration products, microstructure of concrete containing waste glass powder would be investigated systematically, and theoretical and technical basis are provided for waste glass resource utilization in the future.

国内废弃玻璃90%未得到充分利用，已成占用土地和影响生态环境的突出问题。研究证实，废弃玻璃粉具有潜在水硬性和潜在火山灰性。申请者提出"微区玻化"方法，把废弃玻璃研磨成微小粉末，在适当热处理制度下形成富有火山灰性的废弃玻璃粉；通过控制过冷度和减低熔体表面张力使废弃玻璃粉在亚微米尺度（0.1-1μm）上进行，使废弃玻璃粉28天活性指数达到90%以上；在全面认识废弃玻璃粉本身的组成、结构和性能关系的基础上，把废弃玻璃粉作为混凝土掺合料替代部分水泥， 阐明废弃玻璃粉的组成特性与其潜在活性的关系及其激发机理，开发废弃玻璃粉作为混凝土胶凝材料；从复合体系的热力学、过程理论、界面化学和物理、结构优化、颗粒群特征参数等角度，提出适合混凝土胶凝效应使用的废弃玻璃粉，系统研究废弃玻璃粉混凝土的水化产物、微观结构特征，为废弃玻璃资源化利用推广提供理论和技术依据。

每年废弃玻璃大约占全球固体废弃物的7%。如何对废弃玻璃进行资源化再利用已经成为一个亟待解决的问题。项目研究了玻璃粉—水泥复合胶凝体系的强度、玻璃粉活性指数、微观结构、水化度、工作性能等方面的变化规律及内在机理。获得的重要结果有：形成微米级和亚微米级玻璃粉制备工艺体系，得出了球磨时间为45min~60min的玻璃粉粒径分布最佳，经济效益做好；玻璃粉最佳掺量在30%左右，当玻璃粉掺入大于30%将大幅度降低胶凝体系强度；不同的化学激化剂对胶凝体系强度影响较大，采用4%Na2SO4作为化学激化剂可以有效提高胶凝体系的前期强度；玻璃粉掺入使得前期微观结构较为疏松，水化后期，掺玻璃粉与未掺玻璃粉的试块截面形貌相差不大，水化产物均已发展完全，并形成了致密的结构体系；化学激化剂可以有效改善复合胶凝材料的微结构，4%Na2SO4掺入激发时，生成的纤维状水化产物和网络结构比未掺激发剂的硬化浆体更完善，生成了大量的水化产物，可以有效激化玻璃粉火山灰强度；亚微米玻璃粉的颗粒粒径较水泥颗粒的更小，可均匀填充在水泥颗粒之间，使颗粒间的滑移阻力减小，亚微米玻璃粉作为胶凝材料掺入水泥砂浆中，可以改善浆体的流动度，提高工作性；玻璃粉掺入可以有效降低水化热峰值，降低混凝土浇筑温度峰值，减小了混凝土的温度应力，可以用于大体积混凝土浇筑体系中；玻璃粉可以有效抑制混凝土的ASR，玻璃粉对ASR膨胀的抑制作用随玻璃掺量增加而增强，相较于玻璃粉粒径，玻璃粉掺量对ASR膨胀的抑制作用的影响更大。本项目提出的适合混凝土胶凝效应使用的废弃玻璃粉，为废弃玻璃资源化利用推广提供理论和技术依据。