工业固体废弃物材料制作冷粘结人造轻骨料的研究进展

Research Advances in Cold-bonded Artificial Lightweight Aggregates Made from Industrial Solid Waste Materials

利用固体废弃物制作的冷粘结轻质骨料作为新型环保材料,满足资源再利用和节约能源、减少环境污染以及可持续发展战略的要求,是设计环保型混凝土的主要研究方向和推广方向。目前,提高绿色人造轻质骨料混凝土性能的重要手段之一就是克服人造轻骨料的缺陷,如吸水率大、坚固性差、孔洞多、干裂等。现有利用固废制备的人造轻骨料性能提升方式主要从造粒工艺、养护制度着手,如CO_(2)养护、烧结养护、挤压造粒等。同时通过调整固体废弃物材料种类、掺量也可以有效提升人造轻质骨料的性能。此外,借助不同的微观分析手段(如扫描电镜、水化热分析、热重分析、X射线分析等),并通过分析骨料力学性能、物理性能的影响因素,如化学组成、造粒设备参数等,也可以优化出有效提升人造骨料性能的方法,如纤维增强、碱性处理等。本文主要总结了工业固体废物的种类及造粒性能,综述了人造轻骨料的造粒方式、养护工艺、力学强度、物理性能和微观性能等研究进展,并指出了未来人造轻骨料的研究任务和完善方向。

Cold-bonded lightweight aggregates(CBLAs)made from solid waste are used as a new type of eco-friendly material to meet the requirements of resource reuse,energy savings,environmental pollution reduction and sustainable development strategies.It is the main research and promotion direction for designing eco-efficiency concrete.Recently,one of the important means to enhance the performance of green concrete with CBLAs has been to improve the defects of CBLAs,such as high-water absorption,poor firmness,numerous holes,and dry cracks.The existing methods for improving the properties of CBLAs prepared from solid waste mainly start from the granulation process and curing system,such as CO_(2)curing,sintering curing,and extrusion granulation.Furthermore,the performance of CBLAs can also be effectively improved by adjusting the type and dosage of solid waste materials.In addition,with the help of different microscopic analysis methods(scanning electron microscopy,thermal analysis of hydration,thermogravimetric analysis,X-ray analysis),and by analyzing the factors affecting the mechanical properties and physical properties of CBLAs,such as chemical composition,granulation equipment parameters,and using methods such as fiber reinforcement and alkaline treatment,the performance of CBLAs can also be optimized.The types and applications of industrial solid wastes,granulation methods,curing processes,mechanical strength,physical properties and microscopic properties of CBLAs are mainly reviewed,and future research tasks and improvement directions of CBLAs are also proposed in this paper.