城市生活垃圾焚烧灰渣作为混凝土细骨料的试验研究

This project is based on the research work that granulated blast furnace slag replaced natural sand as fine aggregate in concrete had been finished by proposer, and it will be studied that MSW (Municipal solid waste) incineration bottom ash is used in concrete as fine aggregate. MSW incineration bottom ash and granulated blast furnace slag are part of silicon and calcium mineral compounds by high temperature calcining, their physical characteristic is similar to the natural sand, and chemical composition is similar to the ordinary Portland cement clinker. MSW incineration bottom ash and granulated blast furnace slag all can be used in concrete as fine aggregate replaced naturel sand. Through water quench process of MSW incineration bottom ash, the method to improve the quality of MSW incineration bottom ash fine aggregate will be studied. Through studying of strength, chemical composition, potential hydraulic property, pore structure, harmful substances exuded and other characteristics of MSW incineration bottom ash, and based on analysis of relevant concrete experiment, the quality evaluation standard of MSW incineration bottom ash as fine aggregate for concrete will be established. Through trial mixing experiment of concrete, the method about mixing concrete using MSW incineration bottom ash fine aggregate will be proposed. It will be evaluated that environmental safety about the concrete used MSW incineration bottom ash fine aggregate through harmful substances exuded testing. Focus on the experimental research about mechanical properties and durability performance of concrete using MSW incineration bottom ash as fine aggregate, as a result of this research, basic experiment data and application suggestion would be provided in order to use MSW incineration bottom ash as fine aggregate in concrete for civil engineering. This project will expand ways about utilization of MSW and alleviate the contradiction between supply and demand of natural sand for civil engineering, a new ideas would be provided for creating the resources saving society.

本项目以申请人已完成的关于粒化高炉矿渣代砂混凝土研究为基础，拟对城市生活垃圾焚烧灰渣作为混凝土细骨料展开试验研究。垃圾焚烧灰渣与粒化高炉矿渣同属高温煅烧形成的硅钙质无机物，物理性质类似天然砂，化学成分接近水泥熟料，可代替天然砂用作混凝土细骨料。通过熔融水淬处理工艺，研究垃圾焚烧灰渣资源化二次加工方法；通过对垃圾焚烧灰渣颗粒强度、化学成分、潜在水硬性、细孔结构、有害物质渗出特性等的测试分析，并结合相关混凝土试验初步建立垃圾焚烧灰渣细骨料品质评定标准；通过混凝土配合试验，研究垃圾焚烧灰渣细骨料混凝土配合方法；通过垃圾焚烧灰渣细骨料混凝土有害物质渗出试验，来评估其环境安全性。重点通过试验考察垃圾焚烧灰渣细骨料混凝土强度特性和耐久性能，为开展在混凝土中使用城市生活垃圾焚烧灰渣细骨料提供基础试验数据和工程应用建议。该研究为加快废弃物循环利用，缓解建设用砂供需矛盾，创建资源节约型现代社会提供新思路。

随着我国城镇化进程的加速，城市生活垃圾产量迅速增加，垃圾的处理及再利用已成为一个急需解决的问题。垃圾焚烧灰渣是高温煅烧形成的硅钙铝氧化物，物理性质类似天然砂，有用作混凝土细骨料的潜质。本研究中，通过熔融水淬处理工艺、研究垃圾焚烧灰渣资源化加工方法；通过对垃圾焚烧灰渣颗粒强度、化学成分、潜在水硬性、细孔结构、有害物质渗出特性等的测试分析，并结合相关混凝土试验初步建立垃圾焚烧灰渣细骨料品质评定标准；通过混凝土配合试验，研究垃圾焚烧灰渣细骨料混凝土配合方法；通过有害物质渗出试验，评估垃圾焚烧灰渣细骨料混凝土环境安全性。研究中重点考察了垃圾焚烧灰渣细骨料混凝土强度特性和耐久性能。研究结果显示，熔融水淬处理工艺可以较大幅度地提高垃圾焚烧灰渣骨料特性，其密度、吸水率、压碎指标值等骨料特性均优于普通灰渣，普通垃圾焚烧灰渣及水淬灰渣有毒物质浸出量远小于国家标准；通过合理设计配合比，可以用生活垃圾焚烧灰渣配制出拌合性能合格的混凝土；生活垃圾焚烧灰渣代砂混凝土力学性能随代砂率的增加呈下降趋势，相对于普通垃圾焚烧灰渣细骨料混凝土，使用水淬灰渣细骨料混凝土的强度更接近天然砂混凝土；由于垃圾焚烧灰渣及水淬灰渣存在潜在水硬性，垃圾焚烧灰渣细骨料混凝土长龄期强度增长率要大于普通混凝土；生活垃圾焚烧灰渣细骨料混凝土的冻融、抗氯离子渗透、干燥收缩等耐久性能略低于普通混凝土。由上述研究结果可知，垃圾焚烧灰渣可以代替部分天然砂用作混凝土细骨料。该研究为加快城镇固体废物循环利用，缓解建设用砂供需矛盾，创建资源节约型现代社会提供新思路。