全固废地聚物稳定钢渣基层的性能及微观特性分析  

Performance and Microscopic Characteristics of Geopolymer Stabilized Steel Slag Roadbase with Full Solid-waste Reusing

作　　者：田中男 张争奇[2] 何勇海 雷伟 蒲昌瑜 孟会林 杨肖肖 TIAN Zhong-nan;ZHANG Zheng-qi;HE Yong-hai;LEI Wei;PU Chang-yu;MENG Hui-lin;YANG Xiao-xiao(Hebei Provincial Communications Planning,Design and Research Institute Co.Ltd.,Shijiazhuang 050091,Hebei,China;Key Laboratory of Highway Engineering in Special Area,Ministry of Education,Chang'an University,Xi'an 710064,Shaanxi,China;Hebei Transportation Investment Group Company Limited,Shijiazhuang 050091,Hebei,China)

机构地区：[1]河北省交通规划设计研究院有限公司公路建设与养护材料技术与装备交通运输行业研发中心,河北石家庄050091 [2]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064 [3]河北交通投资集团有限公司太行创新研究院低碳交通研究中心,河北石家庄050091

出　　处：《中国公路学报》2023年第12期131-142,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(52278428);河北省交通运输厅科技项目(2018-04);中央高校基本科研业务费专项资金项目(300203211211)。

摘　　要：为探索钢渣集料、粉煤灰、高炉矿渣粉全固废制备道路基层材料的可行性,利用工业固废胶凝潜力,开发地聚物稳定钢渣(GeoSS)基层材料,提出GeoSS混合料设计流程,并研究了不同硅铝质粉料剂量和碱用量对力学强度、干缩性能、碳减排效益、重金属浸出浓度的影响,最后利用X射线衍射(XRD)、红外光谱(FTIR)和扫描电子显微镜(SEM/EDS)分析了GeoSS混合料的地聚合反应和地聚物-钢渣界面特性。结果表明:GeoSS混合料具有优异的抗压强度和劈裂强度,总干缩系数远小于水泥稳定碎石C5,能够满足极重、特重交通的高速公路基层所需的承载能力和路用需求。相较于水泥稳定碎石C5,GeoSS混合料的碳排放当量最高可降低54.21%,具有显著的碳减排效益。地聚物胶凝产物通过物理吸附和化学结合,将固废原材料的重金属离子所封固,浸出液中Pb和其他重金属浓度分别满足Ⅳ级和Ⅲ级地下水标准,对道路周围环境的污染风险较低。粉煤灰和矿渣粉通过碱激发产生了水化硅铝酸钙(C-A-S-H)和水化硅铝酸钠(N-A-S-H)等胶凝产物;同时在地聚物结合料的碱性条件下,钢渣集料表面水化速率加快并产生胶凝化,生成了晶体产物水化石榴石和无定形产物C(N)-A-S-H,该反应以水化反应为主,伴随微弱的地聚合反应。钢渣集料表面产生的胶凝产物,有助于填充和密实地聚物与钢渣的界面过渡区,从而产生更强的界面黏结能力,从而提高GeoSS混合料的路用性能。可见,利用钢渣集料、粉煤灰、高炉矿渣粉全固废制备地聚物稳定钢渣用作道路基层材料是可行的,该研究可为固废基地聚物类基层材料的设计和应用推广提供参考。To explore the feasibility of fully reusing steel-slag aggregate,fly ash,and blast-furnace slag powder as roadbase materials,a geopolymer-stabilized steel slag(GeoSS)roadbase material was developed by utilizing the potential of industrial waste cementation.A GeoSS mixture design was proposed,and the effects of different amounts of silicon aluminum powder and an alkali agent on mechanical strength,dry shrinkage,carbon emission,and heavy metal leaching were investigated,and the microstructure characteristics of the GeoSS mixture were analyzed using X-ray Diffraction(XRD),Fourier Transform Infrared Spectroscopy(FTIR),Scanning Electron Microscope(SEM)and Energy Dispersive Spectrometer(EDS).The mixture showed excellent compressive and splitting strengths,and the total dry shrinkage coefficient was much smaller than that of cement-stabilized macadam.The GeoSS mixture met the bearing capacity and road use requirements of extremely heavy highway roadbases.The CO_(2) emission equivalent of the GeoSS mixture reached 54.21%less than that of cement-stabilized macadam C5.Geopolymer hydration products solidify heavy metal ions in solid waste raw materials through physical adsorption and chemical binding;the Pb and other heavy metals content in the leaching solution of the sample met the IV and III groundwater standards,respectively.Thus,the pollution risk to the environment surrounding the road is relatively low.Fly ash and slag powder generate cementitious products through alkaline activation reactions such as C-A-S-H and N-A-S-H,while the surface hydration rate of steel-slag aggregate increases under the alkaline conditions of the geopolymer binder,resulting in the formation of a crystal hydrated garnet and an amorphous product,C(N)-A-S-H.This is mainly a hydration reaction accompanied by a weak geopolymerization reaction.The cementitious products generated on the surface of steel-slag aggregate help to fill and compact the interface transition zone between the polymer and steel slag,resulting in stronger interfacial-bonding

关 键 词：路面工程 地聚物稳定钢渣 固废利用 低环境负荷路面 路用性能 微观特性 

分 类 号：U416[交通运输工程—道路与铁道工程]