Cleaner geopolymer prepared by co-activation of gasification coal fly ash and steel slag:durability properties and economic assessment  

作　　者：Xian Zhou Xia Chen Ziling Peng Yongmen Zhou Yan Li Wang Jian Zeyu Fan Yuchi Chen 

机构地区：[1]Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China [2]Jiangxi Research Center on Hydraulic Structures,Jiangxi Provincial Institute of Water Sciences,Nanchang 330029,China [3]Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of Environmental Science & Engineering》2023年第12期109-121,共13页环境科学与工程前沿（英文）

基　　金：funded by the Jiangxi Academy of Water Science and Engineering Open Project Fund(No.2021SKSG04);the National Natural Science Foundation of China(No.51979011);the Central Non-Profit Scientific Research Fund for Institutes(Nos.CKSF2021483/CL,CKSF2023359/HL,and CKSF2023397/HL);the Knowledge Innovation Program of Science and Technology Bureau of Wuhan,China(No.CKSD2022360/CL)。

摘　　要：Geopolymer is a material with high early strength.However,the insufficient durability properties,such as long-term strength,acid-base resistance,freeze-thaw resistance,leaching toxicity,thermal stability,sulfate resistance and carbonation resistance,restrain its practical application.Herein,a longterm stable geopolymer composite with high final strength(ASK1)was synthesized from shell coal gasification fly ash(SFA)and steel slag(SS).Additionally,a geopolymer composite with high early strength(ASK2)was also synthesized for comparison.The results showed that ASK1 exhibited better performance on freezing-thawing resistance,carbonization resistance and heavy metals stabilization compared to the ASK2 at long-term curing.Raising the curing temperature could accelerate the unconfined compressive strength(UCS)development at initial curing ages of 3 to 7 d.Both ASK1 and ASK2 exhibited excellent acid-base and sulfate corrosion resistance.An increase for UCS was seen under KOH solution and MgSO_(4)solution corrosion for ASK1.All leaching concentrations of heavy metals out of the two geopolymers were below the standard threshold,even after 50 freezingthawing cycles.Both ASK1 and ASK2 geopolymer concrete exhibited higher sustainability and economic efficiency than Portland cement concrete.The result of this study not only provides a suitable way for the utilization of industrial solid waste in civil and environmental engineering,but also opens a new approach to improve the long-term stabilities of the geopolymers.

关 键 词：GEOPOLYMER Shell coal gasification fly ash Steel slag Heavy metal SOLIDIFICATION/STABILIZATION Durability 

分 类 号：S216[农业科学—农业机械化工程]