Mechanical and environmental properties of geopolymer-stabilized domestic waste incineration slag in an asphalt pavement base  

作　　者：Xiaoping Ji Bo Chen Xinze Dong Honglei Lu Xueyuan Zhang Shupeng He Tongda Wu 

机构地区：[1]School of Highway,Chang'an University,Xi'an 710064,China [2]No.1 Municipal Administration Institute,Xianyang Planning&Design Institute,Xianyang 712000,China [3]Hefei Municipal Design and Research Institute Co.Ltd.,Hefei 230041,China

出　　处：《Journal of Road Engineering》2023年第2期218-228,共11页道路工程学报（英文）

基　　金：This work was supported by the Fundamental Research Funds for the Central Universities,CHD(grant number 300102212906);the Key R&D Plan of Shaanxi Province(grant number 2023-YBSF-390);the Innovation Capability Support Program of Shaanxi(grant number 2022TD-07);the Xianyang City,Shaanxi Province,China 2019 Key Research and Development Program(grant number 2019k02-125).

摘　　要：Domestic waste incineration slag(WIS)includes fly ash and slag.Fly ash is classified as hazardous waste because it contains heavy metals.Most of slag are directly stacked or landfilled due to problems such as large output and low utilization rate.Harmless treatment is imminent.If WIS is used effectively in the road engineering,which can realize the high-quality and high-efficiency recycling of WIS,and it is of great significance to save resources and protect the environment.This study applies a geopolymer prepared from WIS fly ash as a stabilizing agent in WIS blending macadam for use as a pavement base mixture,and reports the mechanical properties(unconfined compressive strength,splitting strength,and resilience modulus)of the geopolymer-stabilized WIS blending macadam(GeoWIS).The leaching concentrations of harmful heavy metals of GeoWIS soaked in water were also investigated.Finally,the strength formation and heavy metal stability mechanisms were explored.The unconfined compressive strength,splitting strength,and compressive resilient modulus of GeoWIS all increased with increasing geopolymer content and decreasing WIS content.The strength of GeoWIS was derived from its geopolymerization and hydration products(C-S-H gel,N-A-S-H gel,and AFt).When the geopolymer content reached 12%–14%,the GeoWIS without natural macadam met the strength criterion of the asphalt pavement base.Through physical adsorption and chemical bonding,the geopolymer significantly reduced the leaching of harmful heavy metals.In GeoWIS with 50%WIS and stabilized with 10%geopolymer,the Cr,Ni,Cd,and Pb concentrations met the grade III groundwater standard.Concentrations of heavy metals leached from GeoWIS are low and exert little impact on environment.

关 键 词：Domestic waste incinerator slag Fly ash Geopolymer-stabilized macadam Heavy metal leaching concentration 

分 类 号：U414[交通运输工程—道路与铁道工程] U416.217