Investigation on solidified/stabilized behavior of marine soil slurry by lime-activated incinerated sewage sludge ash-ground granulated blast furnace slag under multifactor conditions  

作　　者：Zhao Sun Wenbo Chen Rundong Zhao Numan Malik Jianhua Yin Yonggui Chen 

机构地区：[1]Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong,999077,China [2]Department of Geotechnical Engineering,School of Civil Engineering,Tongji University,Shanghai,200092,China [3]College of Civil and Transportation Engineering,Shenzhen University,Shenzhen,518071,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第12期5264-5277,共14页岩石力学与岩土工程学报（英文）

基　　金：supported by the Research Grants Council of Hong Kong Special Administrative Region Government of China(Grant No.15210322);The National Natural Science Foundation of China(Grant No.42125701)is greatly appreciated.;The authors also acknowledge Research Centre for Resources Engineering towards Carbon Neutrality(Grant No.BBEJ)of Hong Kong Polytechnic University.

摘　　要：This study aims to evaluate the possibility of reusing treated marine clayey soils by stabilization/solidification(S/S)technology as geomaterial in reclamation projects from the aspects of engineering strength,chemical modification and environmental risk assessment.The lime-activated incinerated sewage sludge ash(ISSA)together with ground granulated blast furnace slag(GGBS)was employed as the binder.The multi-controlling factors including water content,curing time,salinity,and chemical compositions of mixing solution were taken into account to identify the S/S treated Hong Kong marine deposit(HKMD)slurry based on the strength tests,pH measurement,thermo-gravimetric(TG)analysis,X-ray diffractometer(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy coupled with energy-dispersive spectrometry(SEM-EDS)and toxicity characteristic leaching procedure(TCLP)tests,etc.The results show that the S/S treatment using lime-activated ISSA-GGBS can effectively enhance the strength of marine soil at the initial water content of 110%and 200%.The water content and curing time have a significant impact on the S/S treated HKMD.The pH of treated soils is higher than 11.1,which proves an alkaline environment for the reactions in the treated soil.A special case is the treated HKMD at 200%water content hydrated by MgCl_(2)solution,which has a low pH of 10.23 and maintains a slurry state.Based on the TCLP results,the leaching concentration of heavy metals from S/S treated HKMD is environmentally safe and meets Hong Kong standard for reusing treated soil with a low level of<0.2 mg/L.The content of main products such as calcium/magnesium silicate hydrate,ettringite or Friedel's salt depends on the chemical additions(e.g.distilled water,seawater,NaCl and Na_(2)SO_(4)).The products in the specimens mixed with MgCl_(2)solutions are mainly composed of Mg(OH)_(2),M-S-H and MgCO_(3),which is distinct with the neoformations in the other cases.Therefore,this study proves that the S/S treated soil slurry could be reused

关 键 词：Hong Kong marine deposits STABILIZATION/SOLIDIFICATION Engineering strength Physicochemical property Environmental risk assessment 

分 类 号：TU442[建筑科学—岩土工程]