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Title:

Study on Mechanical and Microscopic Properties of Nickel–Copper-Contaminated Soil Solidified by Cement, Fly Ash and Desulfurization Gypsum Under Carbonization Condition

Accession Number:

01782059

Record Type:

Component

Availability:

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Order URL: http://worldcat.org/issn/03611981

Abstract:

The engineering characteristics of remediated soil are easily affected by CO2 erosion in nature. However, there are limited investigations on the mechanical and microscopic properties of heavy metal-contaminated soil. This study introduces effect of accelerated carbonization on the mechanical and microscopic properties of nickel–copper-contaminated soil, and the soil has been treated with a novel curing agent, formed by mixing cement, fly ash and desulfurization gypsum (CFG). The objective of the study is to ascertain CO2 erosion resistance of nickel–copper-contaminated soil solidified by CFG. Using unconfined compressive strength (UCS) tests, carbonization depth, X-ray diffraction, and scanning electron microscopy, the sample’s characteristics are investigated under different carbonization times and heavy metal ion concentrations. The results demonstrate that the UCS of samples of Ni0Cu0, Ni0.02, and Ni0.4 decrease with the increasing carbonization time, while that of Ni1, Cu1, and Ni1Cu1 increase initially and then decrease; in addition, when the concentration of heavy metals is lower, the effect of carbonization on UCS of samples is more significant. Moreover, the carbonization depth of samples increases with the increasing carbonization time, and the prediction model is given. Furthermore, the microscopic analysis demonstrates that calcium carbonate is the main carbonization product. The decomposition of hydrated calcium silicate gel leads to poor integrity of the structure and more pores produced in samples, which is the main reason for the decrease of the UCS in the process of carbonization. The outcomes of this investigation provide a reference for the durability in practical engineering of heavy metal-contaminated soil solidified by CFG.

Supplemental Notes:

© National Academy of Sciences: Transportation Research Board 2021.

Language:

English

Authors:

Wang, Qiang
Guo, Xiaoliang
Li, Man
Yang, Jingdong
Cui, Jinyang
Zhou, Wenjun

Pagination:

pp 379-392

Publication Date:

2022-2

Serial:

Transportation Research Record: Journal of the Transportation Research Board

Volume: 2676
Issue Number: 2
Publisher: Sage Publications, Incorporated
ISSN: 0361-1981
EISSN: 2169-4052
Serial URL: http://journals.sagepub.com/home/trr

Media Type:

Web

Features:

References (50)

Subject Areas:

Geotechnology; Highways

Files:

TRIS, TRB, ATRI

Created Date:

Sep 19 2021 3:13PM