Mechanical Properties and Leaching Characteristics of Geopolymer-Solidified/Stabilized Lead-Contaminated Soil
Ordinary Portland cement (OPC) is widely used in the solidification/stabilization of Pb-contaminated soils. However, many studies have suggested that the high content of Pb would degrade the mechanical properties of OPC-solidified/stabilized soils. This paper presents a new binder, geopolymer fine a...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Hindawi Limited
2019-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2019/6015769 |
| Summary: | Ordinary Portland cement (OPC) is widely used in the solidification/stabilization of Pb-contaminated soils. However, many studies have suggested that the high content of Pb would degrade the mechanical properties of OPC-solidified/stabilized soils. This paper presents a new binder, geopolymer fine aggregate (GFA), composed of ground granulated blast furnace slag, fly ash, CaO, and Na2SiO3. For comparison, OPC was used as a conventional binder. Mechanical properties and leaching characteristics are typically used to evaluate the effects of binders on solidified/stabilized soils. Nevertheless, limited information on the mechanical properties and leaching characteristics of the GFA-solidified/stabilized soils is available. This study thus investigated the mechanical properties and leaching characteristics of geopolymer-solidified/stabilized Pb-contaminated soil. Unconfined compressive strength test, permeability test, synthetic precipitation leaching procedure, simplified bioaccessibility extraction, phytoavailability extraction (with diethylene-triamine penta-acetic acid), sequential extraction procedure, mercury intrusion porosimetry, and scanning electron microscopy (SEM) were performed on OPC- and GFA-solidified/stabilized soil. The results showed that the GFA presented a better effect on the mechanical properties and leachability of the solidified/stabilized soils than the OPC-solidified/stabilized soils. The GFA-solidified/stabilized soil displayed considerably lower leachability, bioaccessibility, and phytoavailability of Pb and higher mechanical properties and chemical stability than the OPC counterpart. This study demonstrated that GFA had a better effect than OPC on the solidification/stabilization of Pb-contaminated soils. |
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| ISSN: | 1687-8086 1687-8094 |