Effects of biochar on cement stabilised peat soil. Issue 3 (29th August 2019)

• Record Type: Journal Article
• Authors: Lau, Jeffrey; Biscontin, Giovanna; Berti, Debora
• Is Part Of: Proceedings of the Institution of Civil Engineers. Volume 172:Issue 3(2019:Aug.)
• Page Start: 1
• Page End: 31
• Publication Date: 2019-08-29
• Subjects: Geotechnical engineering -- environment -- strength & testing of materials; Soil stabilization -- Periodicals; Geotechnical engineering -- Periodicals; Grouting (Soil stabilization) -- Periodicals; 624.1513605
• DOI: 10.1680/jgrim.19.00013
• Languages: English
• ISSNs: 1755-0750

Abstract

Abstract : Peat is a soft soil with very high organic content, which makes it highly susceptible to extreme differential settlement. Although cement stabilisation is highly effective, it is not a common practice due to the high cost of treatment associated with large amount of binder dosage. In this paper, the use of a novel material, biochar as a potential replacement for cement and as an alternative filler to sand, was investigated. Biochar is more sustainable than traditional construction materials and has carbon sequestration ability. It could potentially be cheaper than cement or sand, depending on the source of feedstock used. Cement treated peat with sand was used as a benchmark to assess the performance of biochar enhanced cement treated peat. The samples with biochar finer than 75 μ m performed better than sand equivalent, over 50 % increase in compressive strength. Furthermore, it was found that the samples with 100 kg/m 3 cement and 400 kg/m 3 biochar had comparable performance to the control sample with 200 kg/m 3 cement only, without biochar, highlighting the potential of biochar to partially replace cement. Scanning Electron Microscopy and X-ray Diffraction tests results showed that the mechanisms behind the performance gain in biochar samples are of both mechanical and chemical nature.