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 µm 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.

Laboratory tests demonstrated that biochar filler added to Portland cement stabilized peat results in an increase of unconfined compressive strength, comparable with that of a sand filler. Strength increase is significantly higher when biochar is ground to a size below 75 µm. This paper investigates the changes in mineralogy, texture and microstructure during the early hydration of cement mixed with peat and biochar filler to identify the mechanisms responsible for the strength increase. The results show that the biochar surface catalyzes nucleation of hydration products. Labile carbon in biochar promotes carbonation, with precipitation of calcite within its cells and on its surface, as well as formation of hemi and monocarboaluminate, two stable AFm phases. For the ManuscriptClick here to access/download;Manuscript;Manuscript_Sep10_Final.docxBerti, February 8, 2020 larger fragments of biochar, the early hydration products do not reach the inner cells.Instead, the fine fragments tend to be fully covered leading to a more homogeneous spatial distribution of cement and voids.

Bei der Lagerung, dem Transport, der Gewinnung und Veredelung von Fettrohstoffen entstehen Abfallprodukte in allen Aggregatzuständen und deren möglichen Mischungen. Sie erstrecken sich von Staubresten und Tankschlämmen der Rohprodukte über Reaktions‐ und Trennabfälle der verschiedenen Prozeßstufen bis hin zu Papier‐ und Kunststoffabfällen von Verpackungsmaterialien. Viele dieser Abfallstoffe sind heute entweder vermeidbar oder – falls unvermeidbar – verwertbar. An praktischen Beispielen und Darstellungen wird diese branchenspezifische Problematik behandelt, wobei ökonomische und technologische Gesichtspunkte im Vordergrund stehen.

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