Abstract
The utilisation of biochar, the carbon negative product of pyrolysis, reduces the carbon footprint of the cementitious composites as it possesses the potential to replace the consumption of Portland cement. In a systematic investigation, biochar was used as a partial cement replacement for up to 20 wt% in both cement pastes and mortars. A comprehensive experimental framework was conducted to evaluate the impact of biochar replacement on the performance of (i) cement paste in terms of hydration kinetics, rheology, strength development, porosity, and (ii) mortars in terms of mechanical, thermal, and transport properties. In addition, the durability of developed mortars, including freezing and thawing resistance, thermal resistance, acid (corrosion) resistance, flammability, and smoke production, were examined. The results revealed that lower replacement rates of cement with biochar (up to 5 wt%) do not substantially change the performance of cementitious composites. However, incorporating biochar in higher dosages (i.e., 20 wt%) influenced the hydration process, reduced flexural and compressive strengths by 49% and 29%, respectively, and increased the water absorption coefficient by 60% compared to control specimens. The same cement mortar demonstrated the most promising freeze-thaw (i.e., 98% relative residual compressive strength), acid resistance as well as considerably lower thermal conductivity. In addition, regardless of biochar content, mortars did not exhibit flammability. Therefore, this study demonstrated that despite specific technical issues, biochar can be successfully incorporated into high dosage to cementitious composite as an alternative binder with minimum environmental impacts to improve durability and insulating performance of mortars.
Original language | English |
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Article number | 115103 |
Number of pages | 13 |
Journal | Industrial Crops and Products |
Volume | 184 |
Early online date | 26 May 2022 |
DOIs | |
Publication status | Published - 15 Sept 2022 |
Bibliographical note
Funding Information:This research was funded in part by the National Science Centre, Poland within Project No. 2020/39/D/ST8/00975 (SONATA-16).
Publisher Copyright:
© 2022 The Authors
Keywords
- Biochar
- Cement
- Durability
- Hydration
- Mechanical strength
- Rheology
ASJC Scopus subject areas
- Agronomy and Crop Science