Department of Building, School of Design and Environment, National University of Singapore, 4 Architecture Drive, Singapore 117 566, Singapore.
Department of Building, School of Design and Environment, National University of Singapore, 4 Architecture Drive, Singapore 117 566, Singapore.
Sci Total Environ. 2019 Apr 20;662:952-962. doi: 10.1016/j.scitotenv.2019.01.269. Epub 2019 Jan 23.
This study explores influence of biochar particle size and surface morphology on rheology, strength development and permeability of cement mortar, under moist and dry curing condition. Experimental results show that the flowability and viscosity of cement paste is more affected by macro-porous coarser (or 'normal') biochar particles of size 2-100 μm (NBC) compared to fine (or 'ground' biochar), which is in the size range of 0.10-2 μm (GBC). Addition of both GBC and NBC accelerated hydration kinetics and improved early (1-day) and 28-day strength by 20-25% compared to the control. Water permeability, measured by capillary absorption was reduced by about 50% compared to control mortar, due to the addition of 0.50-1% NBC and GBC respectively. GBC is found to be more effective in minimizing loss in strength and water tightness under dry curing condition compared to the control and mortar with NBC and quartz filler respectively. In summary, findings from the study show that finer biochar particles offer superior performance in improving early strength and water tightness compared to normal biochar (with macro-pores), while 28-day properties are similar for mortar with both GBC and NBC respectively.
本研究探讨了生物炭粒径和表面形态对潮湿和干燥养护条件下水泥砂浆流变性、强度发展和渗透性的影响。实验结果表明，与细（或“研磨”）生物炭相比，宏观多孔较大粒径（2-100μm）的生物炭（NBC）对水泥浆的流动性和粘度影响更大，而细（或“研磨”）生物炭的粒径在 0.10-2μm 范围内（GBC）。与对照组相比，添加 GBC 和 NBC 分别将水化动力学加速，并将 1 天和 28 天强度提高 20-25%。由于分别添加了 0.50-1%的 NBC 和 GBC，与对照组和含有 NBC 和石英填料的砂浆相比，毛细管吸收法测量的水渗透率降低了约 50%。与对照组和分别含有 NBC 和石英填料的砂浆相比，GBC 在干燥养护条件下更有效地减少强度和水密性的损失。总之，研究结果表明，与具有大孔的普通生物炭（NBC）相比，更细的生物炭颗粒在提高早期强度和水密性方面表现出更好的性能，而 GBC 和 NBC 分别用于砂浆的 28 天性能相似。
