State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China; Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China; Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Sci Total Environ. 2020 May 20;718:137422. doi: 10.1016/j.scitotenv.2020.137422. Epub 2020 Feb 19.
This study extends the application of pyrolyzed biochar and investigates its influence on the mechanical, sorption and microstructure properties of magnesium phosphate cement mortar. Biochar was produced by the pyrolysis of wheat straw biomass by controlled burning and its replacement level was kept up to 1.5%. At the age of 30 days, the compressive and flexural strength of mortar containing 1.5% biochar was 17.3% and 9.0% higher as compared to the control mortar, which was associated with the micro-filler and internal reservoir effect of biochar particles. Inclusion of biochar considerably improved the resistance of magnesium phosphate cement in the water environment. Sorptivity and water absorption of mortar containing 1.5% biochar was reduced by 33.8% and 25% respectively than the control mortar. Biochar densified the microstructure of mortars by filling the microcracks and blocking the pores. X-ray diffraction and Fourier transform infrared spectroscopy did not provide any information about the formation of new hydration products. Elemental analysis of mortar samples using energy dispersive spectroscopy showed the presence of some elements, which indicates the possibility of new hydration products. Based on the positive results in this study, future study will include the detailed chemical effect of biochar on magnesium phosphate cement.
本研究扩展了热解生物炭的应用范围，并研究了其对磷酸镁水泥砂浆的力学性能、吸附性能和微观结构性能的影响。生物炭是通过控制燃烧小麦秸秆生物质热解制成的，其替代水平保持在 1.5%。在 30 天龄时，含有 1.5%生物炭的水泥砂浆的抗压强度和抗弯强度分别比对照水泥砂浆高 17.3%和 9.0%，这与生物炭颗粒的微填料和内部储库效应有关。生物炭的加入极大地提高了磷酸镁水泥在水环境中的耐腐蚀性。含有 1.5%生物炭的水泥砂浆的吸水性和吸湿性分别比对照水泥砂浆降低了 33.8%和 25%。生物炭通过填充微裂缝和堵塞孔隙来使水泥砂浆的微观结构更加致密。X 射线衍射和傅里叶变换红外光谱没有提供关于新水合产物形成的任何信息。使用能量色散光谱对砂浆样品进行的元素分析表明存在一些元素，这表明可能形成了新的水合产物。基于本研究的积极结果，未来的研究将包括生物炭对磷酸镁水泥的详细化学影响。
