This study is aimed at assessing the synergy of the biochar utilization and early age CO2 curing on the mechanical performance, hydration and CO2 uptake in cementitious materials. Three different biochars Bamboo biochar (BBC), Peanut Husk Biochar (PHBC) and Rice Husk Biochar (RHBC) were utilized with dosages up to 5 % by mass of cement and their influence under water curing and early age CO2 curing was studied. Analytical studies using FTIR, XRD, TGA, SEM-EDS were extended on optimum biochar mixes for characterizing the microstructure, hydration, carbonation and CO2 uptake of various biochar based mixes. The optimum dosage was found to be 1 % for BBC & PHBC while it is 2 % in RHBC from a strength perspective. Calcium carbonate polymorphs – amorphous CaCO3 and aragonite are found to be dominant products besides other hydration products. The biochars porous surface ability to enable hydration products precipitation is revealed. Early age CO2 curing resulted in 23 % improved degree of hydration and 19 % improved CO2 uptake with 2 % rice husk biochar based mix compared to control mix without biochar. The improved early age strength with 48 h CO2 curing at flue gas CO2 concentration of 17 % and under ambient conditions were found to be promising aspects for implementation of this method in an industrial set up for production of carbon sinking cementitious products.

中文翻译：

---

农用生物炭基水泥砂浆的性能、微观结构和固碳潜力


本研究旨在评估生物炭利用和早期 CO2 固化对胶凝材料的机械性能、水化和 CO2 吸收的协同作用。使用三种不同的生物炭竹生物炭 （BBC）、花生壳生物炭 （PHBC） 和稻壳生物炭 （RHBC），用量高达 5% 的水泥质量，并研究了它们在水养护和早期 CO2 养护下的影响。使用 FTIR、XRD、TGA、SEM-EDS 的分析研究扩展到最佳生物炭混合物上，以表征各种生物炭基混合物的微观结构、水合、碳化和 CO2 吸收。发现最佳剂量是BBC和PHBC的1%，而从强度的角度来看，RHBC的剂量是2%。碳酸钙多晶型物 – 无定形 CaCO3 和文石被发现是除其他水合产物外的主要产品。揭示了 biochars 多孔表面能够沉淀水合产物的能力。与不含生物炭的对照混合物相比，早期 CO2 固化导致 2% 稻壳生物炭基混合物的水化程度提高 23%，CO2 吸收率提高 19%。在烟气 CO2 浓度为 17% 的条件下，在环境条件下进行 48 小时的 CO2 固化，提高早期老化强度是在生产碳沉式胶凝产品的工业装置中实施该方法的有前途的方面。