This present research deals with the optimization study of biocement mortar made of biosilica, biochar, and egg shell waste powder to reduce the cement content up to 35 wt.%. The main purpose of this present study was to optimize the pozzolanic contents such as biosilica, biochar, and calcite egg shell particle in the setting time and water vapour transmission rate (WVTR) and compression strength of biocement mortar and how these bio-wastes turn to valuable material. The biocement mortar cubs were prepared using the Taguchi L₉ design pattern and analysed followed by grey relational approach. The biosilica particle used here was extracted from rice husk ash followed by thermo-chemical method. Similarly, the porous biochar was prepared from rice straw followed by low-temperature pyrolysis. The egg shell waste powder was prepared via high-energy ball mill for about 4 h followed by sieving process to confirm the uniform particle size equal to 1 µm. The compression strength, WVTR, and final setting time were measured after the successful ageing of cement cubes for about 28 days. According to analysis, the experimental plan A3B1C3 gives overall best rank among other experimental patterns with the GRG of 0.705. Moreover, the weight percentage of biochar directly influences the overall performance of cement mortar cubes rather than biosilica and egg shell particles. The confirmation study revealed improvement in grey relational grade of 1.72%, which is equal to the high compression strength of 55.101 MPa, lower WVTR of 1.6E⁻⁶ kg/m²s at 28 °C, and lower final setting time of 521 min.

本研究涉及由生物二氧化硅、生物炭和蛋壳废粉制成的生物水泥砂浆的优化研究，以将水泥含量降低至 35 wt.%。本研究的主要目的是优化生物水泥砂浆的凝固时间和水蒸气透过率（WVTR）和抗压强度等火山灰成分，如生物二氧化硅、生物炭和方解石蛋壳颗粒，以及这些生物废物如何转化为有价值的材料。使用 Taguchi L ₉制备生物水泥砂浆幼崽设计模式并分析其次是灰色关联方法。这里使用的生物二氧化硅颗粒是从稻壳灰中提取的，然后是热化学方法。同样，多孔生物炭是由稻草制成，然后进行低温热解。蛋壳废粉通过高能球磨机制备约 4 小时，然后进行筛分过程以确认均匀粒径等于 1 µm。在水泥立方体成功老化约 28 天后测量抗压强度、WVTR 和最终凝固时间。根据分析，实验方案A3B1C3在其他实验模式中总体排名最好，GRG为0.705。此外，生物炭的重量百分比直接影响水泥砂浆立方体的整体性能，而不是生物二氧化硅和蛋壳颗粒。⁻⁶  kg/m ² s 在 28 °C 下，最终凝固时间较低，为 521 分钟。