基于混合硅源煅烧的稻壳基NHL制备及性能研究

Preparation and Properties of Rice Husk-Based NHL Based on Calcination of Mixed Silica Sources

摘要: 针对传统天然水硬性石灰(NHL)原料依赖进口、环境兼容性不足的问题，本文以石灰石、稻壳灰和硅灰为原料煅烧制备稻壳基NHL，通过抗折抗压试验、X射线衍射、扫描电子显微镜、热重分析、凝结时间和流动度测试等多种手段，系统研究了所制石灰砂浆的力学性能、微观结构及工作性能，并采用粘结强度仪评估了修复砂浆在历史建筑清水砖墙修复中的应用效果。结果表明，通过混合硅源(LS-SF-RHA)制备的NHL，表现出最佳的抗压强度和力学性能，28天水化产物主要为C-S-H凝胶和CaCO₃。在实际应用中，该组砂浆展示出优异的粘结强度和良好的修复效果，且与历史墙体兼容性较好。此研究通过资源化利用稻壳废弃物，不仅减少了对进口NHL材料的依赖，还为历史建筑修复提供了一种低成本、生态型的解决方案，具有广泛的应用前景和显著的环境效益。

Abstract: Aiming at the problems of traditional natural hydraulic lime (NHL) raw materials relying on imports and insufficient environmental compatibility, this paper prepares rice husk-based NHL by calcining limestone, rice husk ash and silica fume, and systematically investigates the mechanical properties, microstructure and working of the resulting lime mortar by various means such as flexural and compressive tests, X-ray diffraction, scanning electron microscope, thermogravimetric analysis, setting time and fluidity tests, etc. The mechanical properties, microstructure and working properties, and the bond strength meter was used to evaluate the application effect of the restoration mortar in the restoration of clear water brick walls of historical buildings. The results showed that the NHL prepared by mixing silica sources (LS-SF-RHA) exhibited the best compressive strength and mechanical properties, and the hydration products at 28 days were mainly C-S-H gel and CaCO₃. In practical applications, this group of mortars demonstrated excellent bond strength and good restoration results with good compatibility with historic walls. This study not only reduces the dependence on imported NHL materials through the resourceful utilization of rice husk waste, but also provides a low-cost and ecological solution for the restoration of historic buildings, which has a wide range of application prospects and significant environmental benefits.