耦合激发炉渣基水泥净浆力学性能研究

Study on the Mechanical Properties of Slag-Based Cement Paste under Coupled Excitation

摘要:

炉渣是煤炭燃烧后产生的残留物，大量堆放不仅占用土地资源，还对环境造成负面影响。炉渣富含二氧化硅和氧化铝等活性物质，常被用作矿物掺合料以改善混凝土性能。然而，炉渣基胶凝材料的研究仍然处于起步阶段，尤其在激发机制、力学性能影响因素及微观结构演变规律等方向研究相对缺少。重点分析了机械-化学耦合激发作用下炉渣基水泥净浆的力学性能及微观结构演变规律。首先，研究了研磨参数对炉渣粒径分布的影响；然后，探讨了耦合激发参数及养护龄期等因素对炉渣基水泥净浆的抗压和抗折强度及其力学活性的影响；最后，通过SEM、XRD、FTIR等微观表征手段分析了炉渣基水泥净浆的水化产物、官能团和微观结构的变化以期揭示耦合激发途径对炉渣基水泥净浆力学性能的影响机制。结果表明，在最佳的耦合激发条件下，炉渣基水泥净浆在标准养护28 d后，抗折和抗压强度分别比水泥净浆(基准组)提升了19.8%和29.1%，Ⅰ型和Ⅱ型C-S-H凝胶物相含量分别比基准组增加了71.4%和58.3%。最佳激发条件为球料比18∶1、球磨时间20 min、碱激发剂总掺量1.5%、Ca(OH)₂与Na₂(SO)₄的摩尔比2∶3。耦合激发后的炉渣促进了水泥基材料的水化反应，生成了更多的C-S-H凝胶并形成致密的微观组织结构，有效提升了炉渣的力学活性和再生利用率。本研究为制备低碳环保的可持续胶凝材料提供了新的思路和方法。

Abstract:

Slag， a byproduct of coal combustion， occupies significant land area when piled in large quantities， leading to land resources wasteage and landscape degradation. Rich in silica， alumina and other active substances， slag is often used as mineral admixtures in concrete to enhance its performance. However， research on slag-based cementitious materials is still in its early stages， particularly in areas such as excitation pathways， factors influencing mechanical properties ， and microstructural evolution. Therefore， this paper investigates the mechanical properties and microstructural evolution of slag-based cement mortar under coupled mechanical-chemical excitation. Firstly， the influence of grinding parameters on the particle size distribution of slag is discussed. Then， the effects of coupled excitation parameters and curing age on the compressive and flexural strength and mechanical activity of slag-based cement mortar are investigated. Finally， SEM， XRD and FTIR are used to study the changes in hydration products， functional groups， and microstructures of slag-based cement paste， aiming to elucidate the mechanism by which coupled excitation pathways influence mechanical properties. Under optimal coupled excitation conditions， the compressive and flexural strengths of slag-based cement paste， after 28 d of standard curing， increased by 19.8% and 29.1%， respectively， compared to the benchmark cement mortar. The contents of type I and type II C-S-H gel phases increased by 71.4% and 58.3%， respectively， compared to the benchmark cement mortar. Indicating more C-S-H gel formation. The optimal conditions were a material ratio of 18∶1， ball milling time of 20 min， total alkali exciter dosage of 1.5%， and a molar ratio of Ca（OH）₂ and Na₂（SO）₄ of 2∶3. This coupled excitation promotes the hydration reaction of the cementitious materials， enhances C-S-H gel generation and forms a denser microstructure， thereby significantly improving the mechanical activity and regeneration efficiency of slag. This study offers new insignts and methods for preparing low-carbon， environmentally friendly and sustainable cementitious materials.