文献类型：期刊文献

中文题名：复合激发体系中矿粉对磷石膏基胶凝材料力学性能及孔隙结构的影响

英文题名：Influence of mineral powder on mechanical properties and pore structure of phosphogypsum-based cementitious materials in a composite activation system

作者：蒋基湘 徐桂弘 赵振华 邓兴辉 陈孜伟 李贺军 张燕

第一作者：蒋基湘

机构：[1]贵州师范大学材料与建筑工程学院,贵州贵阳550000;[2]贵州理工学院土木工程学院,贵州贵阳550000;[3]重庆交通大学土木工程学院,重庆400000;[4]贵州省建材产品质量检验检测院,贵州贵阳550000;[5]贵州磷化集团,贵州贵阳550000

第一机构：贵州师范大学材料与建筑工程学院,贵州贵阳550000

年份：2026

期号：1

起止页码：99-105

中文期刊名：混凝土

外文期刊名：Concrete

收录：;北大核心:【北大核心2023】；

基金：贵阳市科技计划项目(筑科合同[2024]-1-8);国家自然科学基金(52268065);贵州省科技计划项目(黔科合基础-ZK[2022]重点027);黔科合平台人才(GCC[2023]053)。

语种：中文

中文关键词：磷石膏;矿粉;力学性能;微观机理;比表面积分析;孔径分析

外文关键词：phosphogypsum;mineral powder;mechanical properties;micro-mechanism;specific surface area analysis;pore size analysis

摘要：为实现固体废物的高附加值利用,选用无水石膏、水泥、硫酸钾以及矿粉作为原材料。创新性地构建碱性-硫酸盐复合激发体系,系统探究矿粉掺量(10%~30%)对磷石膏基胶凝材料力学性能及孔隙结构的调控机制,探讨复合激发条件下矿粉掺量对磷石膏基胶凝材料(PGCM)力学性能及孔隙结构的影响。借助力学性能测试、X射线衍射分析(XRD)、扫描电子显微镜结合能谱分析(SEM+EDS)、比表面积与孔径分析等方法,探讨了不同矿粉掺量对磷石膏基复合胶凝材料力学性能、水化产物、微观形貌特征的影响,以及PGCM内部孔隙结构的变化规律。研究结果显示,矿粉掺量的增加会致使PGCM的早期力学性能下降,这表明矿粉具备缓凝效应。当矿粉掺量为30%时,相较于3 d龄期,7 d龄期的抗折、抗压强度增长幅度最大,分别达到了60%和220%。借助X射线衍射(XRD)、扫描电子显微镜(SEM)以及能谱分析(EDS)可知,样品中存在大量钙矾石和未水化的石膏。鉴于钙矾石晶体结构的特性,其膨胀性可用于补偿混凝土的收缩,进而提升混凝土的密实度与强度。除矿粉掺量为20%的样品孔径大部分处于4~7 nm,其余四组样品的孔径均分布在4 nm。材料中存在大量尺寸与形状各异的孔隙,如介孔、微孔、微裂缝等。在吸附和脱附过程中,这些不同类型的孔隙呈现出不同的吸附特性,导致吸附曲线与脱附曲线在全孔径段无法重合。孔隙结构的这种不稳定性,会进一步对材料的力学性能和耐久性产生影响。分形维数与28 d抗压强度之间存在一定的线性函数关系。为磷石膏在多领域的资源化利用提供了可供参考的理论依据与技术途径。
To achieve the high-value utilization of solid waste,anhydrous gypsum,cement,potassium sulfate,and mineral powder were selected as raw materials.An innovative alkaline-sulfate composite excitation system was constructed to systematically investigate the regulation mechanism of mineral powder content from 10%to 30%on the mechanical properties and pore structure of phosphogypsum-based cementitious materials,as well as to explore the effect of mineral powder content on the mechanical properties and pore structure of phosphogypsum-based cementitious materials(PGCM)under composite excitation conditions.By means of mechanical property testing,X-ray diffraction(XRD)analysis,scanning electron microscopy coupled with energy-dispersive spectroscopy(SEM+EDS),and specific surface area and pore size analysis,the effects of different mineral powder contents on the mechanical properties,hydration products,and micromorphological characteristics of PGCM were discussed,together with the variation law of the internal pore structure of PGCM.The results show that the increase in mineral powder content leads to a decrease in the early mechanical properties of PGCM,indicating that mineral powder has a retarding effect.When the mineral powder content is 30%,compared with the 3 d curing age,the flexural and compressive strengths at the 7 d curing age show the maximum growth rates,reaching 60%and 220%,respectively.XRD,SEM,and EDS analyses reveal that a large amount of ettringite and unhydrated gypsum are present in the samples.Owing to the structural characteristics of ettringite crystals,their expansibility can be used to compensate for concrete shrinkage,thereby improving the compactness and strength of concrete.Except for the samples with 20%mineral powder content,whose pore sizes are mostly in the range from 4 nm to 7 nm,the pore sizes of the other four groups of samples are distributed around 4 nm.The material contains a large number of pores with different sizes and shapes,such as mesopores,micropores,and microcracks.During the adsorption and desorption processes,these different types of pores exhibit distinct adsorption characteristics,resulting in the non-coincidence of adsorption and desorption curves across the entire pore size range.This instability of the pore structure will further affect the mechanical properties and durability of the material.There is a certain linear functional relationship between the fractal dimension and the 28 d compressive strength.It provides a referential theoretical basis and technical approach for the resource utilization of phosphogypsum in multiple fields.