摘要
为研究金尾矿粉取代水泥对低强混凝土力学性能的影响,通过金尾矿粉等质量取代0~30%水泥,研究其对C25混凝土凝结时间以及力学性能的影响,并采用扫描电镜(SEM)和X射线衍射仪(XRD)等手段表征硬化浆体的水化产物、微观形貌。结果表明,金尾矿粉作为辅助胶凝材料能延长C25混凝土的凝结时间,金尾矿粉掺量在30%范围内,坍落度和凝结时间均可满足普通硅酸盐水泥标准要求。C25混凝土的抗压强度、轴心抗压强度、静弹性模量,均随着金尾矿粉掺量的增加,呈现出先增加后降低的趋势,在掺量5%时出现峰值。随着养护龄期的增加,金尾矿粉颗粒表面被水化产物覆盖,结构紧密孔隙较少,表现出良好的力学性能。但随着金尾矿粉替代率的增加,水化产物减少微观结构松散,力学性能降低。
In order to investigate the impacts of tailings powder substitution for cement on the mechanical properties of low-strength concrete, this work replaced 0~30% of cement by mass with tailings powder. Its effects on the setting time and mechanical properties of C25 concrete, and characterized the hydration products and microstructure of hardened paste was analyzed using scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results indicate that gold tailings powder, as an auxiliary cementitious material, can prolong the setting time of C25 concrete. Within the range of 30% gold tailings powder substitution, both slump and setting time meet the requirements of ordinary Portland cement standards. The compressive strength, axial compressive strength, and static modulus of elasticity of C25 concrete show a trend of initially increasing and then decreasing with increasing gold tailings powder content, with a peak observed at a substitution rate of 5%. SEM and XRD analyses reveal that with increasing curing age, the surface of gold tailings powder particles is covered by hydration products, resulting in fewer and more tightly packed pores, exhibiting favorable mechanical properties. However, as the substitution rate of gold tailings powder increases, the hydration products exhibit a looser microstructure, leading to a decrease in mechanical performance.
作者
牟宏霖
李金勇
MU Honglin;LI Jinyong(Nanping Wusha Expressway Co.,Ltd.,Nanping,Fujian 354200,China)
出处
《水利与建筑工程学报》
2024年第3期189-195,共7页
Journal of Water Resources and Architectural Engineering
基金
福建省科技厅引导性项目(2022Y0079)。
关键词
金尾矿粉
C25混凝土
力学性能
微观结构
gold tailing powder
C25 concrete
mechanical properties
microstructure
