锂尾矿混合砂混凝土强度及耐久性试验研究  

Experimental study on strength and durability of lithium tailings mixed sand concrete

作　　者：丁蕴斌 石齐 DING Yunbin;SHI Qi(Jiangxi Building Materials Research and Institute Co.Ltd.,Nanchang 330000,China)

机构地区：[1]江西省建材科研设计院有限公司,江西南昌330000

出　　处：《新型建筑材料》2025年第3期118-122,145,共6页New Building Materials

基　　金：江西省科技厅重点研发计划项目(20214BBG74002)。

摘　　要：采用锂尾矿砂等质量替代部分机制砂,研究了锂尾矿砂替代率对混合砂颗粒级配、形貌以及混凝土抗压强度和耐久性的影响。结果表明:锂尾矿砂属于含粉量较大的细粒级尾砂,掺入锂尾矿砂能改善机制砂的颗粒级配及颗粒形貌;与纯机制砂组相比,当锂尾矿砂替代率为30%时,混凝土28 d抗压强度提高了5.1%,28、180 d收缩率分别减小了7.7%、15.3%,28 d电通量减小了18.7%,200次冻融循环后质量损失率为3.22%,相对动弹性模量为72.5%,混凝土内部孔隙较少,微观结构充分密实,综合性能最佳;锂尾矿砂混凝土的抗冻等级均可达到F200。Using lithium tailings sand to partially replace machine-made sand with the same mass,this paper investigates the effects of different substitution rates of lithium tailings sand on the particle size distribution,particle morphology,compressive strength,and durability of concrete.The results show that lithium tailings sand is a fine-grained tailings with a high powder content.The addition of lithium tailings sand can improve the particle size distribution and particle morphology of the sand mixture.Compared with the pure machine-sand group,when the substitution rate of lithium tailings sand is 30%,the compressive strength of concrete at 28 days increased by 5.1%.The shrinkage rates at 28 days and 180 days were reduced by 7.7%and 15.3%,respectively.The electrical flux at 28 days decreased by 18.7%.After 200 freeze-thaw cycles,the mass loss was 3.22%,and the relative dynamic elastic modulus was 72.5%.The concrete had fewer internal pores and a more compact microstructure,resulting in the best overall performance.The freeze-thaw resistance of lithium tailings sand concrete can reach the F200 standard.

关 键 词：锂尾矿 混合砂 混凝土 抗压强度 耐久性 

分 类 号：TU528.041[建筑科学—建筑技术科学]