冻融与硫酸盐作用下铁尾矿混凝土损伤性能研究  

Study on damage properties of iron tailings concrete under freeze-thaw and sulfate action

作　　者：李淑燕 王鸿源 冯海暴 LI Shuyan;WANG Hongyuan;FENG Haibao(School of Civil Engineering,Hebei University of Engineering,Handan,Hebei 056038,China;School of Civil Engineering,Cangzhou Jiaotong College,Cangzhou,Hebei 061110,China;CCCC First Harbor Engineering Company Limited,Tianjin 300461,China)

机构地区：[1]河北工程大学土木工程学院,河北邯郸056038 [2]沧州交通学院土木建筑工程学院,河北沧州061110 [3]中交第一航务工程局有限公司,天津300461

出　　处：《河北工业科技》2025年第2期128-136,共9页Hebei Journal of Industrial Science and Technology

基　　金：国家自然科学基金(52378245)。

摘　　要：为明晰铁尾矿混凝土在复杂环境下的耐久性能,在冻融循环和硫酸盐侵蚀耦合作用下,研究了铁尾矿混凝土的损伤特性。将制备的铁尾矿混凝土在5%(质量分数,下同)的Na_(2)SO_(4)溶液中进行冻融循环试验,分析质量损失、相对动弹性模量和抗压强度损失的变化规律;结合损伤力学,以超声波波速为损伤变量,研究耦合作用下铁尾矿混凝土的劣化过程,并通过分析超声波速、弹性模量与孔隙率的关系,构建了铁尾矿混凝土密实度模型。结果表明:铁尾矿混凝土的质量在循环20次时出现阶段性增长,随后呈递减趋势,相对动弹性模量和抗压强度的下降速率呈先快、后慢、再快的现象;抗压强度损失与混凝土损伤度呈正相关,超声波速、弹性模量与孔隙率呈反比;在冻融循环和硫酸盐侵蚀耦合作用下,铁尾矿混凝土的劣化速率最快。研究结果可为铁尾矿混凝土在复杂寒冷环境下的应用提供参考价值。In order to clarify the durability of iron tailings concrete under complex environment,the damage characteristics of iron tailings concrete under the coupling action of freeze-thaw cycle and sulfate erosion were studied.A freeze-thaw cycle test was carried out on the prepared iron tailings aggregate concrete in 5%(mass fraction,the same below)Na_(2)SO_(4)solution to analyze the changes of mass loss,relative dynamic elastic modulus and compressive strength loss.Combined with damage mechanics,the degradation process of iron tailings concrete under coupling action was studied with ultrasonic wave velocity as damage variable,and a compacted model of iron tailings concrete was established by analyzing the relationship between ultrasonic wave velocity,elastic modulus and porosity.The results indicate that the mass of iron tailings concrete shows a phased increase after 20 cycles,followed by a decreasing trend.The relative dynamic elastic modulus and compressive strength decrease at first fast,then slow and then fast.Compressive strength loss is positively correlated with concrete damage degree,and ultrasonic wave velocity,elastic modulus and porosity are inversely proportional.Under the coupling action of freeze-thaw cycle and sulfate erosion,the deterioration rate of iron tailings concrete is the fastest.This study can provide reference value for the application of iron tailings concrete in complex cold environment.

关 键 词：非金属建筑材料 铁尾矿混凝土 冻融循环 硫酸盐侵蚀 耐久性能 密实度模型 

分 类 号：TU528[建筑科学—建筑技术科学] TD981[矿业工程—选矿]