纳米SiO_(2)对硫铝酸盐混凝土负温力学性能与微观结构的影响  

Effect of nano-SiO_(2)on negative temperature mechanical properties and microstructure of sulfoaluminate concrete

作　　者：李恒 王正君[1,2] 杜英欣[3] LI Heng;WANG Zhengjun;DU Yingxin(College of Water Resources and Electric Power,Heilongjiang University,Harbin 150080,China;Key Laboratory of Cold Region Hydraulic Engineering,Heilongjiang University,Harbin 150080,China;Heilongjiang Heidai Water Conservancy Engineering Quality Inspection Co.,Ltd.,Harbin 150040,China)

机构地区：[1]黑龙江大学水利电力学院,哈尔滨150080 [2]黑龙江大学寒区水利工程重点实验室,哈尔滨150080 [3]黑龙江黑大水利工程质量检测有限公司,哈尔滨150040

出　　处：《复合材料学报》2025年第3期1555-1565,共11页Acta Materiae Compositae Sinica

基　　金：黑龙江省重点研发计划指导类科研项目(GZ20220138);黑龙江省生态环境厅科研项目(HST2022GF004)。

摘　　要：为保证混凝土在负温环境下的安全可靠,采用力学性能测试、超声波波速测试、扫描电子显微镜(SEM)、X射线衍射(XRD)结合Rietveld精修定量分析等方法,研究了恒负温(-10℃)养护条件下不同纳米SiO_(2)(NS)掺量对硫铝酸盐混凝土性能的影响。结果表明:硫铝酸盐混凝土强度随NS掺量的增加,先升高后降低,在2wt%NS掺量时强度达到最大;当养护温度从负温变为常温时,超声波波速先降低后升高,掺入NS后再次水化(升高段)的超声波波速上升速率均高于空白组,其中2wt%NS掺量的混凝土超声波波速上升速率最快;SEM和XRD发现随NS掺量增加,混凝土内部孔隙结构变得更加致密,钙矾石(AFt)相对含量逐渐上升,其中2wt%NS掺量AFt含量最高,说明NS可以促进负温环境下的硫铝酸盐混凝土的水化。To ensure the safety and reliability of concrete in a negative temperature environment,mechanical property testing,ultrasonic wave velocity testing,scanning electron microscopy(SEM),and X-ray diffraction(XRD)combined with Rietveld refinement quantitative analysis and other methods were used to study the properties of sulfoaluminate concrete modified with different nanosized SiO_(2)(NS)admixtures under constant negative temperature(−10℃)curing conditions.The results show that the strength of sulfoaluminate concrete increases and then decreases with the increase of NS dosage and reaches the maximum strength at 2wt%NS dosage;When the curing temperature changes from negative temperature to room temperature,the ultrasonic wave velocity first decreases and then increases,and the ultrasonic wave velocity increase rate of rehydration(elevated section)after mixing NS is higher than that of the blank group,in which the ultrasonic wave velocity increase rate of the concrete with 2wt%NS admixture is the fastest;SEM and XRD found that with the increase of NS dosage,the internal pore structure of concrete becomes denser,and the relative content of calcium alumina(AFt)rises gradually,the 2wt%NS admixture AFt content is the highest,indicating that NS can promote the hydration of sulfoaluminate concrete under negative temperature environment.

关 键 词：硫铝酸盐水泥 纳米SiO_(2) 超声波波速 力学性能 微观结构 

分 类 号：TB332[一般工业技术—材料科学与工程] TU528.3[建筑科学—建筑技术科学]