融雪剂和冻融耦合作用下纳米二氧化硅混凝土损伤试验研究  

Experimental study on nano-silica concrete damage under coupling effect of snow melting agent and freeze-thaw cycle

作　　者：宋宁 胡裕成 景宏君 郭美蓉 单俊伟 SONG Ning;HU Yucheng;JING Hongjun;GUO Meirong;SHAN Junwei(Highway Bureau of Ankang,Ankang,Shaanxi 725000,China;School of Civil and Architectural Engineering,Xi’an University of Science and Technology,Xi’an,Shaanxi 710054,China;Road Engineering Research Center,Xi’an University of Science and Technology,Xi’an,Shaanxi 710054,China)

机构地区：[1]安康市公路局,陕西安康725000 [2]西安科技大学建筑与土木工程学院,陕西西安710054 [3]西安科技大学道路工程研究中心,陕西西安710054

出　　处：《公路交通科技》2025年第3期87-94,146,共9页Journal of Highway and Transportation Research and Development

基　　金：陕西省交通运输厅科研项目(24-16K)。

摘　　要：【目标】研究公路工程冬季撒布融雪剂导致混凝土结构寿命缩减的问题。【方法】通过掺入纳米二氧化硅制备改性混凝土,设计5组纳米二氧化硅掺量(0,0.5%,1.0%,1.5%,2.0%)采用快冻法模拟冻融循环,配合3%氯盐类融雪剂溶液构建侵蚀-冻融耦合环境。通过表观形貌、质量损失率、相对动弹性模量评价宏观性能,结合核磁共振技术从微观角度揭示孔隙结构演变规律和作用机制。【结果】随着冻融循环次数增加,各组混凝土试件均出现不同程度的砂浆脱落、坑蚀和骨料外漏现象。二氧化硅掺入量为0,0.5%,1.5%,2.0%的混凝土质量损失率与冻融循环次数呈正相关,二氧化硅掺入量为1.0%的混凝土质量损失率出现负增长。相对动弹性模量随冻融次数增加而降低。纳米二氧化硅的掺入显著改善了混凝土的表观形貌、质量损失率和相对动弹性模量,改变了混凝土的孔隙结构分布,不同孔隙类型的积分面积随着纳米二氧化硅的掺量呈先减后增趋势。纳米二氧化硅掺入量为1.0%的混凝土质量损失率增长较缓,相对动弹性模量下降速率较慢,孔隙结构转化速率较低,表现出优异的抗侵蚀效果。【结论】研究成果为提升寒区交通基础设施的耐久性提供了全新的材料解决方案,对于延长混凝土结构的使用寿命、降低养护成本具有重要的工程应用价值。[Objective]The study addresses the issue of concrete structure service life decreasing caused by the snow melting agent spreading during highway engineering in winter.[Method]The nano-silica-modified concrete was designed with various nano-silica contents of 0,0.5%,1.0%,1.5%,2.0%.The freeze-thaw cycle was simulated by using the rapid freezing method.3%chlorine salt snow melting agent solution was conducted to establish an erosion-freeze-thaw coupling environment.The macroscopic performance was evaluated through apparent morphology,mass loss rate,and relative dynamic elastic modulus;while the nuclear magnetic resonance technology was employed to microscopically analyze the pore structure evolution.[Result]With freeze-thaw cycles increasing,all concrete specimens exhibit varying degrees of mortar spalling,pitting,and aggregate exposure.The concrete mass loss rates,with nano-silica contents of 0,0.5%,1.5%,2.0%,show the positive correlations with freeze-thaw cycles,whereas that with 1.0%exhibits the negative.The relative dynamic elastic modulus decreases with the prolonged freeze-thaw cycles.The nano-silica incorporation significantly improves the apparent morphology,mass loss rate,and relative dynamic elastic modulus.The concrete pore structure distribution is optimized.The integral areas with different pore types first decrease,and then increase with nano-silica contents.The mass loss rate of concrete with 1.0%nano-silica content grows slowly.The relative dynamic elastic modulus decreases at a slower rate.The pore structure conversion rate is low,indicating the superior erosion resistance.[Conclusion]The study provides a novel material-based solution to enhance the transportation infrastructure durability in cold regions,offering the significant engineering value for prolonging concrete service life and reducing maintenance cost.

关 键 词：道路工程 融雪剂 冻融循环 纳米混凝土 孔隙结构 

分 类 号：U414[交通运输工程—道路与铁道工程]