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柏延平¹，马  雷¹，汪佐浩¹，李  瑞¹，雒亿平²

 

 

（1.国网甘肃省电力公司临夏供电公司，临夏 731100；

2.西安理工大学 西北旱区生态水利国家重点实验室，西安 710048）

摘要：为解决西北水利工程混凝土泛碱问题，通过干湿循环法开展加速泛碱试验，结合XRD、SEM、TG-DTG和1H NMR等多种微观检测技术，系统探究了泛碱现象的物质组成、微观特征、分布传输规律及孔隙结构演变机理。结果表明:混凝土泛碱主要产物有CaCO₃、Na₂SO₄、SiO₂和K₃Na(SO₄)₂等化合物以及其他少量盐类；经加速泛碱处理后，试件在200~500 ℃内的质量损失显著增加，Ca(OH)₂含量明显高于标准养护试件，且在0~2与8~10 mm深度区间内出现富集；加速泛碱试件的小孔占比变化较小，中孔占比降低77.99%，大孔占比增加19.75%，同时微裂缝占比提升10.27%，表明泛碱作用会导致混凝土孔隙率增大、孔隙分布劣化。研究成果为水利工程防护提供理论依据。

关键词：混凝土；泛碱性能；微观结构

中图分类号：TV431

文献标志码：A

文章编号：1005-8249（2025）06-0029-07

DOI：10.19860/j.cnki.issn1005-8249.2025-06-006

 

 

BAI Yanping¹,MA Lei¹,WANG Zuohao¹,LI Rui¹,LUO Yiping²

 

 

(1.State Grid Gansu Linxia Power Supply Company,Linxia 731100,China；2.State Key Laboratory

 

of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China)

 

Abstract：To investigate the efflorescence mechanism of concrete in water conservancy projects in Northwest China,accelerated tests were conducted using a wet-dry cycling method.The study comprehensively characterized the efflorescence phenomenon through multiple micro-analytical techniques,including X-ray diffraction (XRD),scanning electron microscopy (SEM),thermogravimetry-derivative thermogravimetry (TG-DTG),and proton nuclear magnetic resonance (1H NMR).Key findings are as follows:The main efflorescence products were identified as CaCO₃,Na₂SO₄,SiO₂,K₃Na(SO₄),and minor salts;After accelerated efflorescence treatment,concrete specimens showed significantly greater mass loss in the range of 200-500 ℃ and higher Ca(OH)₂ content compared to standard-cured specimens,with notable enrichment at depths of 0~2 and 8~10 mm;Efflorescence coarsened the pore structure:the proportion of mesopores decreased by 77.99%,while those of macropores and microcracks increased by 19.75% and 10.27%,respectively,with little change in micropore content.These results demonstrate that efflorescence increases concrete porosity and degrades the pore-size distribution,thereby adversely affecting the compactness and durability of the material.The research results provide a theoretical basis for the protection of water conservancy projects.

 

Key words：concrete;efflorescence performance;microstructure

基金项目：西北旱区生态水利国家重点实验室开放课题（XB15468）。

作者简介：柏延平（1994—），男，本科，高级工程师，研究方向:水工混凝土新材料。

通信作者：雒亿平（1984—），男，博士，教授，研究方向:水工混凝土新材料。

收稿日期：2025-03-10