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颜世忠1 , 施振跃2

 

( 1. 济宁高新区王因街道办事处 , 济宁   272103 ;  2.  山东科技大学 资源学院 ,  泰安    271019)

摘  要 :  为揭示冻融-硫酸盐侵蚀双重作用下水工复掺混凝土的性能劣化规律 ,  以粉煤灰 、硅灰 、片麻岩石粉为矿物掺合料 , 通过室内试验系统研究了不同掺合料配比 、硫酸盐溶液浓度  ( 0 、5% 、10% 、15%)  及冻融循环温度  ( -5 ~ 25 、-20 ~ 25 、- 35 ~ 25 ℃ )  下混凝土的质量损失率 、抗压强度 、相对动弹性模量及气体渗透性演变特征 。结果表明 : 混凝土质量损失率与冻融循环次数 、硫酸盐浓度呈正相关 ,  与冻结温度呈负相关 。抗压强度和相对动弹性模量随冻融循环次数增加 、硫酸盐浓度升高及冻结温度降低而显著衰减 , 硫酸盐溶液浓度为15% 、- 35 ~ 25 ℃ 冻融环境下劣化最为严重 ; 气体渗透系数增长率在前 40 次冻融循环中占总增长率的 85. 1% ,密实性破坏集中于该阶段 ; 矿物掺合料配比对混凝土抗侵蚀性能影响显著 , 粉煤灰-硅灰配比 1 : 1 时协同效应最优 , 而粉煤灰-硅灰-片麻岩石粉三掺体系  ( 1 : 1 : 1)  通过优化孔隙结构 , 展现出更优的抗冻融-硫酸盐侵蚀能力 , 其质量损失率仅为 2. 1% ~ 3. 5% 。研究成果可为相关工程提供参考。

关键词 : 水工复掺混凝土 ; 盐冻耦合 ; 性能劣化试验 ; 复掺配合比 ; 劣化机理

中图分类号 : TU528           文献标志码 : A           文章编号 :  1005- 8249  (2026)  03-0001-06

DOI :10. 19860/j. cnki. issn1005- 8249. 2026. 03. 001

YAN Shizhong1 , SHI Zhenyue2

( 1. Wangyin Subdistrict Office Ji ’ning High-Tech Zone , Ji ’ning 272103 ,  China;

2. College of Resources , Shandong University of Science and Technology ,  Tai ’an 271019 ,  China)

Abstract :  To elucidate  the  degradation  patterns  of  hydraulic  concrete  with  multiple  admixtures  under  dual  freeze - thaw  and sulphate erosion effects , a systematic laboratory investigation was conducted using fly ash , silica fume , and gneiss rock powder as mineral  admixtures. The study examined  the evolution of  concrete mass loss rate , compressive strength , relative elastic modulus , and gas permeability under varying admixture ratios , sulphate solution concentrations  ( 0 ,  5% ,  10% ,  15%) ,  and freeze-thaw cycle temperatures  ( - 5 ~ 25 ,  - 20 ~ 25 ,  - 35 ~ 25  ℃ ) . Results  indicate  that  concrete  mass  loss  rate  exhibits  a positive correlation with freeze-thaw cycle count and sulphate concentration , while showing a negative correlation with freezing temperature. Compressive  strength  and  relative  elastic  modulus  significantly  deteriorated  with  increasing  freeze - thaw  cycles , rising sulphate concentration , and decreasing freezing temperature. The most severe degradation occurred at a  sulphate solution concentration of 15% under a  - 35 ~ 25  ℃  freeze - thaw  environment.  The  gas  permeability  coefficient  increase  accounted  for 85. 1% of the total increase within the first 40 freeze - thaw cycles , with density degradation concentrated in this phase. The mineral admixture ratio significantly influenced concrete's erosion resistance. The optimal synergistic effect was achieved with a fly ash-silica fume ratio of 1 :  1. The ternary admixture system  (fly ash-silica fume-gneiss powder at  1 :  1 :  1)  demonstrated superior freeze-thaw and sulphate erosion resistance by optimising pore structure , exhibiting a mass loss rate of merely 2. 1% - 3. 5% . The research findings can provide reference for relevant engineering projects.

Key words :  hydraulic concrete with multiple admixtures;  salt-freeze coupling; performance degradation testing; multipleadmixture mix design; degradation mechanism