盐渍土地区复杂环境下混凝土中SO42-的传输规律研究
Study on the transport law of SO42- in concrete under saline soil area complex environment
关键词:
硫酸盐侵蚀-干湿-高低温-冻融循环;混凝土;水胶比;玄武岩纤维;SO42-;扩散系数
Key words:
Sulfate erosion-dry-wet-high-low temperature freeze-thaw cycle; Concrete; Water-binder ratio; Basalt fiber; SO42-; Diffusion coefficient
刊期:
2025年第11期
DOI:
10.19761/j.1000-4637.2025.11.026.06
文章编号:
基金项目:
国家自然科学基金项目(51308445)。
作者:
丁 骥1,宋海奎2
单位:
1.中国路桥工程有限责任公司,北京 100011;2.三门峡市昌通路桥建设有限责任公司, 河南 三门峡 472099
摘要
摘 要:为了探究盐渍土环境下硫酸盐侵蚀-干湿-高低温-冻融循环作用对混凝土中SO42-传输的影响,通过室内加速试验模拟了盐渍土环境,研究了多种因素循环作用下水胶比和玄武岩纤维掺量对混凝土中SO42-浓度的影响,并基于Fick第二定律建立了SO42-扩散系数时变模型。结果表明:试件相同深度处的SO42-浓度随着循环次数的增加而基本增加;随着深度的增加,SO42-浓度基本先降低后趋于稳定;随着循环次数的增加,SO42-侵蚀深度基本增加;在相同循环次数下,随着水胶比的降低,SO42-浓度降低;随着纤维掺量的增加,SO42-浓度基本呈先降低后增加的趋势;所建立的多种因素循环作用下混凝土的SO42-扩散系数时变模型精度较高。
Abstract: In order to investigate the transport law of SO42- in concrete under the conditions of sulfate erosion-dry-wet-high-low temperature-freeze-thaw cycle in saline soil environment, the saline soil environment was simulated by indoor accelerated test to study the effects of the water-binder ratio and basalt fiber content on the concentration of SO42- in concrete under the variety cycles effects, and a time-varying model of SO42- diffusion coefficient was established based on Fick’s second law. The results show that the sulfate ion concentration at the same depth of the specimen basically increases with the increase of the number of cycles. With the increase of the depth, the SO42- concentration basically decreases firstly and then tends to be stabilized. With the increase of the number of cycles, the depth of SO42- erosion basically increases. Under the same number of cycles, with the decrease of the water-binder ratio, the concentration of SO42- decreases. With the increase of the fiber content, the SO42- concentration basically shows the trend of first decreasing and then increasing. The established time-varying model of SO42- diffusion coefficient of concrete under the action of variety cycles has high accuracy.
结论
(1)混凝土试件相同深度处的SO42-浓度随着循环次数的增加而基本增加;随着深度的增加,SO42-浓度基本先降低后趋于稳定;随着循环次数的增加,SO42-侵蚀深度基本增加。
(2)相同循环次数下,随着水胶比的降低,SO42-浓度降低,随着纤维掺量的增加,SO42-浓度基本呈先降低后增加的趋势。
(3)多种循环作用下,混凝土的SO42-扩散系数随侵蚀时间的增加而减小。
(4)本文所建立的多种循环作用下混凝土的SO42-扩散系数时变模型精度较高,试验结果与模型计算结果基本一致,能用于盐渍土地区混凝土SO42-扩散系数的预测及耐久性能研究。
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引用本文
丁骥,宋海奎.盐渍土地区复杂环境下混凝土中SO42-的传输规律研究[J].混凝土与水泥制品,2025(11):26-31.
DING J, SONG H K.Study on the transport law of SO42- in concrete under saline soil area complex environment[J].China Concrete and Cement Products,2025(11):26-31.
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