This paper is to study the influence of sulphate corrosion on the mechanical behaviors of concrete, especially concrete corrosion under actual corrosion environment. This study investigated different immersion methods for concrete in a corrosion environment, and different strengths of concrete specimens with contents of sodium sulphate and magnesium chloride of 10.36% and 12.00%, respectively. Strength tests were performed on the specimens for the different immersion methods of full immersion, half‐immersion, and dry‐wet cycles, and with different strengths for the concrete of C20, C35, and C50. To study the internal mechanisms of the corrosion of concrete with different immersion methods and different strengths, a microscopic pore structure test was conducted. The field tests were performed after 12 years to evaluate the long term performance of the concrete under the actual environmental conditions. The test results show that full immersion mainly led to chemical corrosion, half immersion led to double damage from salt crystallization and chemical corrosion, and dry‐wet cycles accelerated the corrosions of the salt crystallization and chemical corrosion. The higher the strength of concrete, the better its resistance to the sulphate corrosion. In comparison with the strength of the concrete before corrosion, field test results show that the strength of uncorroded concrete after 12 years is increased by 9.5% and the strength of corroded concrete after 12 years is reduced by 56.2%. The results of the strength tests and pore structure tests show that sulphate has a significant impact on concrete strength after 12 years of field tests. This study will contribute to improve long‐term performance of the concrete, provide guidance for concrete structure design in corroded areas, and suggested that increasing attention should be paid to the effects of sulphate on concrete performance.

中文翻译：

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腐蚀环境下不同浸渍方法和不同强度混凝土的影响机理及长期现场试验验证

本文旨在研究硫酸盐腐蚀对混凝土力学性能的影响，特别是在实际腐蚀环境下的混凝土腐蚀。这项研究调查了在腐蚀环境下混凝土的不同浸渍方法，以及硫酸钠和氯化镁含量分别为10.36％和12.00％的混凝土试样的不同强度。在试样上进行了全浸，半浸和干湿循环的不同浸入方法的强度测试，并对C20，C35和C50的混凝土具有不同的强度。为了研究不同浸渍方法和强度对混凝土腐蚀的内部机理，进行了微观孔结构试验。12年后进行了现场测试，以评估混凝土在实际环境条件下的长期性能。测试结果表明，完全浸入主要导致化学腐蚀，半浸入导致盐结晶和化学腐蚀的双重破坏，而干湿循环加速了盐结晶和化学腐蚀的腐蚀。混凝土的强度越高，其抗硫酸盐腐蚀的能力越强。与腐蚀前的混凝土强度相比，现场测试结果表明，12年后未腐蚀的混凝土的强度提高了9.5％，而12年后未腐蚀的混凝土的强度降低了56.2％。强度测试和孔结构测试的结果表明，经过12年的现场测试，硫酸盐对混凝土的强度有重大影响。这项研究将有助于改善混凝土的长期性能，为腐蚀区域的混凝土结构设计提供指导，并建议应越来越重视硫酸盐对混凝土性能的影响。