Concrete in maritime structure is vulnerable to deterioration owing to external sulphate attack, which can be exacerbated by wetting-drying action (WDA), jeopardizing its resistance to cyclic loads such as wind, wave and earthquake actions. This study aims to investigate the compressive fatigue behavior of concrete exposed to sulphate attack and WDA in marine environment. Cyclic compressive loading test was conducted on concrete after 150 days of deterioration. The effects of sulphate attack and WDA, upper stress loading level and loading frequency on fatigue life, residual strain, variation of elastic modulus and post-cyclic compressive strength were investigated. The sulphate penetration profiles, volume change and mass change of concrete during the exposure time were also measured. In addition, the performance of limestone concrete and SiMn slag concrete was compared in the study. The sulphate ion was found to penetrate concrete up to a depth of 20 mm, with a maximum content of 1.72%–2.58% near the surface. The cyclic loading test showed that degraded concrete had 38.2% higher residual displacement and 1.4% lower modulus of elasticity than normal concrete. The sulphate attack and WDA weakened the concrete, reducing its fatigue resistance. SiMn slag concrete had a lower fatigue life, larger residual displacement and greater stiffness degradation than limestone concrete.

由于外部硫酸盐侵蚀，海事结构中的混凝土容易变质，干湿作用 (WDA) 会加剧这种情况，危及其对风、波浪和地震作用等循环载荷的抵抗力。本研究旨在研究暴露于硫酸盐侵蚀和 WDA 在海洋环境中的混凝土的压缩疲劳行为。对劣化 150 天后的混凝土进行循环压缩载荷试验。研究了硫酸盐侵蚀和 WDA、上应力加载水平和加载频率对疲劳寿命、残余应变、弹性模量变化和循环后压缩强度的影响。还测量了暴露时间期间混凝土的硫酸盐渗透曲线、体积变化和质量变化。此外，研究比较了石灰石混凝土和硅锰矿渣混凝土的性能。发现硫酸根离子可穿透混凝土达 20 毫米的深度，在表面附近的最大含量为 1.72%–2.58%。循环荷载试验表明，退化混凝土的残余位移比普通混凝土高 38.2%，弹性模量低 1.4%。硫酸盐侵蚀和 WDA 削弱了混凝土，降低了其抗疲劳性。与石灰石混凝土相比，硅锰矿渣混凝土具有较低的疲劳寿命、较大的残余位移和较大的刚度退化。弹性模量比普通混凝土低 4%。硫酸盐侵蚀和 WDA 削弱了混凝土，降低了其抗疲劳性。与石灰石混凝土相比，硅锰矿渣混凝土具有较低的疲劳寿命、较大的残余位移和较大的刚度退化。弹性模量比普通混凝土低 4%。硫酸盐侵蚀和 WDA 削弱了混凝土，降低了其抗疲劳性。与石灰石混凝土相比，硅锰矿渣混凝土具有更低的疲劳寿命、更大的残余位移和更大的刚度退化。