浅谈沿海地区混凝土结构工程防腐关键技术

Talking about Key Anti-corrosion Technology of Concrete Structure Engineering in Coastal Area

海水中含有大量CO32–、Cl–、SO42–、HCO3–等酸根离子,其渗入混凝土中同水泥的水化产物发生反应,生成具有膨胀性的腐蚀产物,在混凝土内部产生应力,当其应力超过混凝土的抗拉强度时,混凝土局部发生开裂与剥落;酸根离子还能透过混凝土到达钢筋表面,破坏钢筋表面钝化膜而使钢筋锈蚀,铁转化成铁锈后,体积增加,致使混凝土保护层随钢筋膨胀而开裂、起鼓及剥落,钢筋完全失去保护并加快锈蚀速度,直接破坏混凝土结构强度和钢筋粘接性能,降低混凝土结构安全性、适用性、耐久性。因此,在沿海地区,做好混凝土结构的防腐工作非常重要。阐述沿海区域土建施工结构抗化学腐蚀相关施工工艺原理、特点及要求,为以后提高与改善沿海区域混凝土结构施工质量提供借鉴。

Seawater contains a large amount of acid radical ions such as CO32–、Cl–、SO42–、HCO3–,which penetrate into concrete and react with the hydration products of cement to generate expansive corrosion products,cause stress in the concrete.When the stress exceeds the tensile strength of concrete,the concrete will be partially cracked and peeled off. Acid ions can also pass through concrete to reach surface of the steel bar,destroy the passive film on the surface of the steel bar and cause the steel bar to corrode. After iron is transformed into rust,the volume increases,resulting in concrete protection the layer cracks,bulges and peels off with the expansion of the steel bar. The steel bar completely loses its protection and accelerates the corrosion rate,which directly destroys the strength of the concrete structure and the bonding performance of the steel bar,and reduces the safety,applicability and durability of the concrete structure. Therefore,in coastal areas,it is very important to do a good job of anti-corrosion of concrete structures. Based on understanding of chemical corrosion resistance construction technology of civil construction structures in coastal areas,this paper briefly explains the principles,characteristics and requirements of relevant construction technology to improve the construction quality of concrete structures in coastal areas.