环境因素对江苏沿海输变电钢筋混凝土的劣化机制分析

Analysis of environmental factors on deterioration mechanism of reinforced concrete in coastal area of Jiangsu

为探明不同环境因素与侵蚀介质对江苏沿海地区输变电钢筋混凝土构件的腐蚀程度影响规律,分析防腐蚀措施的必要性与不同措施的防腐效果,对江苏省沿海地区典型用地类型中强度等级C30的钢筋混凝土构件及周围水土样本进行取样分析。采用回弹法测试混凝土构件的抗压强度并确定构件中性化深度,同时测定水体、土壤及混凝土样品中Cl^(-)与SO_(4)^(2-)浓度,分析环境因素及防腐措施对钢筋混凝土构件的侵蚀破坏影响规律。根据前期测试结果选取混凝土代表样,进行X射线衍射(XRD)分析,并基于XRD全谱拟合法定量混凝土样品的矿物成分,探明江苏沿海钢筋混凝土构件的腐蚀劣化机制。结果表明:当环境作用等级达到严重及以上时,钢筋混凝土构件将受到由Cl^(-)侵蚀主导的中性化破坏,中性化深度可达40 mm,同时中性化过程将加剧腐蚀性离子对钢筋混凝土的侵蚀,使构件强度损失达到9.7%~28.3%;采取涂刷防护涂层或施用高性能耐蚀混凝土等防腐措施将显著改善混凝土构件的抗腐蚀性能。

To explore the influence of different environmental factors and erosion media on the corrosion degree of power transmission and transformation reinforced concrete members in coastal areas of Jiangsu Province,analyze the necessity of anticorrosion measures and the effect of different anticorrosion measures,samples of reinforced concrete members and surrounding soil and water in typical coastal areas of Jiangsu Province are sampled and analyzed.At the same time,the concentrations of Cl^(-)and SO_(4)^(2-)in water,soil and concrete samples are measured.The influencelaw of environmental factors and anti-corrosion measures on the erosion and destruction of reinforced concrete members is analyzed.According to the preliminary test results,representative concrete samples are selected for X-ray diffraction(XRD)analysis,and the mineral composition of concrete samples is quantified based on the full spectrum fitting method of XRD,so as to explore the corrosion and deterioration mechanism of reinforced concrete components in coastal area.The results show that when the level of environmental action is serious or above,the reinforced concrete members will be subjected to the neutral damage led by Cl^(-)erosion,and the neutral process will aggravate the erosion of corrosive ions on reinforced concrete(the neutral depth can reach 40 mm),and the strength loss of component can reach 9.7%~28.3%.The corrosion resistance of concrete components can be improved significantly by applying protective coating or high performance corrosion resistant concrete.