混凝土强度对混凝土中钢筋腐蚀的影响

Effect of concrete strength on reinforcement corrosion in concrete

混凝土保护钢筋不被腐蚀。人们普遍认为钢筋混凝土中钢筋的腐蚀随混凝土强度变化。为研究钢筋腐蚀率随混凝土强度的变化规律,通过浇筑20个钢筋混凝土试件,养护至4种不同龄期后将钢筋腐蚀相同的时间。电解液腐蚀方法用于诱导腐蚀以便加快腐蚀速度。钢筋的理论腐蚀量根据法拉第定律计算,实际腐蚀率根据钢筋腐蚀前后的重量损失计算。试验数据显示当混凝土强度为23～35MPa时,钢筋腐蚀率随混凝土强度增大有下降趋势,但混凝土强度为27～30MPa时,钢筋腐蚀率反而随混凝土强度增大而升高。

Concrete normally provides a high degree of protection to the reinforcing steel against corrosion.It has been commonly assumed that steel corrosion in concrete is affected by concrete strength.In order to investigate the effect of concrete strength on corrosion of reinforcing steel, 20 reinforcing steel bars cast in concrete were cured for 4 different ages while the embedded steels corroded to the same time thereafter.Electrolyte corrosion technique was used to induce corrosion of steels in concrete in order to accelerate the corrosion process.The theoretical corrosion amount was calculated based on Faraday＇s law.The actual corrosion level was measured by the mass loss of steel after corroding.It was demonstrated that corrosion level generally tended to decrease with the concrete strength 23 to 35MPa,with an exception for a strength value from 27 to 30MPa, where the corrosion level increased with concrete strength.