ABSTRACT

Carbonation-induced corrosion limits the durability of reinforced concrete structures exposed in urban environments. In these exposure conditions, the propagation phase of corrosion can be an important part of the service life and, hence the knowledge of the corrosion rate is essential for the design. However, data regarding the corrosion rate in carbonated concrete are scarce and mainly refer to Portland cement concrete. This paper reports the corrosion rate and corrosion potential of steel bars embedded in concretes with different binders and water/binder ratios, exposed both outdoor in unsheltered conditions and in laboratory conditions characterised by different temperatures and relative humidities. Concrete resistivity at different depths is also reported and correlations among these parameters are discussed. Corrosion potential, corrosion rate and concrete resistivity were strongly influenced by the relative humidity, while temperature played an important role only at high relative humidity. Steel in Portland cement concrete showed the lowest corrosion rate.

摘要

碳化引起的腐蚀限制了暴露在城市环境中的钢筋混凝土结构的耐久性。在这些暴露条件下，腐蚀的传播阶段可能是使用寿命的重要组成部分，因此腐蚀速率的知识对于设计至关重要。然而，关于碳酸盐混凝土腐蚀率的数据很少，主要是指硅酸盐水泥混凝土。本文报告了嵌入在具有不同粘合剂和水/粘合剂比率的混凝土中的钢筋的腐蚀速率和腐蚀潜力，这些钢筋暴露在室外无遮蔽条件下和以不同温度和相对湿度为特征的实验室条件下。还报告了不同深度的混凝土电阻率，并讨论了这些参数之间的相关性。腐蚀潜力，腐蚀速率和混凝土电阻率受相对湿度的影响很大，而温度仅在高相对湿度下才起重要作用。硅酸盐水泥混凝土中的钢显示出最低的腐蚀率。