Extended evaluation of durability-related field inspection data from concrete bridges under service

摘要

The paper continues and extends the assessments of the degradation level of reinforced concrete bridges under service in the Czech Republic. The evaluation is based on the in-situ measurements that were performed on the bridges belonging to main roads and motorways. The combined effect of aggressive agents (carbonation and chlorides) related to the risk of corrosion of steel reinforcement was evaluated on drilled concrete core samples. The ratio between the concentrations of Cl~- and OH~- was evaluated based on the ratio of water-soluble chloride content and pH. All the data were summarized in a statistical manner, and the relationships among resulting data were provided. The main goal of this study is to extend the number of investigated bridges from five bridges to fourteen; the published results from already evaluated highway bridges are complemented by four more main road bridges and five motorway bridges. The focus is given to the non-proportional influence of the chloride content per mass of concrete on the reinforcement corrosion and to localization of the "critical" parts of the bridges affected by corrosion-related degradation.