Condition rating for maintenance of existing reinforced concrete bridges in Soweto, South Africa

Reinforced concrete (RC) bridges are key highway structures of national importance to any country's economy. In developing countries such as South Africa, these structures are not adequately maintained. The purpose of this paper was to obtain inventory and inspection data from the various road agencies and analyze the relationships that exist on the inspected bridges. The data was obtained from bridges in Soweto, South Africa. The analysis involved the following: determining the predominant defects and presenting their relationships with inventory data such as bridge age. STATA logit models were used to investigate whether the relationships were statistically significant. Furthermore, the condition indices (average structure condition index and priority condition index) were also investigated to assess the condition of the bridge structures. Cracking and spalling were the predominant defects and were distributed mostly on abutments and deck slabs of RC bridges in Soweto. There were no statistically significant relationships identified between the predominant defects and age. However, there was a general decrease in condition indices with an increase in age. The average structure condition index of the RC bridges indicated that their conditions were fair to good. The data collected from the various road agencies on bridges inspected in Soweto should have indicated that inspections were done every five years. However this was not the case and therefore limited the findings from the analysis. Ultimately, a delay to conduct timeous bridge inspections or repairs may lead to its premature replacement or permanent closure before reaching its service life. Further studies should be undertaken on the severity of these defects.