Civil Engineering March 2022 | Vol 30 No 2

26 March 2022 Civil Engineering A visual inspection of the Omaruru River Bridge revealed that the pier col- umns and abutments were in good condi- tion overall and that there was only minor spalling in some areas. However, sections of the concrete deck and pier heads had deteriorated where water concentrated on the deck and ultimately flowed over concrete elements. The following notable defects were identified during the visual inspection: Q Q Spalled concrete at the ends of the pier and abutment seating beams as a result of water leaking through deck joints (see Figures 3 and 4) Q Q Parapets in poor condition due to the corrosion of reinforcement (see Figure 5) Q Q Spalled concrete at the inside faces of the end beams due to blocked drainage holes (see Figure 6) Q Q Spalling and reinforcement corrosion at the concrete faces near joints due to water leaking from the deck (see Figure 7). CONCRETE INVESTIGATIONS Zutari appointed W-Louw & Associates as a subconsultant to help conduct detailed concrete investigations, including non-destructive testing, carbonation testing, chloride testing and determining the concrete’s compressive strength. The results from the concrete Figure 1 Photo from the top of the bridge, downstream towards the Atlantic Ocean Figure 2 Cross section of the original bridge deck Figure 3 Spalled concrete at end of pier seating beam Figure 4 Spalled concrete at abutment seating