Investigating the Influence of Site Soil and Water Chemistry on Durability of Precast Concrete Culverts

Precast concrete culverts are commonly used as an essential part of the road network of a country. However, frequent site inspections, repair, and replacement of culverts in the remote area require road closure, high cost, and logistical challenges. Thus, a comprehensive understanding of the exposure conditions is essential to manufacture durable reinforced concrete culverts, especially for remote country regions. This paper investigates the influence of exposure conditions on the durability of precast reinforced concrete culverts by inspecting 14 selected culverts showing deterioration in the remote Wheatbelt Region of Western Australia. Soil and water samples collected from the sites were analyzed in the laboratory, and the results were used to assess the level of damage observed in the culverts during site inspection. The results revealed that 85% of the inspected culverts were situated in highly saline soil, and 65% of the deteriorated culverts were exposed to an environment rich in magnesium sulphate and chloride. In total, 9 out of 14 inspected sites were classified as exposure C under AS 5100.5. Overall, the investigation assessed the deterioration of culverts considering the influence of soil and water chemistry, offering a realistic perspective on culvert deteriorations and providing valuable insights for developing sustainable infrastructure in this regional context. The findings establish a baseline for enhancing the corrosion resistance of precast culverts and emphasize the importance of considering high salinity as a critical parameter for durability design.