Civil Engineering March 2022 | Vol 30 No 2

Civil Engineering March 2022 25 T he design to upgrade the salt road between Swakopmund and Henties Bay in Namibia to a bituminous paved road began in 2015. Investigations for the design revealed that the Omaruru River Bridge on this route had suffered severe concrete damage. The damage was a result of the harsh environmental condi- tions in the area and salt water sprayed on the approach roads. This harsh environment created ideal circumstances for rapid chloride ingress and the inevitable corrosion of the steel reinforcement. The Omaruru River Bridge is located approximately 5 km from the coast. The climate varies from very warm and dry (when wind blows from the inland of Namibia) to wet, misty and very cold (when wind blows from the Atlantic Ocean). The approach road is a salt road, which had to be sprayed with salt water daily. The bridge was constructed in 1980, and in 1992, merely 12 years later, comprehen- sive concrete repairs had to be performed. Over the following 23 years, the bridge deteriorated even further to the extent that its integrity was severely compromised. Repairing the Omaruru River Bridge on the road between Henties Bay and Uis formed part of a larger project for the Roads Authority of Namibia to upgrade the following roads in the Erongo Region to bitumen standards: Q Q MR44: Swakopmund to Henties Bay Q Q MR76: Henties Bay to Uis to Kamanjab. Bicon and Zutari were appointed as a joint venture for the detailed design, tender documentation, contract management and site supervision services of this project. The key question was whether it would be possible to repair the bridge sustainably. A holistic approach was fol- lowed to find a solution that would create an enduring structure and maintain and improve the main access route for the communities around the area. ASSESSMENT OF ORIGINAL BRIDGE The original bridge was 11 m wide. It consisted of two road lanes, each 3.7 m wide, two shoulders, each 1.2 m wide, and NJ-type parapets on either side of the bridge, each 0.6 m wide (see Figure 2). Sachin Ravjee Bridge Engineer Zutari sachin.ravjee@zutari.com Johan Kotzé Pr Eng Technical Director, Civil Structures Lead Zutari jckotze@zutari.com Paul Mavundla Bridge Engineer Zutari paul.mavundla@zutari.com Omaruru River Bridge: repairing severely deteriorated infrastructure When the Omaruru River Bridge deteriorated to the extent that its integrity was severely compromised, a solution had to be found to restore the bridge and reduce water ingress through the deck to combat the location’s extremely harsh environmental conditions. The Omaruru River Bridge