Construction World December 2022

CIVIL ENGINEERING CONTRACTORS

REHABILITATION OF OMARURU BRIDGE – HENTIES BAY, NAMIBIA

T he upgrading and rehabilitating of the Omaruru River Bridge stemmed from the project to upgrade the salt road between Swakopmund and Henties Bay (MR44) to a bituminous paved road. The route forms an important link from the inland communities to the coast. First constructed in 1980, the bridge is a vital structure on the route but, after a mere 12 years, it required comprehensive concrete repairs due to severe concrete damage to the structure. A further 23 years later, in 2015, the bridge was found to have deteriorated again to an extent that greatly compromised its structural integrity. The deterioration of the Omaruru River Bridge was predominantly the result of the harsh local conditions. Located approximately 2 km from the Atlantic Ocean its poor condition can be attributed to the extremely harsh environmental conditions impacting the bridge. The climate in this area varies from very warm and dry (when the wind blows from the inland of Namibia) to wet, misty and very cold, virtually marine conditions (when the wind blows from the ocean). This results in temperatures ranging from 0°C to 45°C, among the harshest ranges on the planet. In addition to these environmental conditions, the approach road was a salt road, which had been sprayed daily with concentrated salt water. The combination of the harsh

PROJECT INFORMATION

• Company entering: Zutari • Client: Roads Authority of Namibia • Start date: 2015 (design) and 2019 (construction) • End date: October 2021 • Main Contractor: Roads Contractor Company • Project Manager: Zutari/Bicon

• Consulting Engineer: Zutari/Bicon • Subconsultant: W Louw & Associates • Subconstructor: Zhongmei Engineering

environment and salt ingress into the structure created ideal circumstances for the inevitable chloride corrosion of the steel reinforcement and weakening of the concrete. Roads Authority of Namibia instigated a project to resolve the bridge issue and appointed Zutari, in joint venture with Bicon Namibia for the detailed design, tender documentation, contract management and site supervision services, with Zutari assigned responsibility for the bridge work. 

24 21 st Best Project Awards 2022