Garth Prowd Bridge
Project Background
The Garth Prowd Bridge was constructed circa 1972 and is located on Noosa Parade, Noosa Heads. The four-span pre-stressed deck unit bridge is radially super-elevated and consists of two traffic lanes and a pedestrian walkway on both the northern and southern sides.
The deck is transversely post-tensioned, and the anchorages are hidden on each side of the bridge by the cast in-situ kerbs. Each of the RC abutment and pier headstocks is supported by 6 no. square prestressed piles.
The Problem
The bridge was generally in good condition; however, water ingress through the bridge deck caused corrosion to the underside concrete elements.
Elevated levels of chloride were found in sections of the concrete girders, and corrosion protection was considered necessary to extend the bridge's service life.
Our Solution
Marine and Civil Maintenance installed ninety, 1m Galvashield® SM-DAS-X galvanic anodes after the system was selected to protect concrete girders with high chlorides, as shown from the condition assessments. Marine & Civil Maintenance based their design on this option due to ease of installation and the ability to install the system without breaking the pre-stressed strands.
Originally, Osborne Consulting specified this project as a two-stage anode specification but was changed to a surface-mounted galvanic anode option due to the ease of application. Other works included spalling repairs, bridge deck waterproofing, pile jacket remediation, replacement of the walkway, and painting of steel balustrades as part of the bridge upgrade.
Technology Used
These innovative products and technologies were used on this project.