A full range of spray equipment from Graco was used for waterproofing and resurfacing work on the Sydney Harbour Bridge.
Listed in the Guinness Book of Records as the world’s widest long-span bridge, the bridge is 1149 metres in length and has more than 160,000 vehicles crossing over each day.
After 80 years, the Sydney Harbour Bridge required essential waterproofing and resurfacing work for which the original concrete deck was stripped for essential maintenance. The purpose of the resurfacing and waterproofing was to create a smoother, more durable road surface, reduce road noise, lower risk of corrosion and structural damage on the bridge deck, and rejuvenate the bridge. Waterproofing the bridge deck would minimise the need for future repairs.
Three Graco XP70 plural component sprayers and four Graco Reactor H-XP3 hydraulic proportioners were used for adhesive and polyurethane spray. Everything was set up on trucks including material, generators, compressors and Graco equipment. The trucks travelled down one lane while spraying the adjacent lane. A three-layer polyurethane waterproofing system was applied to the concrete deck of the north and south approach spans.
Heated crumbed rubber bitumen was sprayed onto the concrete deck of the arch span to provide a waterproofing seal. Aggregate was then spread over and rolled into the spray seal with the excess aggregate swept up and removed. Following the waterproofing, the construction team applied the asphalt and made the pavement.
Essential bridge maintenance work was completed over the weekends of 13-16 and 20-23 January 2012. In spite of the rain, the construction team managed to complete the waterproofing and resurfacing 10 hours ahead of schedule.