New South Wales’ Richmond Valley Council sourced the asphalt from Blakebrook Quarry, which is owned by a neighbouring council, Lismore City Council.
The asphalt was initially laid in October 2013 by Lismore-based business Clark Asphalt in order to refurbish a main street in Casino. The resurfacing project had been undertaken by Richmond Valley on behalf of NSW Roads and Maritime Services (RMS).
However, last month, Richmond Valley announced the contractor would be returning to Casino to reverse and replace its earlier work.
“The asphalt is being replaced due to the discovery of inconsistencies in its quality, which could result in that section of road not reaching its design life,” a council media statement explained. “The remedial work … will involve removing and replacing about 1300 tonnes of asphalt to ensure the road’s long-term integrity.”
The second round of roadworks began on 13 January and was completed on 22 January. It was reported that the additional resurfacing cost Lismore City Council about $300,000.
Late notice on sub-par asphalt
According to The Northern Star, the asphalt had failed the standards set by RMS but Lismore had only discovered that some of the batches had been sub-par halfway through the resurfacing project.
“The lead up to it [the project] didn’t show any significant issues,” Lismore commercial services manager Phil Klepzig told the regional newspaper. “There was a whole range of tests done on it [the asphalt]; some were compliant and others were not. By the time we had enough results to say we might have a problem here … it was that close to the end of the job we may as well have finished it."
A Lismore City Council spokesperson told Quarry that several issues had occurred at once, but that the defective product had largely been due to the age of the asphalt plant located at the quarry site, which had caused some issues in the mixing stage. It was believed that a lack of air in the mix had led bitumen to rise to the surface of the roads under the weight of regular traffic.
Addressing the issue
Klepzig assured The Northern Star that the council had taken the necessary steps to ensure its quarry did not produce poor quality asphalt again, such as “ramping up” its laboratory testing regimes.
“We've spent a lot of time and effort on our quality assurance procedures; we’re now fully compliant under the relevant ISO,” he said. “We supplied a product, it didn’t quite meet the customer’s expectation, and so we replaced it. We took the view that we may as well go back and take the pain and fix it up now, and have a good product that’s going to last 10 or 15 years.”
Michael Caltabiano, CEO of the Australian Asphalt Pavement Association, told Quarry that neither Lismore City Council nor Clark Asphalt were members of the association, which enforces a code of practice for the production and laying of asphalt.
Caltabiano suggested the problem might not have occurred if the council had taken advantage of the extensive training available within the asphalt industry, or of the knowledge amongst its network of member companies which he claimed would have had the skills and ability to deliver the RMS’ requirements.
“The production and placement of asphalt is an engineered process that requires tight process control, compliant material selection and excellent plant control before the product reaches site,” Caltabiano said.
“Once on site, the correct handling, placement and compaction will deliver a quality project that will serve the community well. Smooth, safe and well maintained roads are essential for our community to prosper and are a significant investment in delivering this prosperity.”