An initiative incorporating recycled crushed glass (RCG) in concrete used on the Pacific Highway in northern NSW is in the running for a national construction award.
About 1500 tonnes of crushed glass sourced from the Lismore City Council (LCC) was substituted for sand in a batch of lean mix concrete totalling about 12,800 cubic metres. This was laid over 8km of the Pacific Highway from Wells Crossing to Glenugie.
The project is a first for main line pavement on Pacific Highway projects, and last month it was nominated as a finalist for the 2021 Australian Construction Achievement Award.
The Wells Crossing-Glenugie project followed an earlier trial also using LCC-sourced crushed glass as a substitute for coarse sand incorporated into concrete for highway construction.
Lismore Council recovers and separates waste glass locally through its collection processes and the NSW government’s “Return & Earn” initiative.
The waste glass is stockpiled and then crushed to produce RCG suitable for a range of construction uses such as an alternative to bedding sand and coarse sand substitution within concrete.
The Lismore City Council, Transport for NSW, Pacific Complete, and engineers Acciona were principal partners in the Wells Crossing-Glenugie pavement project.
While RCG’s use as bedding sand is now relatively accepted within industry, its application within concrete is less common, despite allowances within client specifications.
According to the Infrastructure Sustainability Council of Australia, the lessons learned from the Pacific Highway project will help assess the viability of RCG for future applications.
“With further application of this initiative, we believe the demand and efficiency of scale will further drive the cost per tonne down and compete with conventionally sourced materials.
“We are hopeful this will start to develop a viable business case for the use of RCG in concrete which could be adopted by clients and contractors more broadly and strengthen the drive towards a circular economy.”