Polystyrene waffle pods have been used in the residential building sector for several years with project stakeholders achieving significant cost savings in construction. Taking inspiration from this, MidCoast Council in NSW used these waffle pods to address cost challenges during the construction of a culvert.
The job of maintaining and upgrading local roads, bridges and waterways is a constant challenge for local Councils, necessitating a balance between delivering quality services for their community while working within budgets and timeframes.
In a world’s first culvert construction method, MidCoast Council used polystyrene waffle pods in the tunnel that carries the stream underneath the Belbora Creek Road, north off The Bucketts Way between Taree and Gloucester, helping them achieve dramatic cost savings that cut the $400,000 budgeted cost of the works to $186,000.
Grant Calvin, a senior survey designer with MidCoast Council was awarded the Keith Haddon Award for his paper on this project, Building a Bridge with a House Slab. He wants other councils to know about the innovation.
“We’ve improved the level of service, done it in a sustainable way, it’s cost effective. Those are the catch phrases that are thrown around local government and we ticked them off,” Calvin said.
“The waffle pod system provided a quick, cost-effective method to install a low-level bridge, or culvert over the existing concrete causeway. This method maintained and built upon the existing infrastructure, provided a higher level of service to the road and in this instance preserved significant aquatic habitat and irrigation access upstream of the structure,” his paper concluded.
Carey Molloy from Matrix Thornton Consulting Engineers was part of the team challenged to come up with a solution for the culvert that could deliver significant improvements for the waterways and the budget. After considering 20 different options, the team found that waffle pod technology developed for residential concrete house slabs ticked all the right boxes.
“It was bloody obvious really,” Molloy said. “Waffle pods came out on top in the cost-benefit analysis and we reuse them after you dig them out.”
The use of waffle pods in the design not only enables rapid low cost construction and meets rigorous local government structural requirements, but also allows for the existing causeway to remain in place, reusing the existing infrastructure and minimising creek bed disturbance.
Foamex StyroPod is a strong yet lightweight polystyrene waffle pod void former system for concrete slabs. Foamex StyroPod provides under slab insulation and support, while reducing the effects of soil movement, and lowering the amount of concrete required for a build.
