Fix Your Future: Climate Action SDG 13

Hello! WE ARE TEAM BOBA And today, we will be talking about how waste management will play a big role in making Auckland a circular economy. Our focus is the construction industry.

Let’s get back to basics. Why is the construction industry relevant to climate action? What can be improved? Let’s get back to basics.

Creation of Cement Cement is created from mixing superheated limestone and clay. To reach the heat of 700°C, combustion reactions created by fossil fuels are used. This creates a lot of CO2 emissions in itself. Additionally, the chemical reaction of the two materials fusing also produces CO2 as a byproduct. Anaerobic digestion (AD) of organic waste to create biogas which can be used to trigger the combustion reaction. Companies like Eco Stock & Scion have already invested in AD plants. Fossil fuels are still cheap compared to biogas. Therefore, in the future, Auckland Council may assist in making biogas a marketable commodity via subsidy.

Problem Number 2 with the Construction Industry RECYCLING CONCRETE Problem Number 2 with the Construction Industry

Construction and demolition waste also represents Auckland’s largest single waste stream, at around 40% of total weight going to landfill. - Auckland Council

Concrete is 100% recyclable. Structural integrity is tightly regulated and many private building projects that use recycled concrete requires consent. There is also low market demand for recycled concrete due to the availability of virgin concrete. You can grind demolished concrete into aggregates and add it as an ingredient to “virgin concrete”. This will affect the quality and strength of concrete but not unreasonably.

ANOTHER CHALLENGE: Transportation Concrete recycling is done by sorting out uncontaminated rubble by size. This is difficult to do on-site where most recycling is done. Therefore, off-site concrete recycling sector in coordination with on-site recycling must grow.

How do we inspire the use of recycled concrete? Non-load bearing purposes RECREATIONAL With urban development comes residents wanting recreational benefits. E.g. Ruakura Inland Port. We can introduce Skate Parks, Basketball & Tennis Courts. PRIVATE Many New Zealanders live on farms or own baches. To get better access to these areas, they can use recycled concrete in replacement of gravel. Carports, driveways, pathways.

Becoming circular with Crushed Glass A study done by the Ellen MacArthur foundation observed that glass is a superior aggregate ingredient in concrete compared to other recycled materials. The major expense of recycling glass is the sorting of it.

To summarise: Fossil Fuel Reduction On-site and off- site recycling Biogas use will lead cement creation to becoming a carbon neutral process. On-site and off- site recycling Will reduce cost of recycling and economic feasibility of marketing recycling concrete. Recycled Glass Additive Will introduce more uses for recycled glass. Non-load bearing usages Will inspire the usage of recycled concrete to the public. Circular economy Recycled concrete will attract jobs and economic growth in this sector, also drastically reducing concrete waste.

Thanks for listening!