Auckland's Climate Action Plan


Concrete & cement is the cornerstone material for the construction industry; unfortunately it is a large contributor to CO2 emissions.

This is due to the creation of cement, which requires the heating of limestone and clay to extremely high temperatures before they can mix. In order to reach the desired heat, a lot of fossil fuels are combusted, releasing CO2. Also, when limestone is heated it produces additional CO2 in the chemical reaction that takes place.

We can reduce these emissions by reducing the amount of cement we create. This is possible by recycling the already existing concrete from demolitions. Unfortunately, 40% of concrete is thrown into landfill and it accounts for NZ's largest stream of waste. This is even more frustrating to realise when you know that concrete is 100% recyclable. It can be crushed up and added as an aggregate ingredient to virgin concrete.

The reason why this hasn't yet taken place is because of regulation around the structural integrity of usage of recycled concrete and also low market demand in the construction industry. I believe both of these issues can be remedied if Auckland Council sets this issue as one of its priorities.

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edited on 14th August 2018, 20:08 by Brian Kasmara

Richard Neate 7 months ago

You can use crushed concrete as aggregate which would reduce the amount of rock quarried but you would still need to add the same amount of cement. I can't see how this would reduce cement manufacture at all?

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