The contribution of concrete, and particularly cement, production to global carbon dioxide emissions is well established (roughly 8% of total). In the last ten years there has been a concerted effort to find practical pathways to reduce the carbon footprint of concrete infrastructure but this has led to plethora of options and directions in the quest for a ‘low carbon concrete’. Through the National Asset Centre for Excellence (NACoE) programme, TMR Structures has run two projects to distil down what ‘low carbon concrete’ really means and what options the department should be concentrating its efforts on.
This presentation will describe the possible solutions for reducing the environmental impact of concrete infrastructure, how they relate to TMR’s sphere of influence and then hone in on what can be done now and into the future.
The most straightforward response is to increase the use of supplementary cementitious materials (SCM) in cement blends. Australian Standards are in place, the advantages for concrete durability are known, and supply chains are relatively well established. However, there is a concern that the availability of these materials, particularly fly ash will drop once coal power stations are shut down.
Part of this research therefore looks at the feasibility of harvesting the fields of ash deposited as waste at power stations as a future source of SCMs by testing samples against the requirements of AS 3582.1. Early results are promising, that with some processing the material is sufficient for the departments needs in the medium-term.
