As the world at large continues its search for more sustainable materials and methods, with a lower impact on the environment, that will still allow us to continue with our daily lives, researchers from the Civil Engineering Department of Universiti Teknologi MARA in Shah Alam, Malaysia, have come up with a new environmentally friendly version of building concrete. They’ve called it green-mix.
The Government of Malaysia has been encouraging construction firms building in its country to consider more than simply price and performance when selecting their designs and materials for some time. In 2009, the Green Building Index, or GBI, was introduced to motivate the construction of new buildings using greener technology and incentives are still offered to owners of older buildings to try and meet GBI standards.
And when considering air pollution, a large proportion of the world’s carbon emissions come from cement and concrete production. It’s with all these factors in mind that researchers set about developing a new and innovative green building material.
Countries around the world, including Malaysia have been using ‘green’ concrete for a few years now. To qualify as a green concrete, the material needs to be at least partially made up from sustainable materials or recycled waste product so it can reduce the amount of raw materials needed in production, or reduce landfills.
For this particular ‘green-mix’ concrete, the UiTM researchers used a mix of recycled concrete aggregates, aluminium can fibres and fly ash, a waste product from coal-powered electricity plants that’s normally buried in landfill sites or dumped in ponds. The researchers found that the ash performs well as a replacement for cement, thus reducing air pollution caused by cement production. Re-using crushed concrete as aggregates lessen the consumption of raw materials and recycles the waste produced when old buildings are demolished, while aluminium cans are easy to turn into fibres for use as reinforcement.
Although green-mix concrete production does need a new understanding of the concrete mix design, the raw materials and a new knowledge of green concrete properties, tests have shown that it’s up to 30% stronger than regular concrete, in addition to being far less environmentally damaging. Thanks to optimised material proportions from the new mix design, green-mix concrete is also cost effective.
So, in the end, green-mix is claiming to be the answer to both developers and contractors need for a green concrete alternative that allows them to meet various nations’ environmental technology policies; have a lower carbon footprint per unit produced than regular concrete, due to the use of far less cement; provide an alternative and productive means for the disposal of coal plant and demolition site waste; and is still able to provide the required strength and performance needed during the service life of a building.
Seems like it does it all.