Concrete is a ubiquitous building material globally. Because of its strength, durability, low cost, and applicability for different conditions, concrete is used to build houses, roads and bridges. However, concrete production is one of the main sources of carbon dioxide emissions in the world. Recently, Washington State University research team has created an eco-friendly and sustainable concrete using coal fly ash, which helps reducing greenhouse gas emissions generated during concrete production.
The ingredients of traditional concrete include cement, sand and etc. The production of traditional concrete contributes five to eight percent of greenhouse gas emissions worldwide. Because the production of cement, the main material in concrete, requires high temperatures and tremendous amount of energy, it has become the third-largest source of anthropogenic emissions of carbon dioxide, after fossil fuels combustion and deforestation. According to statistics, 0.82 tonnes of carbon dioxide was released from production of one tonne of cement in Australia.
Washington State University researchers used graphene oxide, a nanomaterial, to control the reaction of coal fly ash and water, and change the molecular structure in coal fly ash and transform into a binder like cement. No heating or usage of cement is required during the production process, it helps reduces greenhouse emissions. Furthermore, not only the coal fly ash concrete is stronger than traditional concrete in strength, but also it has pervious property.
Coal fly ash is a waste product of coal-based electricity generation, a tonne of this material is created every four tonnes of coal is burned. This material is sometimes recycled, but most of the times ended up at landfill, which is harmful to the surrounding environment. Utilizing coal fly ash as eco-friendly concrete could help reduce environmental impacts caused by coal-fired power generation and make our future more sustainable.
Sources:
https://news.wsu.edu/2018/07/12/coal-waste-makes-concrete/
https://newatlas.com/fly-ash-concrete-strong-green/55087/
https://www.chinadialogue.net/article/show/single/en/3836-The-ash-cloud-over-China