The production of cement used in concrete is thought to be responsible for 5-8% of global carbon dioxide emissions, but a new approach to making cement has the potential to reduce both greenhouse gas emissions and water consumption. In its raw state, concrete dust is environmentally friendly, as it is a natural component. However, it is in the industrial extraction of the materials, the mixing and application of the concrete that it is no longer environmentally friendly. Today, concrete is the most consumed man-made material in the world and the second most consumed material on the planet after water.
It is durable and reliable, affordable and adaptable to many designs. In addition, concrete's thermal stability allows for more energy-efficient buildings. Unfortunately, only coal, oil and gas are major sources of greenhouse gases when it comes to materials. One of the main components of concrete is cement, which has its own environmental and social impacts and contributes greatly to those of concrete.
This value is based on mix proportions for concrete that do not exceed 20% ash. In the time it takes you to read this sentence, the global construction industry will have poured more than 19,000 tubs of concrete. This is mainly because the materials used in concrete construction, such as aggregates, pozzolans and water, are relatively abundant and can often be obtained from local sources. Hoffmann Green Cement Technologies (HGCT) is a pioneer in its field, as it is the first in the world to offer carbon-free concrete.
By combining green concrete with non-toxic sealers and dyes, you can have a beautiful concrete floor that is also environmentally friendly. Fly ash and other green concrete products are already available on the market in many countries, including Australia. In addition, concrete production requires large amounts of water, and overall production accounts for almost one tenth of the world's industrial water use. Of course, it is much easier to mobilise a nation to do something that improves people's lives, but either way concrete is likely to be part of the deal.
In France, the team at the design office Elioth, a subsidiary of the Egis group, intrigued by manufacturers' promises to reduce CO2 emissions, undertook life cycle analysis calculations for new generation concrete. One aspect of the life cycle of concrete that is worth highlighting is its very low embodied energy per unit mass. Specialists set out to develop an environmentally friendly solution to drastically reduce the carbon footprint of concrete manufacturing. Sacramento's Cool Communities programme was involved in the project which used permeable concrete for stormwater management and to reduce the urban heat island effect.
This was achieved by directly injecting recycled liquid carbon dioxide from third-party industrial emitters into the wet mix phase of the concrete during manufacturing process. Combined, cement and the concrete made from it are an environmental disaster.
