Making Cleaner Concrete

Concrete has been around for centuries and has proved so successful that around 4.1 billion tonnes of cement were produced worldwide in 2019, making it the most widely used substance on the planet after water. 

Unsurprisingly, there is a price to pay for this level of production. The manufacturing of concrete’s key ingredient, cement, is responsible for around eight percent of global carbon emissions, and The Global Commission on the Economy and Climate predicts that the construction sector will emit 470 gigatonnes of CO2 by 2050 if developing countries increase their infrastructure to average global levels. 

A rise of this nature would far exceed the 2015 Paris Agreement on climate change, which aims to reduce annual carbon emissions from the cement industry by at least 16 percent by 2030 to help the world target of stay within a 1.5C to 2C rise in global warming.

Unfortunately, concrete has several other harmful effects. It accounts for almost a tenth of the world’s industrial water use, while quarries and cement factories are often air pollution sources. Finally, concrete production requires 50 billion tonnes of sand and gravel every year, which is destroying many of the world’s beaches and riverbeds.

But with few alternatives to concrete that could be used on a mass scale, the industry is trying new methods to lessen the environmental impact of production. For example, recycled glass that can’t be reused by consumers is being crushed into a powder that can be used in the concrete mix. Several companies have experimented with liquid injections of CO2 into wet concrete, which forms a mineral, calcium carbonate, making the concrete stronger and trapping the greenhouse gas.

At Bee’ah’s new Headquarters, we have used glassfibre-reinforced concrete for our exterior panels. This material is greener compared to traditional concrete, due to the reduced CO2 emissions during the manufacturing process, its durability in extreme weather conditions, and the lightness of its material, which reduces transportation demands. 

Experimenting with the concrete recipe is not new: for several decades fly ash from coal-burning plants, and slag from the production of steel are used in the concrete mix to save on costs. This had the added benefit of diverting this waste from landfills, while improved recovery techniques in recent years have made the process more efficient and greener. Unfortunately, fly ash is not so readily available in such quantities as a growing number of countries move away from coal stations, while the decline of steel production in some nations has reduced the availability of slag. 

Thankfully, there are often new and unexpected solutions to environmental issues if we are resourceful. Bee’ah firmly believes in the many benefits of a circular economy, where materials are reused in multiple ways. For example, once we operate the UAE’s first waste-to-energy plant in Sharjah next year, we will process more than 300,000 tonnes of waste annually, generating around 30 megawatts of energy and displacing almost 450,000 tonnes of CO2 emissions yearly. The process also leaves behind residual ash, such as fly ash and bottom ash, which can be reused for other purposes – including as a bulk fill for products such as asphalt and cement.

Meanwhile, we are ensuring that construction waste, including concrete, are recycled for future use. Our Construction and Demolition Waste Recycling Facility is already one of the busiest of its kind in the world, processing 500,000 tons of waste annually that can then be reused productively. 

These are just two examples of ways we can offset the environmental impact of concrete production. If we continue to apply ingenuity and resourceful thinking, I am sure that many other solutions will be developed in the years to come.