Concrete has been a material that’s been used for centuries as the foundation for just about everything from roads, bridges, buildings, irrigation ditches, seawalls and more. But, with the COVID-1 pandemic (and climate change) making things worse not just for the construction industry, but for everyone else, concrete suppliers had to deal not just with supply chain hitches but also labor shortages, and protests from environment groups as well as government regulators. Read on to learn how concrete has undergone a major facelift (literally) and has gotten a new, greener or more sustainable recipe or mixture.
Global Cement Production Accounts for 8% of Carbon Emissions
If you think that your local concrete suppliers are worried only about supply chain disruptions and labor shortages during these complex and challenging times, think again. In fact, they’re also worried about climate change and rising levels of greenhouse gases!
According to a study that was published in 2019 by the National Academy of Sciences, it was estimated that cement production worldwide has accounted for 8% of global carbon emissions, which makes it the largest single industrial emitter of carbon dioxide!
While concrete has given us amazingly sculptured buildings and other structures, it sadly is responsible for making hurricanes and tornadoes stronger and more terrifying. If concrete were a country, it would actually rank 3rd in emissions behind China and the US!
Well, in the US alone, an estimated 370 million cubic yards of concrete were manufactured last year, with around 40% of it going into the commercial real estate market.
However, in recent decades, architects, engineers, real estate developers, as well as concrete suppliers, have sough to lower the carbon footprint of buildings and other structures, and have also focused on reducing energy use by improving the efficiency of heating, lighting and other systems related to producing and utilizing concrete.
And, to lower carbon emissions even further, these industry groups and stakeholders are looking beyond such operation matters to the carbon that’s emitted in the production and transportation of concrete and other construction materials.
However, even before climate change and greenhouse gases even became pressing and more popular global issues, concrete producers and suppliers have already sought to reduce the amount of cement in their mixes, for the simple reason that they wanted to cut costs, in part because of the energy-intensive heating in producing cement.
New & Greener Mixes for Concrete
With more and more people getting worried about the phenomena of global warming, various industries across the planet have felt the pressing clamor to go through a green revolution. In other words, this means that all industries need to adopt, introduce as well as embrace environment-friendly materials.
With this understanding, the concrete industry as a whole has surprisingly found a couple of sustainable and environment-friendly alternatives to concrete, of which they aptly refer to it as Green Concrete.
Let’s look at one eco-friendly alternative that many concrete suppliers are enthusiastically promoting, and it’s called “Ashcrete”. Ashcrete is actually fly ash, which is a by-product of combustion of coal, which was previously discarded or thrown away in landfills. However, today, i’s now be utilized for manufacturing green concrete.
This type is fast becoming an alternative substitute for traditional concrete, and it’s mixed with lime and water to make it strong and durable, and quite similar to conventional concrete. The good thing with ashcrete is that it can replace conventional cement, but emits way less carbon dioxide.
The other advantages of ashcrete include the increased strength of concrete, reduced bleeding, and reduced shrinkage. Fly ash also makes concrete more resistant to alkali-silica reactivity.
Another type of green concrete is blast furnace slag. Just like fly ash, blast furnace slag is a by-product which can easily be recycled and utilized as an eco-friendly alternative to concrete. This glassy, granular material is made by quenching molten iron slag from the blast furnace into water or steam.
Micro Silica, or “silica fumes” is an ultra-fine powder that’s a by-product of ferrosilicon alloy and silicon production. This can displace around 7% to 12% of the cement in concrete, and is known for its ability to improve the durability of concrete by making it less permeable, and enhancing its compressive strength.
Aggregate replacement is another green alternative to traditional concrete. Instead of finding substitutes for cement, replacing aggregate materials with reusable and recyclable resources is deemed a more effective way to reduce greenhouse emissions that are brought about by traditional concrete.
Among the examples of aggregate alternatives include waste plastic, paper/fiber, post-consumer glass and concrete debris.
Paper-crete or fibrous concrete is also fast becoming a green alternative to traditional concrete. This is made using waste paper, which is reused and recycled as an aggregate material for making concrete.
While fibrous concrete does not entirely replace cement in the mix, even small quantities of paper-crete is enough to reduce, or even ward off, the negative effects of concrete production and use.
The use of concrete debris is also an amazing, and eco-friendly way of utilizing waste concrete material, and for cutting down the consumption of natural resources from the concrete production process.
This process also saves (as well as reduces) landfill space, and the reuse of debris also cuts down on the utilization of virgin raw materials.
Post-consumer glass and plastic waste have also become cost-efficient and eco-friendly alternatives to producing concrete, and these have also made concrete suppliers grin with delight because it also makes them major contributors in making the planet a healthier place to live in.
Being a versatile inert material, glass is suitable for aggregate replacement in concrete, because it can be recycled and reused a lot of times without making any changes in the chemical properties and durability of concrete.
The use of plastic waste as an aggregate for making concrete is also hailed as one very smart move, because plastic waste is a non-biodegradable material. However, it is easily recyclable, and it can easily replace up to 20% of traditional aggregate material.