Combining cement with plastic may seem unconventional, but what is its intended purpose? The aim of using cement is to reduce plastic waste. Globally, plastic waste disposal has reached a critical point; cement could be a long-term solution to reduce environmental damage.
According to research by Plastic Oceans, a whopping 300 million tons of plastic is produced worldwide each year, with over eight million tons ending up in our oceans. Alarming predictions are that by 2025, there could be one ton of plastic for every three tonnes of fish, and by 2050, there could be more plastic than fish.
So why aren’t we recycling all that plastic? The fact that plastic comes in more than 50 varieties — some of which are commonly recycled, others not — makes it more difficult to sort and process than other materials.
But there is some good news on the horizon. According to several groundbreaking studies, combining non-recyclable plastic with cement to make sustainable concrete is one creative technique that helps reuse it.
Plastic is a sustainable aggregate for concrete. Experts say plastic can be a beneficial alternative to conventional aggregates, such as sand, which are mixed with cement to make lightweight and durable concrete.
This technique could be especially helpful in countries like India, which urgently needs a solution to its massive plastic waste and worsening sand shortage.
Cement mixed with plastic. Plastic resin pellets in hands
“We were approached by colleagues in India who wanted to solve two problems,” says Dr. John Orr, a sustainable construction specialist who was part of a 2014 research team that looked at these issues.
For the experiment, Dr. Orr and his colleagues collected a lot of plastic waste and shredded it into suitable sizes and shapes, then combined it with water and cement.
“First, there is a shortage of sand caused by dredging prevention, which has led to environmental problems; second, there is a significant amount of plastic waste because India recycles very little of it.”
The concrete industry is developing solutions, while other industries may be generating waste. Portland Cement Association
In addition to saving 820 million tons of sand per year, Dr. Orr states that “the environmental benefits of concrete mixed with plastic substitute are quite site-specific, but they provide one solution to plastic waste.”
They combine cement and plastic. Avoid Plastic Waste
When Henry Louis Miller, a student at Rensselaer Polytechnic Institute in New York, noticed that his area’s recycling program had been discontinued in favor of a cheaper disposal option, he was motivated to conduct similar research in 2009.
To create a more sustainable concrete product, Miller considered adding reclaimed soil from nearby brownfields along with ground-up plastic and cement.
His initial tests showed “strong and conventional concrete”, proving that plastics could be used without “negative effects”.
Plastic pellets
At the ALBA recycling centre in Berlin, Germany, bales of sorted rubbish are displayed in front of bins of pellets made from used plastics.
In a circular economy, cement
Additional research has been conducted around the world in recent years, underscoring the significant degree of innovation in the cement and concrete sectors.
With new regulations coming into force, such as the 2018 EU Plastics Strategy, which highlights the importance of moving towards a circular economy, such innovation could be crucial.
Through a series of waste treatment initiatives, the cement industry has been involved in the recycling of plastic for decades.
“Our industry has been delivering waste treatment solutions based on a circular economy approach for 40 years, thanks to co-processing technology,” says Thomas Guillot, Head of Geocycle Europe.
Plastic can be used efficiently to power the cement production process and in the cement mix itself. This ‘waste-to-energy’ co-processing reduces the amount of fossil fuel needed for cement production by burning non-recyclable plastic and adding kiln ash to the finished cement product. Furthermore, using plastic as an alternative fuel has no negative impact on emissions.
Moreover, using plastic as an alternative fuel has no negative impact on emissions.
Industry supports the idea of saving resources in Europe, which includes the creative reuse of plastic waste.
Currently, waste such as plastics and biomass provides about 43% of the thermal energy used to power clinker used in cement production in Europe. In the next five to ten years, this percentage could increase to 60% or even 80% with existing technologies.
“The cement industry is one of the most innovative and progressive industries and a rich source of potential solutions, not only for non-recyclable plastics but for literally thousands of other materials,” adds the Portland Cement Association in the US, emphasizing the long-standing importance of innovation in the success of the cement industry.
Combining cement with plastic. And can you dissolve cement mixed with plastic?
Yes, for now, the amount of plastic mixed with cement is not large enough to make it impossible for professional cement dissolving fluids such as BETOFF to cope. As mentioned above, the cement-plastic mixture contains approximately 10% plastic, which is not enough to prevent the BETOFF liquid from dissolving the cement. Of course, the BETOFF liquid does not dissolve plastic, and if there were more of it in the cement-plastic mixture, e.g. 50%, then the liquid could have a problem dissolving the cement.
