Recycled Plastic and Gamma Rays Increase Concrete Performance

There are several applications of recycled plastic, or non-recyclable plastic waste, which have been tested in the construction sector, with the aim of helping the system to dispose of the waste that we produce and, at the same time, improve the circularity of a sector that needs to integrate into the great common goal of producing and consuming the least amount of natural resources and having as little impact on the environment as possible.

The use of recycled plastic is already present in many commonly used products in construction, as we will see later, but fewer successful projects have been in the use of non-recyclable plastics, such as for example polylaminates or waste from washing plants, a mix of heterogeneous plastics that cannot be separated mechanically.

In the road asphalt sector, mixtures of bitumen and non-recyclable ground plastic have been successfully used as described in the article that you can read below.

An interesting project concerns the use of ground plastic in cement mixtures, the result of various attempts, some unsuccessful, which allowed to find the key to having a cement mixture with improved performance compared to the traditional one, as Luisa Dalaro tells us.

In fact, we don't want to talk about the concrete we all know, but about a particular concrete, “plastic concrete”.

One might think of a cement with lower performance, poor quality at first glance, but instead it can be a valid alternative to the classic concrete, in a context of growing interest in the recycling of materials deriving from urban and industrial solid waste.

This modus operandi represents an efficient solution to the depletion of natural resources and, at the same time, an effective method of waste disposal.

Recycled materials are a valid alternative to typical building materials, as long as the transformation process requires a lower consumption of energy and raw materials than the production from scratch . Much of the waste is plastic, so plastic is a material that must be recycled or reused as much as possible.

In construction, recycled plastic is widely used for the construction of floors, insulating panels, pipes, crawl spaces and window frames. More extreme experiments involve the use of plastic bottles in the concrete casting.

In particular, the recycled plastic of used bottles could lead to the production of a more resistant and ecological concrete.

More resistant eco concrete: experimentation

And here is the result of a research by some scholars of the MIT (Massachusetts Institute of Technology), whose proposal could be the solution capable of reducing the environmental impact of concrete production and find large-scale use of recycled plastic.

MIT scholars had hypothesized that by mixing flakes of recycled plastic into the cement mixture, the physical properties of the latter could have been improved, but unfortunately the result it was disappointing.

The scientists continuing their research on this path, found that by subjecting the plastic to gamma rays, using a cobalt-60 irradiator that emits gamma rays (usually used for decontaminate food), the recycled and then pulverized plastic flakes crystallized, becoming perfectly assimilable and “incorporated in a uniform manner” by the concrete.

The powder thus obtained was combined with various cementitious compounds, which were then poured into cylindrical molds, and then subjected, once solidified, to tests of compression. Test results confirmed that plastic cement is about 15% stronger than traditional concrete.

The new concrete mix has shown incredible properties: such as increased strength and flexibility. "We observed that within the parameters of our test program, the higher the irradiated dose, the higher the strength of the concrete, so more research is needed to customize the mix and optimize the process with irradiation to get even more results. best.

The process we have developed has enormous potential both in terms of sustainability and resistance. " - Kupwade-Patil, MIT researcher.

Related articles:

Glass and Non-Recyclable Plastic: is there an Alternative to Landfill?

Automatic translation. We apologize for any inaccuracies. Original article in Italian.