Plastic wastes to the construction industry: An effective solution to prevent pollution

Concrete is a building material consisting of a hard, chemically inert particulate element called aggregate (usually sand and gravel), bound with cement and water in the construction industry.

Concrete has been essential to the Earth’s colonization. The Romans and Egyptians built their empires on it, and when its solid formula was lost, humanity had to invent it all over again in the 14th century (John Brownlee, 2016).

The annual production of concrete is about 500 million tons in the United States today is equivalent to about two tons per capita of its population. According to The Portland Cement Association (PCA), global concrete production is over 3.8 billion cubic meters or around 1.5 tons per capita.

According to Chatham House  (CH), the world currently produces 4.4 billion tons of concrete per year, but this figure expects to nearly double by 2050 as poorer countries rapidly urbanize (Jonathan Hilburg,2019).

As the market for concrete rises, the demand for the required concrete ingredients will also be higher, and more raw materials such as cement, fine aggregates and coarse aggregates will have to extract from the environment. Such volumes necessitate an enormous amount of natural resources.

It estimates that the production of one ton of Portland cement causes one ton of CO₂ emission into the atmosphere. CO₂ is a greenhouse gas that contributes to global warming, and the cement industry alone produces about 7% of it (C Meyer, 2004). According to statistics, dredging and aggregate mining in the benthic zone (seabed) harms species such as fish, dolphins, crustaceans, and crocodiles, as well as habitats and ecosystems.

Due to the depletion of natural resources and their impact on the environment, and several efforts have been made to incorporate byproducts and wastes from various industries into concrete as alternatives reducing the dependency on mining aggregates as virgin materials used generally in concrete for construction.

Every year, huge amounts of waste are producing, and the amount is increasing year after year.  Furthermore, the process of disposing of this trash through traditional ways has had detrimental consequences for the world ecology and economy.

Scientists and specialists have pushed to consider more effective remedies because of this. If waste products cannot eliminate in the first place, efforts should direct toward developing new markets for these products.

The current trend in concrete engineering is shifting towards sustainability, as natural materials for the production of concrete are becoming scarce, and the use of these materials is harmful to the environment.

Therefore, the sustainability of concrete production by using recycled waste materials to replace conventional materials in concrete is becoming increasingly important.

Several studies have been conducted to recycle wastes originating from various sources, including construction and demolition wastes and wastes from various industries, including steel, agriculture, glass, and rubber.

Since these wastes are abundant in certain nations, concrete manufacturing can reuse them on a large scale. The use of waste materials in concrete could help alleviate the excessive consumption of conventional materials while reducing the waste production.

Plastic is one of the solid wastes generated on a large scale and poses a serious threat to the sustainability of our planet. Plastic waste is increasingly accumulating in landfills and dumpsites and poses a threat to the environment.

An enormous amount of solid waste is produced every year, while only a small portion is recycled and landfilled, and much of the waste. Such as plastic wastes, are depositing directly or indirectly in the marine environment.

It estimates that about 380 million tons of plastic waste are generated per year (Hannah Ritchie & Max Roser, 2018). Due to its wide range of applications, such as automotive, industrial, packaging, and healthcare, large amounts of plastic waste are generating worldwide.

In 2019, global plastic production amounted to 368 million metric tons. The impact of COVID -19 on the industry is expecting to reduce production by about 0.3 percent in 2020 (Ian Tiseo, 2021).

Furthermore, these wastes have ended up in water bodies due to the high cost and energy associated with landfilling. Additionally, plastic’s limited biodegradability greatly reduces its recyclability and disposal in the environment.

Plastic waste has become a major environmental problem of modern civilization. Since plastic is making of various harmful compounds, it pollutes the earth, air, and water. As plastic is a non-biodegradable material, dumping it in landfills would preserve the toxic material indefinitely.

Plastics are hazardous in many ways. They have the potential to block a city’s sewer system. Clogged drains provide excellent breeding grounds for disease-carrying mosquitoes and waterborne diseases and cause flooding.

When plastic waste is mixing with soil, it can reduce the infiltration rate of rainwater and affect soil fertility. Plastic waste dumped into rivers, streams, and oceans pollutes the water and kills marine life. Plastic waste can consume by aquatic animals and cause health problems.

 Plastic particles and plastic molecules have been discovered in the stomachs and muscles of some aquatic animals. The ” Great Pacific garbage patch,” made up mostly of plastic debris, accounts for 90 percent of all trash floating in the oceans. According to the United Nations Environment Programme , there are 46,000 particles of floating plastic in every square mile of water.

Our ocean now contains 5.25 trillion macro and micro pieces of plastic, with 46,000 pieces per square mile weighing up to 269,000 tons. Each year, more than a million sea birds and 100,000 sea mammals die as a result of ingesting or becoming entangled in plastic debris (Dr. Nabajyoti Saikia and Jorge de Brito, 2012). Plastic waste appears to be posing an ever-increasing threat.

Many countries have banned or are in the process of banning the use of plastic bags. Plastic landfilling is also hazardous due to its slow decomposition rate and bulky nature. The waste mass may obstruct the flow of groundwater as well as root movement. Plastic garbage also contains a variety of harmful chemicals, including cadmium and lead, which can contaminate soil and water when mixed with rainwater.

In this situation, plastic recycling is a viable solution. Though plastic produces in the consistence of organic hydrocarbons, it has a high calorific value that can utilize in incineration or other high-temperature processes.

However, burning plastics releases many harmful chemicals into the air, including dangerous dioxins. After processing, it can use plastic waste to create new plastic-based products. However, the technique is not cost-effective because recycled plastic declines in quality, necessitating new plastic to create the original product.

 Even though all of these options are viable, recycling plastic trash to create new materials, such as cement composites, looks to be one of the greatest options for disposing of plastic waste due to its economic and environmental benefits.

Nowadays, plastic waste, such as polyethylene terephthalate (PET) bottles, polyvinyl chloride (PVC) pipes, high-density polyethylene (HDPE), thermosetting plastics, shredded and recycled plastic waste, expanded polystyrene foam (EPS), glass-reinforced plastic (GRP), polycarbonate, polyurethane foam, polypropylene fiber, etc. are now available in our civilization. When these plastic wastes use as sand-substitution aggregates, coarse aggregates, road pavers, and concrete blocks, in that case, they are found the same durable and strongness after investigations, which are exceptionally economically viable, cost-effective, and environmentally friendly materials.

Reference:

1. BY JOHN BROWNLEE, “Why Martian Concrete Might Be The Best Building Material In The Solar,” 2016. https://www.fastcompany.com/3055172/why-martian-concrete-might-be the-best-building-material-in-the-solar-system (accessed Oct. 01, 2021).
2. Jonathan Hilburg, “Concrete production produces eight percent of the world’s carbon dioxide emissions,” 2019, 2019. https://www.archpaper.com/2019/01/concrete-production-eightpercent-co2-emissions/ (accessed Mar 25, 2021).
3. C Meyer, “Concrete materials and sustainable development in the USA,”2004.
   Hannah Ritchie and Max Roser, “Plastic Pollution – Our World in Data.
   https://ourworldindata.org/plastic-pollution#how-much-plastic-does-the-world-produce (accessed Oct. 04, 2021
4. Ian Tiseo, “Annual production of plastics worldwide from 1950 to 2020| Statista,” 2021.
   https://www.statista.com/statistics/282732/global-production-of-plastics-since-1950/(accessed Oct. 02, 2021).
5. Dr. Nabajyoti Saikia and Jorge de Brito, “Use of plastic waste as aggregate in cement mortar and concrete preparation: A review,” Constr. Build. Mater. vol. 34, pp. 385–401, Sep. 2012, doi: 10.1016/J.CONBUILDMAT.2012.02.066.