The Construction Industry Rises to the Plastics Challenge

As the world wakes up to the environmental challenges posed by massive plastic consumption, the construction industry is reducing its reliance on single-use plastics and increasing use of recycled plastics. In the seventh edition of our construction magazine Building Sight, we look at how the construction industry is tackling environmental issues and aiding countries to reduce emissions and meet ambitious targets.

Plastic items can take up to 1,000 years to degrade in landfill, but the material’s reputation has disintegrated a lot faster. Heightened awareness of its effects on the environment has prompted businesses and individuals to reassess their relationship with plastic.

As a major consumer of single-use plastic, the construction industry could help to drastically reduce waste by using less and reusing more in the form of recycled materials.

The most common plastics used in construction are polyvinyl chloride (PVC), high density polyethylene (HDPE), and expanded polystyrene (EPS). Plastic is used for various applications such as seals, windows and doors, pipes, cables, floor coverings, and insulation.

The industry also traditionally uses plastic films for packaging. Where facilities exist and the systems to manage recycling are in place, packaging can be bundled up and incinerated in energy-from-waste plants.

Not all plastics are bad, and consumption within the industry looks set to increase, with plastic pipes, for example, already accounting for most new pipe installations.

“Contrary to popular belief, it’s important to acknowledge that plastics in construction are often a positive thing,” says Allan Sandilands, principal consultant at the sustainability consultancy Resource Futures. “Many are highly durable, long lasting, and permanently installed, so they’re unlikely to become marine litter,” he says.

Additionally, plastics are cost-effective, strong yet light, easily formable, and easy to maintain.

“The main challenge in construction is around efforts to segregate, reuse, and recycle plastic waste at the end of its life,” says Sandilands. “The benefit isn’t always financially significant — it’s more in terms of corporate social responsibility and commitment to best sustainable practice — so it can be a difficult sell.”

“From our experience there has not been a huge drive to tackle single-use plastics in the construction industry in the same way that we’re seeing elsewhere, because it’s insignificant in terms of tonnage compared with other waste streams and doesn’t greatly affect contractors’ bottom lines.”

The need to protect the corporate environmental reputation is moving up the risk agenda within the construction industry, believes Robinson Zhang, acting infrastructure and mining leader for Marsh in China. “There have been high-profile cases where construction projects have caused damage to the environment, and we know these negatively affect the reputation of companies involved.”

Action Plans

Some companies are trying to make a difference, recognizing the reputational benefit of doing so.

In 2019, German developer and builder Diringer & Scheidel Group used recycled plastic in the construction of a 13-storey residential tower to save 1,613 tons of concrete and 136 tons in CO2 emissions. The build used a patented void-former system made from recycled plastic from Heinze Cobiax Deutschland.

Essentially, steel-reinforced air bubbles were used to replace up to 35% of reinforced concrete normally required in slabs.

In the UK, Mace is one of several firms to set itself targets for reducing plastics, through its “Time to Act” campaign.

In conjunction with clients and the company’s supply chain, Mace has measures on its sites to reduce single-use plastics, including using reusable shoe covers, a closed-loop system for protective plastic sheeting, and a trial of reusable skip liners for concrete washouts.

Mace has also worked with its mechanical and electrical supply chain to change how it uses plastic — with one supplier of MEP modules and cables reducing single-use plastics in its products — as well as plastics in its packaging, to save the equivalent of 40 tons of plastic waste a year.

Mace has also instituted a program of beach and river cleanups everywhere from North America, the UK and Ireland, to Dubai and Vietnam, and has collected an estimated two tons in plastic waste. It is now looking at how to increase its use of recycled materials.

Contractor Multiplex launched a plan in July 2019 with two key focus areas: Eliminating single-use plastics, and promoting circularity of existing plastic items.

Called “7:5:3,” the plan tackles 15 plastic categories by either banning single-use-plastic avoidable items, replacing plastic with alternatives, or finding a new use for the end of their life.

For example, Multiplex’s site canteens no longer sell single-use plastic bottles, while at its £200 million Principal Tower project in London it switched from plastic mastic tubes to foil mastic tubes, saving over 9,290 tubes of single-use plastic tubes and reducing the volume of packaging waste produced by 96%.

While the international construction sector has a long way to go, firms could be driven to take more care over plastic waste and materials generally as nations outline plans to target zero-carbon emissions by 2050 under the 2015 Paris Agreement.

Construction firms can examine carbon material databases such as the Inventory of Carbon Emissions, or Trafikverket’s Klimatkalkyl , to gauge levels of embodied carbon in different forms of plastic as a starting point for determining how to reduce consumption in the most environmentally friendly manner.

The first step for any contractor committed to reducing plastic consumption is to create an action plan, advises Isabel McAllister, Mace’s director for responsible business.

“It’s a long road, but the first step, is to review key packages to see which will result in the most reduction, and focus on those. “Go after the ‘easy wins’ first,” adds McAllister.

“Switching from plastic catering products and packaging, using reusable cups and glasses, buying products in bulk for cleaning, and generally reviewing office deliveries and how items are packaged are all easy wins.

“On site, the solutions may be more niche, but we have created a resource of the options we have trialed, which is available to our sites to work with contractors to see which items are feasible for them.

Consumer Waste, Construction Resource

Waste plastic from consumers has the potential to become an important resource for construction. Some building products — such as pipes and UPVC doors and windows — already include a proportion of recycled material, but new applications in construction are emerging fast.

From an embodied carbon perspective, plastic is far less energy intensive to produce than traditional materials such as concrete and steel, especially when recycled. It also has engineering benefits such as its high strength-to-weight ratio, durability, and resistance to corrosion. Combine all those characteristics, and you have an environmentally attractive proposition. 

Dutch firm KWS, part of the VolkerWessels group, had this in mind when it created PlasticRoad, a prefabricated road system made from 100% recycled plastic. It comes in hollow modules that are fitted together. Utilities run through the hollow section, with easy access for installation and repair.

KWS, working in partnership with oil firm Total and drainage product manufacturer Wavin, constructed a city

bicycle lane in 2018 as a trial project According to KWS, PlasticRoad will last three times as long as an asphalt road surface and require less maintenance.

Recycled waste plastic is also being used to reinforce asphalt in road surfaces. UK company MacRebur, for instance, makes pellets from plastic waste that melt into the asphalt mix to create a stronger more crackresistant road surface.

Bridges are another contender for recycled plastics.

The world’s longest span recycled plastic bridge, at 30 meters, was installed across the River Tweed in Peeblesshire in Scotland, in 2011. There are several in the US too, where the system was pioneered.

The challenge in creating any product from recycled materials is ensuring the quality of the feedstock. That requires changes in technology and changes in attitude — to consider used plastic as a resource rather than waste.

As economies around the world grapple with how to move to a new circular plastics economy, construction is well placed to become an important part of the circle.