Towards a sustainable asphalt and bitumen industry

The second SATBinderrr conference hosted by the Society for Asphalt Technology (SAT) in September 2022 was about sustainability, and for many practitioners a high point in a difficult year beset by bitumen shortages, a lack of infrastructure budget, and Eskom’s woes, among others.

SATBinderrr doubled in length to two days on 21 and 22 September this year, with a hybrid model that attracted 169 delegates at the physical conference at the CSIR International Convention Centre in Pretoria, together with another 111 online delegates.

The inaugural conference in 2021 attracted almost 250 online delegates and the large number of practitioners who returned in 2022 agreed that the content provided in the 31 presentations and two panel discussions took the coverage of what is important in the industry to new levels of excellence and innovation.

“I am extremely proud of what Krishna Naidoo, the incoming SAT president, and his team managed to put together at SATBinderrr 22,” said Herman Marais, outgoing president, SAT.

“The greatest achievement of this conference was the emergence of a new generation of road engineers and specialists with a passion for our industry. SAT Binderrr has now set the benchmark for conferences aimed at young and established professionals in the roads industry, which was evident in the average age of the delegates. The vibrant young leaders soaked up all the knowledge and information that was presented.”

One of the highlights was an informal ‘Get to Know Louw’ session in which Louw Kannemeyer shared his professional career journey from humble beginnings in a small farm school in the Free State to executive: Engineering Services at Sanral today. This personal insight was a great learning experience for many, driving home the importance of passion and commitment among young people to sustaining the industry at a high level of excellence.

USA sustainability initiatives

Audrey Copeland, president and CEO of the National Asphalt Pavement Association (NAPA) in the USA, added an international perspective to the strong sustainability theme that underscored the conference. A highly respected leader in the international asphalt sector, Copeland shared some insights into the size and scope of the industry in the USA and steps being taken to mitigate climate change.

NAPA represents asphalt producers and paving contractors, and has more than 1 100 members nationally. According to Copeland, the US has some 3 500 asphalt production sites. More than 94% of the 2.6 million miles (over 4 million km) of paved roads in the US are surfaced with asphalt, as are 85-90% of all runways at the nation’s 3 364 commercial airports.

In 2020, more than 400 million tonnes of asphalt mixture were produced in the US – a significant step down from the 500 million tonnes per year achieved in the early 2000s. The industry employs about 750 000 people directly and indirectly.

Copeland pointed out that total annual expenditure on asphalt pavement surfaces, mainly funded by government, is US$25 billion (R455 billion).

One of NAPA’s main drives is towards sustainability and resiliency, a focus that began 10 years ago and is driven by a dedicated director of sustainability. “This focus is integral to efficient operations and reducing costs, as well as benefitting the environment,” she said.

A NAPA initiative launched in January 2022, ‘The Road Forward: A Vision for Net Zero Carbon Emissions for the Asphalt Pavement Industry’, calls on the US asphalt community to advance technologies, products and processes to achieve net-zero carbon emissions by 2050. “This multiyear effort will engage, educate and empower the US asphalt community to produce and construct netzero carbon emission asphalt pavements.”

Sustainability practices typically result in cost savings, and efforts to lower carbon emissions provide significant grant opportunities from the US government. ‘Buy Clean’ legislation is also being passed in several states, while federal agencies are also adopting Buy Clean policies. Sustainability initiatives are increasingly impacting the value of US businesses, along with their ability to recruit and retain employees and attract investment.

The power of recycling

Copeland emphasised that the initiative is being driven by NAPA’s members with the focus on education, science and engineering rather than as a marketing exercise. She added that achieving net-zero production and construction will need buy-in from the entire US asphalt community – from producers to researchers to specifiers.

“The effort starts by focusing on the way we operate. In 2019, for example, the industry’s use of reclaimed asphalt pavement (RAP), and increased use of natural gas relative to the industrial sector as a whole, resulted in 2.9 million metric tonnes of avoided greenhouse gas (GHG) emissions, equivalent to the annual emissions of 630 000 passenger vehicles,” said Copeland.

“The progress in the use of warm-mix asphalt (WMA) technologies is another great example of the partnership between agency and industry.”

The impact of RAP utilisation has been significant in the USA. Estimates show that the use of RAP saved 24 million barrels of liquid asphalt binder, 82 million tonnes of aggregate, and $2.9 billion (R52.8 billion) in 2020 alone.

The same survey evaluated GHG emissions, finding that US RAP usage from 2009 to 2020 saved 23.5 million metric tonnes of carbon dioxide equivalent. A 1% annual increase in RAP use nationally reduces 0.14 million metric tonnes of GHG emissions, equivalent to removing 30 000 cars from the roads in a year.

The positive impact of RAP use from 2009 to 2020, according to the EPA’s Greenhouse Gas Equivalencies Calculator, is equivalent to the amount of carbon offset by planting 388 million tress and letting them grow for 10 years. “Our efforts are akin to planting a tree for every man, woman and child in the US,” said Copeland.

“That’s only considering recycling. Imagine what our industry has achieved with all our energy and emission reduction efforts and technologies.”

Some technologies under investigation include quantifying the upstream impacts of additive production, new forms of asphalt binder and/or binder replacements, rapid assessment of new materials, education on use and acceptance of scope 3 emissions, performance tests leading to specification development that encourages innovation, and research allowing industry to increase RAP content to greater than 40%.

The US industry is looking to achieve resilience by using tools already available and expanding that toolbox. A few of those tools are rapid construction techniques that can lead to rapid recovery, pavements designed for longer lives, climate adaptable materials designed to handle extreme temperatures, WMA allowing for increased haul distances, porous asphalt to manage stormwater, deep reconstruction with full depth reclamation, and cost-effective ways to strengthen pavement bases with asphalt overlay.

“Natural and nature-based features are paramount,” said Copeland. “Don’t design against nature; design with nature.”

Focus areas

Copeland’s words align closely with SAT’s strategic direction in South Africa and the call to action by its growing membership of asphalt and related practitioners.

This was mirrored in the focus areas of SATBinderrr 2022 – Asphalt, Seals, Pavement Design and Binders representing the core of the asphalt and bitumen sector, and three additional focus areas, Recycling for Flexible Pavements, Chemistry for Roads, and Industry Disruptors, all directly associated with sustainability and resilience in the industry.

The focus areas were chaired by young professionals, who managed their portfolios and the topics presented with energy and passion outside of their day-to-day jobs.

Nishaat Mowzer, associate at Zutari and chairperson of the Seals focus area at SATBinderrr 2022, commented that the presentations were very relevant and well put together by the mainly young presenters.

“There were some very innovative and interesting topics shared, for me, particularly around the bubble rising in seals with entrapped moisture in old surfacing and the need for a new test/spec for resealing after wet conditions, as well as the unexpectedly good performance of new-age modified emulsion slurries, and the work to improve the adhesion properties of anionic emulsion.”

Sponsors

The fact that SATBInderrr 2022 secured no fewer than 17 sponsors is testimony to the esteem in which this fledgling event is held.

“It was a privilege to be involved in the SATBinderrr 22 conference,” stated Bennie Greyling, managing director of headline sponsor AECI Much Asphalt.

“SAT has achieved its goal of creating a platform for young professionals to share their research and experience, and to grow their professional careers in doing so. The delegate profile also painted a bright picture for the future of the road engineering profession, with good representation from young professionals from all walks of life.

“The second SATBinderrr conference built on the good foundation of the first one and it is clear that the conference will grow from strength to strength and become a prominent date on the annual conference calendar,” Greyling concluded.