HOW HIGH-SCIENCE AND ROADWORKS COLLIDE

Mitchell Keller looks ahead at the future of road construction, as science and technology are set to give the segment a big boost

Talk to anyone who has spent a career in the roadworks industry and there’s more often than not a buzz of excitement behind their words when discussing the future. There’s a good reason for this as, over the last 100 years – even though machines, materials and methods have improved – road construction has largely looked the same and produced similar results, but that is beginning to change.

Modern road projects are entering a new era, and clients are expecting increasing accuracy, efficiency and autonomy. The industry is expected to evolve along with these and sustainability/emissions-reduction goals, but to answer the call, road builders are spending more time than ever in the laboratory researching how today’s modern materials can be applied with hyper-efficacy using novel machinery.

The end game is to identify all the science behind [road works] from batching to what’s designed in the laboratory and taking a lot of the variability out of the process

Making machine learning a reality

Unlike other construction segments, road works have a unique opportunity to develop highly advanced machine learning sooner than later. Autonomous and semiautonomous solutions are more applicable to the fixed and horizontal nature of the world’s streets, avenues and motorways.

Paul Jaworski, product manager at USbased Minnich Manufacturing, a drilling and vibration specialist equipment manufacturer, notes his firm will be spending more time over the next five years in research and development (R&D). He tells International Construction the gains from machine learning and autonomy will be huge for road building.

“The main pieces of what is being developed for the next five years are ongoing research projects that we’re involved with for machine learning, more heavy machinery – basically looking at all the functions of it from both sides of the equation, from the mix design side and the actual operator side of the machine,” he says.

Jaworski says Minnich is also supporting universities that are studying every aspect of road construction and how it can become more economical. “The end game is to identify all the science behind [road works] from batching to what’s designed in the laboratory and taking a lot of the variability out of the process,” he comments.

Minnich Manufacturing’s AV-CC II telematics system, which can monitor up to 48 hydraulic vibrators during the paving process

Workers level asphalt

IMAGE: ADOBE STOCK

“We’ve been looking more into the sustainability and durability issues of it. So, as it goes out into the future, all the processes from both the design side of the mixtures to the execution on the paving machines and make it as autonomous as possible.”

One major challenge: making sure today’s road building processes and machines are equipped with the right tools and tech for novel concrete and asphalt products.

Jaworski relied on his perspective as board chairman of the American Concrete Institute (ACI), a US-based technical society and standards-development organisation, to illustrate the challenges.

Referring to the ACI’s design code and construction specification standards, Jaworski said – by needing to keep up with modern mixtures and emissions reduction goals – that the most recent standards document was “gutted” to make way for new specs.

“Those specifications reflect more of a carbonneutral practice, now, and you’re going to see more and more carbon neutral construction practices,” says Jaworski, adding the cementheavy road works industry should expect ample change in this sector going forward.

“It’s always been the materials. When you’re looking at saving carbon and saving cement, you have to look at wasteful practices and the actual put-down of concrete.”

In other terms, even though ‘putting down’ concrete will still look the same in five years, it will be a completely retooled process starting with its production. “Basically everything” will change, says Jaworski.

Sumitomo’s HA60C asphalt paver in action

IMAGE: SUMITOMO

All this R&D will essentially create a reliable source of data and information, which is the basis of machine learning and autonomy breakthroughs.

When these strategies are coupled with advances in concrete and asphalt sensors (like products from Hilti, Doka or Humboldt Manufacturing), the hope is a future where batching, delivery, and road building are nearly automatic (and able to deliver quality in any given region at any temperature), with labourers on-site to manage machines, not necessarily lay material.

“We’ve got to first run trials through those similar situations. We’ve got to get the data from a 60-degree day, then we need to do it on a 70-degree day,” Jaworski notes.

“It takes a long time, at least initially, to make those data lakes. I’m finding that data is just now starting to fill up these reservoirs.”

Strabag trialled the autonomous asphalt paver on a section of the A9 near Graz in Austria

IMAGE: STRABAG

Lack of workers drives innovation

In Japan, Sumitomo Heavy Industries – which manufacturers pavers, rollers and other road construction machines – notes that a suppressed labour market has been driving their innovation in autonomy.

“[The] working population continues to decline year-by-year due to the low birthrate and aging population in Japan. Particularly in the construction industry, the aging and retirement of highly skilled workers – also low retention/high turnover rate of young workers – has led to a serious shortage of labour and a decline in skills,” Sumitomo tells International Construction. “This trend is expected to continue in the future.

“On the other hand, Japanese paving sites are so concerned about quality that a large number of workers is required besides machine operators who prepare edges of pavement, fix uneven areas, etc.,” the company continues. “For those reasons, it will be difficult to secure these workers in the future, and it is important to increase productivity at the paving site to maintain the existing quality.”

The firm touted developments in automatic screed extension and retraction, as well as automatic steering. “When steering is automatically controlled, straight line connecting the centre positions of the difference is used as centre line of machine’s travel,” explains Sumitomo.

This process eliminates the need for total stations and 3D measuring instruments, which the company says reduces installation costs and eliminates the need for 3D design – further reducing need for human resources and manhours.

Some autonomous ideas are getting tested in the field. Near the Austria/Slovenia border, Austria-based construction group Strabag recently trialled an autonomous asphalt paver on the A9 motorway.

The paver laid the asphalt on the 180m-long trial section completely autonomously, with implementation and logistics coordinated by a Strabag team from Graz, Austria.

The system uses a special module for autonomous control of the machinery. It is connected directly to the digital interface of the asphalt paver and feeds the machine target data for the paving section. The machine also features object recognition sensors and satellite navigation (GNSS) to keep it on the right course.

The unit includes a newly developed paver attachment that integrates a sensor-equipped fibre optic cable directly into the surface course during paving. Along with temperature and movement sensors, tech feeds the machine information about the load on the asphalt during use.

Sebastian Czaja, head of TPA Group PSS (Process Stability in Road Construction), says, “In the future, paving staff will increasingly be performing the task of controller. They will be able to work at a greater distance from moving traffic, keeping them less exposed to vapours and aerosols during the paving process.”

Electric adoption still slow

A question of what will power the road construction machines of the future remains elusive. While electric machines, in theory, seem like a good fit for road works as electrification and autonomy tend to go hand-in-hand, there’s an energy access issue: some roads are remote, projects can be dozens of kilometres long (and longer), and safety and space are paramount. All that considered, it means dieselpowered machines have been more reliable and affordable for road builders despite the electric evolution. Over the last five years, manufacturers have started producing larger ranges of battery-powered heavy equipment designed for road building, but very few are used. Recent estimates suggest electric road construction machines represent around 1% of the market for roadworks machinery sales. Part of the adoption problem is a global patchwork of expectations. For example, in Europe, where material and sustainability regulation have historically had more teeth compared to the US market, some emissionsfree equipment has penetrated the sector. Sweden-based Volvo Trucks provided Mexican cement supplier Cemex with its first fullyelectric and zero-exhaust emission heavyduty concrete mixer truck. The aggregate/ material provider first used those trucks at its Berlin, Germany, ready-mix site. As recently as October 2024, Cemex launched electric vehicles in Mexico, with additional plans to use them across Europe.

Cemex is also using the recently launched electric slipform paver from a collaboration between Switzerland-based tech firm Leica Geosystems and South African infrastructure machinery supplier Roos Groep.

A fleet of machines on a modern road construction site

IMAGE: ADOBE STOCK

Yet Ben Rawding, general manager of government and municipalities at UK-based JCB, says even though his company has been marketing battery-powered road-building equipment since 2018, the higher cost of electric machines is still proving to be a barrier. “We have been focusing on sustainable practices, but one of the major challenges in the industry is the cost,” he says.

JCB is not alone in worrying about the difficulties of getting more industry adoption of battery-powered machinery, which can cost as much as twice the amount of a diesel alternative.

Seby Joseph, global marketing manager at Dynapac, says that recent falls in government subsidies for battery powered equipment makes it a harder sell. Dynapac announced its first battery-powered electric roller more than one decade ago, and has expanded its batterypowered road-building equipment range to include compactors, pavers and vibratory plates. But the 13 years of presence doesn’t change the financial limits for end users. “There is no motivation for companies to buy anymore because this equipment, from a purchase-price point-of-view, can cost anywhere from 1.5 to 2.5 times the diesel equivalent,” says Joseph.

“The initial investment is a major concern for companies. The cost is the primary driver of this initial investment. The use of new technologies in the battery and the low volume levels results in higher costs for us to build this equipment.”

Battery-powered prototype

In May 2024, Sweden-based machinery manufacturer Atlas Copco, unveiled the prototype of its first battery powered industrial air compressor designed to solve the problem of accessing a power source for the tools needed in road construction when machinery is constantly on the move.

Maarten Vermeiren, vice president of marketing for the portable air division at Atlas Copco, says the B-Air 185-12 is the world’s first mobile screw compressor powered by a battery and is currently in production.

Vermeiren says that, so far, the market response to the new machine has been mixed, with potential customers in some European customers put off by the price.

THE PROJECT USING ‘LESS POLLUTANT’ ASPHALT

Strabag has said that it’s using an ‘air-purifying’ and ‘noise-absorbing’ asphalt for road works on Erbschlöer Straße in Wuppertal, Germany. Called Clean Air Asphalt, stylised ClAir for short, Strabag said it is renovating the surface course of a 1km stretch of road with a total area around 11,300m2 .

The company added it’s the largest ClAir project to date of the 20 pilot routes executed to date. ClAir was first launched in Germany in 2019.

“The Strabag team from the North Rhine-Westphalia Directorate has installed a total of around 1,100 tonnes of Clean Air Asphalt on Erbschlöer Straße, which is around 11m wide, with the company’s innovation manufacturer,” said Strabag. “Previously, the construction site team of the Rhineland… milled off the old asphalt layers and renewed the binder course since 29 July, first on the uphill side of the road, then on the downhill side of the road.” The material relies on titanium dioxide (TiO2 ), which produces a photocatalytic effect that ultimately helps reduce nitrogen dioxide (NO2 ) under ideal conditions (ample sun, little wind). TiO2 is a mineral which exists naturally in sands, soils and other minerals, but can also be synthetically produced from natural ores like ilmenite and rutile.

Strabag said TPA is using a complex method to track NO2 emissions and noted noise-reduction applies after installation.

ClAir Asphalt paving with the Strabag innovation paver in Erlangen, Germany

IMAGE: STRABAG

The GOMACO CC-1200e all-electric slipform paver

IMAGE: GOMACO

“The price of the battery-driven compressor is a major factor; it is significantly more expensive than diesel-powered compressors, which makes it difficult to convince customers to switch,” he says. “In the Netherlands and Norway, where electrification is more advanced, it is easier to make a business case for the battery-driven compressor. However, in other countries, it’s harder to justify the switch.” In North America, Patrick Zanen is global director of business development at US-based machinery manufacturer GOMACO, which launched a battery-powered slipform curb machine in 2021. He notes that finding a global standard for road building could be advantageous for OEMs, but also says his company is planning ahead, regardless. “There are different government perspectives on roadbuilding and sustainability,” he acknowledges. “From my years in the road construction machinery business, I’ve observed that it’s very much a business-driven model tied to financial aspects. Budgets play a key role in driving developments.”

Furthermore, conflicting standards from continent to continent and country to country make it difficult for even global firms to keep up with standards.

“It is not feasible to create machines tailored to each country,” says Zanen. GOMACO, he adds, is responding with an innovation of its own. “We’ve developed a modular concept to meet diverse requirements and build sustainable roads based on different specifications worldwide.”

Predicting the digital future

EUPAVE, a not-for-profit concrete paving association in Europe, predicts that future technical innovations and digitalisation will drive sustainability in the road-build industry, with IOT (internet of things) devices enabling construction and maintenance crews to assess their work and find out exactly when roads need repairing.

“The use of sensors is becoming more and more commonplace in construction; in road building, it is slow in coming, but this is bound to change,” says Luc Rens, managing director at EUPAVE.

“Modern sensors and communication tools provide answers to many questions: by measuring time and temperature and, thanks to concrete’s maturity function, strength development can be continuously monitored, and action can be taken at the right time.” Shrinkage, moisture content, electrical resistance of the concrete in the mass and at the surface and thermal movements can also be measured.

Rens says that with this information bundled in a ‘digital twin’, the industry should be able to monitor, assess and optimally manage the structure during the construction and operational phases.

A tool like AI will inform digital twin managers in road construction the same way they might with a building: data collected will create a model, which can be accessed and annotated by multiple stakeholders and, ultimately, delivered to the client or owner for perpetual management.

It’s somewhat complex stuff for a relatively consistent industry, but the energy is palpable. Driven by both inside and outside expectations, the next stretch of time may just be some of the most productive in road construction, yet. iC

WIRTGEN GROUP WIDEN URUGUAY’S RUTA 5

Wirtgen Group, a John Deere company, says progress on the Ruta 5 improvement project is well underway, and shared some of the details in a recent job report.

“Up to now, there has only been one lane in each direction. But now, the northbound and southbound lanes of a 75km section of the highway are being doubled to two lanes,” says Wirtgen.

The project involves constructing the new lanes and rehabilitating the existing road surface of Ruta 5, one of five major motorways in Uruguay.

According to Wirtgen, four contractors were commissioned to carry out the construction project: INCOCI, R&K – Berkes, L.P. Pietroboni and Stiler.

The company adds that Interagrovial attended to the needs of the fleet, which includes three Wirtgen SP 64 slipform pavers, three texture curing machines (TCM 180), and a number of other machines. Unique to the build is said to be the use of a dowel bar inserter (DBI) on the SP 64.

“When constructing concrete roadways, the reinforcement in the form of dowel baskets or steel rebar mats is frequently pre-placed ahead of the machine. The pre-placement process considerably limits the space available on the construction site and hinders the manoeuvring of construction vehicles on the site,” says Wirtgen.

“Both the dowel bars and the longitudinal tie bars are placed automatically across the entire paving width. The concrete can be offloaded and evenly spread immediately in front of the machine. Construction vehicles such as the tipper trucks supplying the concrete have more space to manoeuvre.

“This increases process reliability, as the dowels and tie-bars can always be inserted at exactly the right locations.” All tools combined, Wirtgen says the site was easier to manage and monitor.

A Wirtgen Group slipform paver and texture curing machine work a road build in Uruguay

IMAGE: WIRTGEN GROUP