A whole life issue

One of the key factors in assessing sustainability is measurement of CO2 emissions. But there is more to saving the environment than measuring carbon footprint, argues Asphalt Industry Alliance chairman, Colin Loveday.

Sustainability has become the watchword across a number of industries and not least within the industry that supplies the asphalt that makes most of the country’s roads. All of the asphalt companies that are members of the AIA have their own sustainability programmes and these extend from power savings throughout the production process to responsible sourcing and the development of new technology such as lower temperature asphalts.
Collectively, the asphalt industry has demonstrated its commitment to the issue by embarking on a collaborative three-year research programme, due to be completed in 2011. The research underway at TRL involves the Highways Agency, which also co-funds the programme along with its project partners the Mineral Products Association and the Refined Bitumen Association. Its aim is to produce a sustainability management system for the highways sector.

Calculating carbon

Greenhouse emissions were first on the agenda and an early positive result from the programme was the emergence of a carbon footprint calculator for asphalt products. Known as asPECT, this has been welcomed as a major industry initiative. Although most asphalt producers already had their own means of measuring CO2 emissions, these naturally varied from company to company, making it quite difficult to compare accurately the carbon footprint of different products.
This new web-based tool provides a standard protocol that gives specifiers for the first time the means to compare the carbon footprint of any asphalt product on an equitable basis. More important, the steering group for the project involved experts from industry, from the Highways Agency, local authorities and WRAP to ensure that it best answered the needs of those who had clearly indicated the urgent need for such a tool.
Essentially, asPECT is a three-part tool, comprising a protocol defining the boundaries of carbon footprint calculation, calculator software and a user guide. The tool is easily available via the TRL website and has been in use since the beginning of the year, with feedback helping its further definition and improvement.
In parallel, asphalt producing companies are competing for the lowest carbon footprint, individually implementing their own sustainability programmes.

Asphalt benefit
A major benefit of asphalt is that it can be 100 per cent recycled as asphalt. The material from worn or aged roads can be reprocessed into fresh asphalt for use in maintenance and construction. By doing this, around half of the embodied carbon from the first application is saved and reincorporated in the second life. The goal now is to increase the percentage of re-used material in surface courses. A new benchmark has recently been set on an M25 project, which saw the highest ever percentage – 40 per cent – of the surface course constituted by recycled asphalt pavement.
The advantages of more sustainable asphalt extend beyond the production and laying of the material itself. Ultra-thin surfacing material can provide numerous benefits including reduction in spray and noise, improved surface friction, excellent lateral drainage properties and durability. Faster installation times are possible and there are fewer lorry deliveries required, so site works are less intrusive to the environment.
The industry has for a long time focused on durability, on the simple premise that doubling useful life will halve resource consumption and carbon emission. New asphalt products using high performance bitumens can provide enhanced durability at all levels in the road structure. As climate change brings (with some obvious exceptions) generally warmer, wetter winters and wetter summers, as witnessed by recent dramatic flooding, water has rapidly become highway enemy number one. The industry has developed long life, high bitumen content water resistant bases and surface courses, linked to new bonding techniques to future proof our roads against the expected climate change. High performance bitumens also increase structural strength and reduce wheel-rutting caused by large volumes of heavy traffic.
There is now industry-wide development of asphalts that can be mixed and laid at lower temperatures while retaining similar benefits to traditional hot mix asphalts. Significant reductions in burner fuel used in production are possible giving equivalent savings in overall carbon emissions. Another notable benefit of laying asphalt at lower temperatures is that vehicles can be allowed onto the new surface more quickly, so there is less traffic disruption and therefore also environmental impact of the resurfacing works themselves.

A valuable asset
These are just a few of the ways in which AIA members are moving the industry both collectively and as individual companies to significantly reduce its overall carbon footprint. We have made huge progress over recent years: finding an industry event without the topic of sustainability high on its agenda would probably now be a challenge.
The irony is that while the supply sector does its utmost to innovate, driven by demand from customers anxious to ensure they are providing the most sustainable roads, all efforts are thwarted by the challenge of keeping our roads well maintained. Earlier this year the news was full of pothole counts, not just from the AIA’s own ALARM Survey but from various sources across the country reporting on the disgraceful state of our roads and the resulting monumental costs of damage.
Roads are our largest and most valuable asset and one on which practically all other services rely. Apart from the sheer common sense of protecting this asset and keeping it in reasonable fit-for-purpose condition, the environmental impact of not doing so negates everything else the industry is doing to provide a sustainable road network. Forcing vehicles to drive on uneven, potholed, badly maintained roads can only increase their fuel consumption and, with it, overall carbon emissions.
With non-ring fenced maintenance budgets from central government, the highway maintenance service has traditionally been an easy target. Over the last few years realisation appears to be finally dawning that under-funding this service is a false economy. The potholes that were revealed as the last of this winter’s snow melted were too obvious and numerous to ignore. Who can possibly argue that allowing our roads to deteriorate to the extent where, as one local authority highway engineer put it “we’re simply rushing around throwing asphalt into holes” is an environmentally responsible approach?
We have a new government, one with a new approach to governing. Let us hope that it will also take a new approach to protecting our road system and ensuring its sustainability.

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