24 Apr 2018
Asphalt has long been used in road construction. While developments have been made since it was first used, problems with its lifespan and susceptibility to cracks persist.
Now, Abd El Halim has introduced his Asphalt Multi-Integrated Roller (AMIR) as a solution to the issue. The Transportation Engineering Professor from Carleton University, Canada, says the new machinery could reduce the likelihood of potholes and extend the life of roads.
The arguably outdated current method involves three rollers – the next smaller than the previous to achieve finer compacting. Construction workers have to roll over the asphalt up to 20 times to reach the desired effect with this machinery.
‘We’ve used the same rollers for 200 years,’ said Halim. ‘We’ve changed everything else you can imagine – the mix, the traffic – but it’s the same rollers.’
Even the initial paving method can cause cracking, as repetitive rolling causes vibrations and pressure that can disturb the asphalt. ‘After the appearance of a crack, there is no way you fix them,’ said Halim.
The AMIR technology is one wide rubber belt that is in constant contact with the road. The process need not be repeated more than eight times – significantly reducing the likelihood of cracks.
Halim’s method has undergone a trial in Ottawa, Canada, where, so far, the AMIR-built roads are crack-free. Industry has collaborated with Halim to convert current rollers in the sector into AMIR versions.
Initial results are promising, and Halim hopes that with more work, the AMIR method can pave roads that will last 20 years instead of the current seven.
‘Asphalt is a flexible material and it is always going to develop cracks over time,’ said Tony Cecutti, General Manager of Infrastructure Services in Greater Sudbury, Canada. ‘There’s no way to avoid that. The older your road is, the more cracks are going to occur in it. That’s why areas where we have the most potholes tend to be the older roads.’
If successful, the technology could prove extremely popular in the Northern Hemisphere, with cold climates known to damage roads. When asphalt comes into contact with water, it fills the existing tiny cracks in the road. It then freezes and when the thaw occurs, the cracks get bigger, which eventually leads to potholes.
Cecutti says fixing potholes is one of the most expensive processes for his city council, and he is not alone. It is estimated weather conditions in Canada last winter led to the creation of more than 150,000 potholes.
The AMIR method could solve that. ‘Everyone’s a winner,’ Halim said.
Asphalt – The road ahead
On Wednesday 6 June 2018, SCI’s Construction group will hold ‘Asphalt – The road ahead’ – the second in a series of conferences held by the group to discuss the forthcoming developments and issues for the use of asphalt to meet ever increasing demands for performance, value and sustainability. This one-day event will be held at the University of Nottingham, UK.
By Georgina Hines