Engineers have long debated between asphalt and concrete for roadway projects. Choosing between the two materials means weighing cost-effectivity, durability, maintenance, and eco-friendliness.
Carried by the momentum of the government’s flagship infrastructure program ‘Build, Build, Build,’ engineers in the Philippines must face the question more frequently: which surface is superior for roads and pavements?
The price difference between concrete and asphalt varies per project. Asphalt is the cheaper choice when it comes to preventive maintenance, with costs up to 20% less than concrete. But when it comes to construction of new roads and rehabilitation of existing ones, concrete is the cheaper choice by up to 16%.
It’s also important to note that concrete has to be cured for at least a week before being used, while asphalt surfaces can be used in a day (or even less); a key consideration for projects like public infrastructure, where it’s crucial that roads have to be opened for traffic as soon as possible.
Durability and efficiency
Under extreme pressure or surface movement, concrete will crack faster than the more flexible asphalt. Repairs for this can get very expensive — sometimes even the whole slab would need to be replaced in case of more significant cracks — but concrete’s superior durability means breaking can be a very rare incident. But this durability is put to the test in climates with freeze and thaw cycles. Concrete can deteriorate faster over time with the fluctuation of moisture and extended exposure to salt and de-icing compounds.
For the Philippines’ tropical weather, it can feel hotter than it should be with asphalt surfaces. The material absorbs sunlight as heat and can radiate it back, and can embrittle faster than concrete during summer.
As asphalt expands and contracts under the weather, it requires more frequent maintenance through patching and sealing — the first one is done six months after installation — while concrete demands less upkeep other than resealing every 5 years.
Longevity and sustainability
Concrete’s longevity is its key edge over asphalt. With the correct maintenance, it can reach almost double the average lifespan of an asphalt road, which is 15 to 20 years.
Both materials are highly recyclable. Asphalt is the most recycled material in the US and rarely ends up in a landfill, while concrete pavements are also 100% recyclable. But regardless of production or recycling, greenhouse gasses are still released into the atmosphere in melting asphalt.
There’s no quick or easy choice between concrete and asphalt. Both materials have qualities that could be a good fit for different situations, on top of existing considerations in funding, function, climate, and location.
Empower your decision with up-to-date international standards and the decades of expertise of Glynn Holleran, who will be leading the CPD-certified Pavement Design, Construction, and Rehabilitation of Roadways Masterclass on February 19 & 20, 2020 at the Manila Elks Club, Makati.
Holleran is an internationally-renowned materials chemist and engineer with over 40 years of experience in infrastructure projects all over the world.
Join the course and know more than just choosing the right materials for your project: learn advanced methodologies in surfacing design, roadways assessment, pavement preservation, and more.