A trial of a carbon-neutral binder in asphalt in Hafnarfjörður

A landmark project in Iceland and an important step in the fight against carbon emissions.

Colas Iceland Ltd, in collaboration with its parent company, is participating in a research project currently being conducted worldwide. The project involves mixing an organic material, PTO, a by-product of the paper industry, into conventional crumb rubber, which is used for mixing asphalt, among other things, in Iceland. The City of Hafnarfjörður is participating in this groundbreaking project in Iceland with Colas, and asphalt containing the aforementioned binder has been produced and laid on a new footpath on Ásvallabraut in Hafnarfjörður.

Mayor Rósa Guðbjartsdóttir with representatives of the City of Hafnarfjörður and Colas at the aforementioned footpath.

Carbon neutrality and even a negative carbon footprint

With this new blending, the conventional cut-back bitumen is softened and its important properties are altered. The depth of cut, which is a measure of stiffness, increases, but the softening point decreases. In Iceland, two types of bitumen are used for asphalt production, colloquially referred to as hard bitumen and soft bitumen. When PTO is mixed into the „hard bitumen“, the bitumen softens and its properties become similar to those of the „soft bitumen“, which is the type used most commonly in the country. The most important thing about this project is that, due to its origin, the PTO contains Negative carbon footprint, so negative in fact that with 12% incorporation, the mixture, that is the binder used in the asphalt, is carbon-neutral and even negative.

„Hafnarfjörður's green vision is reflected in its planning, policies and action plans, and lays the foundation for a comprehensive strategy for the municipality up to the year 2035. Participation in this pilot project with Colas is one of the many green steps the municipality is taking at the moment. We are the third largest municipality in the country and are fully aware of our responsibility in the bigger picture. We aim to be at the forefront of sustainability and environmental matters and to do our part in reducing greenhouse gas emissions and waste generation. This is a progressive initiative by Colas in partnership with the municipality,“ says Rósa Guðbjartsdóttir, Mayor of Hafnarfjörður.

An important step in the fight against carbon emissions into the environment

It is hoped that in the future the use of binders containing PTO in asphalt production will increase, which is an important factor in the fight against carbon emissions into the environment. By increasing the use of recycled asphalt in new asphalt, the asphalt industry is taking a major step towards its goal of a 30% reduction in CO2 emissions by 2030.