LAN 40 No 5:Layout 1
12/03/2022
11:09
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Go Green with Colas! In February of last year,, Gearoid Lohan, CEO of Colas Ireland, launched a “Go Green with Colas” initiative to encourage all Colas subsidiaries to play a more pro-active role in meeting their environmental responsibilities. An additional aspect of this initiative is to raise awareness with our many customers and stakeholders of how Colas can help them meet their carbon reducing targets. In March last year, Irelandʼs carbon reduction targets were enshrined into law by the Government when it passed legislation committing the country to an overall aim of reducing our carbon emissions by 51 % by 2030 and to reach “net zero” by 2050. These are ambitious targets and will require action and contribution by every sector of industry and community. Since its establishment over 70 years ago, the Colas Group has led the way in the development of environmentally friendly pavement materials. In fact, the name Colas comes from the words COLd ASphalt. Cold-mix asphalt, as it is called, is similar to the more commonly used “hot-mix” asphalt but is produced by using a bitumen emulsion instead of the conventional hot bitumen. As bitumen emulsions can be used with aggregates at ambient temperatures, as opposed to the high temperatures required to manufacture hot-mix asphalt, there are considerable energy and, hence, carbon savings to be achieved by their use.
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Figure 1: Cold-mix asphalt trial in Colas yard in Mallow, 1984
Colas first introduced the cold-mix asphalt technology into Ireland in the 1980ʼs. In 1990, a cold-mix asphalt called “Grave-émulsion” was used in the base course of a 40 km section of the N8 from Dublin to Cork. At that time, the N8 was the highest trafficked road in the country. But the grave-émulsion cold-mix material well and truly survived the test of time. In fact, when it had reached the end of its design life in 2006, there were no signs of distress or failure, with no cracking, an average rut depth of only 3 mm (versus the failure criteria of > 10 mm) and an IRI smoothness indicator of 1.7, which is well below the smoothness criteria for a new road! Since then, Colas Ireland has led the development and promotion of other emulsion-based materials and techniques such as surface dressing, cold-asphalt micro-surfacing and in situ pavement recycling.
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