PC: Public Works Authority ('Ashghal') in Qatar
Public Works Authority Ashghal has completed a pilot of cool pavement on roads in Qatar. The authority announced the work on 19 August 2019. An asphalt-cooling material was applied to up to 200 metres of vehicle lanes on Abdullah bin Jassim Street, beside Souq Waqif, and to 200 metres of pedestrian and bicycle paths in front of Katara, the Cultural Village.
According to an official from the Public Works Authority ('Ashghal') in Qatar, conventional asphalt absorbs up to 80 to 95% of sunlight, while the new coating reflects about 50%. Sensors will compare its temperature with conventional asphalt over an 18-month study, carried out with the Japanese company Oriental.
Why is Qatar painting some roads blue instead of black
The pilot used an asphalt-cooling material on parts of Abdullah bin Jassim Street, next to Souq Waqif.
The authority says it was applied to vehicle lanes over a length of up to 200 metres. The same material was also tested on 200 metres of pedestrian and bicycle paths in front of Katara, the Cultural Village.The road was opened to traffic so that testing could begin. The authority says the aim is to measure how effective the material is and to judge whether the experiment succeeds. It adds that the result could lead to formal use of the material across the road network in the State of Qatar.
How long will Qatar’s blue road study last
Ashghal says the study will last 18 months. Based on the outcome, the authority will decide whether the pilot has succeeded and how widely the material could be applied. The announcement says road experts and contractors have installed special devices and sensors on the pilot sections.According to Ashghal, these sensors measure how well the material reduces asphalt temperature and compare the results with conventional asphalt.
The authority says the work was carried out in cooperation with the Japanese company Oriental, which it describes as one of the leading companies in implementing this technology.
Why does conventional asphalt absorb up to 95% of sunlight
Ashghal explains that conventional asphalt contributes to rising temperatures because it absorbs up to 80 to 95% of sunlight. Cool pavement, the authority says, reflects ultraviolet rays and absorbs less solar radiation. Ashghal adds that this can have a positive effect on overall temperature reduction, given the size of the areas covered by conventional asphalt.On the specification, Ashghal says cooled paving material can be made from traditional paving materials such as concrete. The authority says the new coating on the concrete asphalt layer reflects "about 50% of sunlight". It states that the coating consists of four layers: a primary layer, followed by three consecutive layers that reduce the heat absorbed from solar radiation.
How does Qatar’s cool pavement improve road safety
The announcement says a protective material has been applied to the ground markings.
According to Ashghal, this shields the markings from contact with vehicles and increases their lifespan. The authority links cool pavement to energy efficiency and says research by environment and sustainability experts suggests it can reduce overall temperature and, as a result, emissions.Ashghal also cites research suggesting that cool paving material reduces heat-related illnesses and slows the formation of smog. The authority says it can improve pedestrians' ability to use the road and promote traffic safety, because light-coloured pavements reflect street lights and car headlights better and make vehicles more visible to drivers. In addition, Ashghal says that lowering air temperatures in residential areas can slow the chemical reactions in the atmosphere that cause smog.