Air purifying concrete

[Thomas C]

Dutch town tests 'air-purifying' concrete (AFP) | Yahoo! Green


Dutch town tests 'air-purifying' concrete

Posted Wed Aug 6, 2008 11:24am PDT



A recent picture shows the special paving stone in a lab of the Twente University. A road in the small Dutch town of Hengelo is to be paved with air-purifying concrete in a trial that could lead to a breakthrough in the fight against rising pollution, scientists said.(AFP/ANP/File)

THE HAGUE (AFP) - A road in the small Dutch town of Hengelo is to be paved with air-purifying concrete in a trial that could lead to a breakthrough in the fight against rising pollution, scientists said Wednesday.
Experts from the University of Twente developed and tested the concrete paving stones which contain a titanium dioxide-based additive.
In laboratory conditions, the additive -- under the influence of sunlight -- binds the nitrogen oxide particles emitted by car exhausts and turns them into harmless nitrates.
"With one rain shower everything is washed clean," the institution said in a statement.
Nitrogen oxides, produced by industry and motor vehicles, are among the main air pollutants that lead to acid rain and smog.
Developed from a Japanese invention, the bricks are now being put to the test in Hengelo in the eastern Dutch province of Overijssel.
One half of a road under reconstruction is being paved with the new, green bricks, and the other half with the ordinary variety.
"By measuring the air quality in both areas, we will be able to show the efficacy of the bricks," said the statement.
Apart for their ability to clean the air and repel dirt from the road surface, there was no other difference between these new bricks and the old ones, the university said.
"The province of Overijssel sees an opportunity in these bricks to improve air quality," it added. "This trial project is of great significance for the entire country."
The road was expected to be finished by year-end.
The first air measurements will be taken early next year, with the first results expected next summer.