More special bricks in Beijing to absorb water
Updated: 2012-09-30 18:00
BEIJING - The Chinese capital plans to lay more water-absorbing bricks this year in the urban area to conserve rainwater and alleviate the so-called "heat island effect" meanwhile.
"Compared with roads paved with cement, rainwater goes down to the earth more easily through such bricks," said Wang Hao, an academician with the Chinese Academy of Engineering.
He said such bricks will help to alleviate flooding during the rainy season, save water for the sunny days, as well as moderate the "heat island effect", referring to the phenomenon that temperatures are often a few degrees higher in cities than they are in their surrounding rural areas.
According to the Beijing Water Authority, 150,000 square meters of water-absorbing bricks will be laid this year. These bricks will join around 1 million square meters of such bricks already laid in the city..
Wang Hao said that water-absorbing bricks could retain at least 40 percent of the rainwater, instead of letting nearly all of them flow away through the drainage system.
"In sunny days, the water retained this way could cool the temperature on the ground in the process of evaporation," he said.
Water-absorbing bricks, which cost 30 yuan to 100 yuan per square meter, have been used on sidewalks, in parks, campuses, and some residential areas of Beijing.
Qin Shengyi, chairman of the Beijing-based Rechsand Science and Technology Group, said the company has developed a brick that could retain 80 percent of the rainwater, using sand from deserts as the key raw material.
Qin said the company sells millions of square meters of water-absorbing bricks each year.