BEIJING, Dec. 6 (Xinhua) -- Chinese researchers have developed a new type of concrete with self-cleaning ability, according to a recent study paper published in the journal of American Chemical Society Applied Materials and Interfaces.

The outer wall surfaces of modern buildings are commonly washed by people suspended in air using ropes. The researchers from the School of Chemistry and Materials Science of the University of Science and Technology of China hoped to find new materials that can conduct self-cleaning as well as provide excellent heat and sound insulation.

The concrete exhibited remarkable hydrophobicity with a water contact angle of 166 degrees both on the surface and inside of the sample, signifying remarkable stain repellency and long-term stability, said the paper.

The water contact angle remained unchanged under continuous mechanical grinding and harsh environments, such as high temperature and chemical erosion.

A controllable porosity from 56.3 to 77.4 percent and homogeneous small pore size give the concrete high compressive strength and low thermal conductivity.