TOKYO - Road cave-ins are occurring one after another across Japan. According to a survey released on April 22 by the Ministry of Land, Infrastructure, Transport and Tourism, so-called dangerous sewer lines requiring urgent countermeasures now total 748 kilometers nationwide.
How can such a vast number of deteriorating sewer pipes be repaired? Reporting on the ground shows private-sector companies are turning to advanced technology for solutions.
Footage from inside a sewer pipe running beneath a residential district in Saitama Prefecture reveals severe damage.
More than 30 years have passed since installation. Concrete walls that were originally about 40 centimeters thick have been corroded over many years by hydrogen sulfide generated inside the pipe. Reinforcing steel bars are now exposed.
Applied to these damaged walls is a white new material developed by Someq Technology, a company engaged in paint development and manufacturing.
Using technology that reduces coating particles to nano size — roughly one millionth of a millimeter — the company created a material unlike conventional paint. Because the particles are extremely small, they adhere tightly even to surfaces filled with holes and unevenness. The company says the coating not only restores appearance but also improves structural strength beyond the original level.
A simple demonstration highlighted the material's performance.
A chair made from ordinary cardboard was coated with the new material. Once treated, it was strong enough for a person to sit on and stand on.
The resulting strength is said to exceed that of concrete by more than 20 times.
Replacing sewer pipes with new ones has been the standard approach. But this method requires only coating existing infrastructure, sharply reducing both repair time and costs. The application process also does not require highly specialized skills.
Sadao Hishiki, president of Someq Technology, said making the technology usable even by less experienced workers was a major development goal. He added that contributing to society gives the company a strong sense of purpose.
Source: TBS
