Another memorable part of his career was using rubber asphalt made from discarded waste tires to pave the roads in the Chongming-Qidong channel project. Yuan said that this alternative material helped to lower noise levels and enhance traction on the roads, and was important in reducing the impact of waste tires on the environment.

Today, almost all the workers in the first batch of paving jobs in Shanghai have retired except for Yuan.

"I have decided to train one or two apprentices before I retire, imparting my skills and experience to them so that they can contribute to the city's construction needs," he said.

Gong Qianqi in Shanghai contributed to this story.