the following sections are selected from the column of "national memory - half a year span of nanjing yangtze river bridge".
at the beginning of the bridge construction, in order to reduce the self weight of the bridge deck and save steel, the leaders of the bridge bureau of the ministry of railways at that time proposed to reduce the weight of each cubic meter of concrete from 2400 kg of ordinary concrete to 1600 kg, and to reduce the weight of the wall panel by one third. this task was completed by a group of young people who graduated from university in that year.
song shaoming, then 26, is the deputy leader of the research team. in 1959, he came to nanjing with a group of young people to develop and produce lightweight concrete for the main bridge deck.
song shaoming: at that time, we were involved in six or seven majors: material, chemical, structural, economic, construction and concrete technology.
luo jianan: very thin data. this is the only data that we used to do scientific research at that time. on this basis, we began to explore and work out.
after nearly five months' hard work, these young people broke through the subject of "experimental research on structure and technology of sintered clay ceramsite and ceramsite concrete".
song shaoming: finally, he decided to use clay to burn ceramsite. what is ceramsite? it is a kind of clay that softens under high temperature. once softened, its gas will not run out in the ball, and it will be wrapped in the shell and become a very light particle to replace the stone.
in 1960, the former ministry of railways held an appraisal meeting in nanjing. a 40 ton crawler crane drove past the suspended ceramsite concrete bridge deck. song shaoming and his colleagues stood under the inspected bridge deck and wanted to see the inspection results of their works.
song shaoming: we don't feel at ease. we also need to look at this wall panel. can we make the bridge panel? so we also want to have a look. we didn't expect how dangerous it was at that time.
the appraisal result is very good, the weight of ceramsite concrete pavement is 0.5 tons less than that of ordinary concrete per square meter, and nanjing yangtze river bridge is fully used.
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