From his story:
Yet there are legitimate critiques of whether the HSR system makes sound economic sense and whether the Chinese government can afford such a massive construction project. The pace of expanding the system -- the Beijing-Shanghai line, completed after a mere 2.5 years, is expected to commence operations this summer -- has led to questions over the quality and safety of what's being built. In particular, a little-known technical issue of the material used for the track foundations, apparently something called "fly ash." Here's what the South China Morning Post had to say:
"The problem lies in the use of high-quality fly ash, a fine powder chemically identical to volcanic ash, collected from the chimneys of coal-fired power plants. When mixed with cement and gravel, it can give the tracks' concrete base a lifespan of 100 years.
According to a study by the First Survey and Design Institute of China Railways in 2008, coal-fired power plants on the mainland could produce enough high-quality fly ash for the construction of 100 kilometres of high-speed railway tracks a year.
But more than 1,500 kilometres of track have been laid annually for the past five years. This year 4,500 kilometres of track will be laid with the completion of the world's longest high-speed railway line, between Beijing and Shanghai. Fly ash required for that 1,318-kilometre line would be more than that produced by all the coal-fired power plants in the world...
...Professor Wang Lan , lead scientist at the Cement and New Building Materials Research Institute under the China Building Materials Academy, said that given poor quality control on the mainland, the use of low-quality fly ash, and other low-grade construction materials, was "almost inevitable" in high-speed railway construction."