Am 26.04.2019 um 08:42 schrieb Recliner:
It was reported a couple of weeks ago that they'd used "the wrong type
of concrete" for some of the construction, and implied they were having
to chip that out and replace it.

Ah, I hadn't seen that, perhaps because I was away. It does sound like a
beginner's mistake, hardly to be expected in a flagship project like that.

Oh, in Germany, "we" made that mistake with the concrete sleepers for
several lines renovated to high-speed standard in the 1990's; they were
happy to renovate Halle-Berlin a second time some 10 years later.