Just saw on the BBC news that the building in Taiwan that collapsed had been "reinforced" with tin cans and styrofoam (polystyrene) in an attempt to save on costs. Even for the lax building methods of the far east and asia that is pretty extreme http://www.bbc.co.uk/news/world-asia-35515749
Makes you wonder about the safety of foreign hotels in the far east. Miracle it stayed up that long. I bet the builder has long gone by now as they have the death penalty over there.
The styrofoam is to form voids to lighten the structure and provide insulation. There is nothing at all wrong with the principle and ill informed headline grabbing comments in the media do our industry no good at all!! That is not to say that the work is done properly though looking at the picture there is nothing obviously wrong. The concrete looks to be pretty fresh to me so if I had to guess,I'd suggest that the wall may have been loaded before the concrete was properly cured. No concrete structure of any kind will accept overload before it has gained adequate strength, or try pushing a brick wall before the muck has gone off.
Poor quality work that, looks like tins you get milk or oil in. British Builder's would use top quality beer tins. That concrete looks very fine no gravel is that the norm abroad.