Since other members wrote, that my my original question here Shuttle silica ceramics black tiles? was too broad I modified it to asked just one thing, while the other questions I will asked later.
Shuttle silica ceramics black tiles, were mostly air and so fragile that you can break, crush them with the force of your hands (quote from NASA documentary). They were usually damaged by ice in upper atmosphere during ascend and from some old quora post potentially by micrometeoroids, space debris in space and heat during reentry. In 1996 they were introduced new stronger black tiles https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120016878.pdf but because problems with their weight and heat conductivity they were used only on some parts of the Orbiter. These new tiles could survive ascend ice impact without any damage (there is picture in link above page 11, how they look after 3 flights vs old tiles) but someone here at Space Stack-Exchange wrote that non of Shuttle tiles survive more than 10 flights. Also from NASA documentary, during reentry Shuttle must survive not only lot of reentry heating, but also lot of aerodynamics pressure.
My question :
If those early silica ceramics black tiles were so fragile how can they survive AD pressure during reentry? Did shockwave protect them from direct impact?