Every structural designer's design can be considered alright based on his standards. It's the natural passage of time that will tell how strong it is and obviously the natural or manmade events that will happen within its serviceability. Serious considerations to all factors plus "COMMON...
Progressive collapse is likely to happen to a structure which is designed conventionally. If you wanted to have a structure to stand this kind of assumption, you have to remove all external collumns before the design phase begins, thereby creating a strong internal collumns as a factor of...
The maximum spacing of rebars is not much of a factor here, but the effect on minimum spacing on the shorter side. The toleraces due to aggregate size, minimum concrete cover, min req'd spacing in relation to your rebar size, min required steel area per cross sectional area of concrete must be...
