Blum's speedup theorem showing unclassifiable complexity languages? Do any of Blum's theorems prove that there exist decidable languages that are unclassifiable anywhere in the time hierarchy? In other words, asserting they (mentioned in the proofs) are computable within any time $O(f(n))$ for some time-constructable function $f(n)$ leads to a contradiction?
If a language is decidable then it is accepted by some Turing machine. The running time of that Turing machine is by definition time-constructible. So any computable function has a time-constructible upper bound by definition.