> Any building using concrete for a structure should be aiming to last at least 100 years. I don't know which country you have in mind but in Europe the constr

> Any building using concrete for a structure should be aiming to last at least 100 years. I don't know which country you have in mind but in Europe the construction industry by law is obligated to design concrete structures for residential buildings that ensures a useful life of at least 50 years, and by definition that means that the building structure shall not require maintenance for at least 50 years. Moreover, concrete as a widespread structural material is relatively new, and city centers are still packed with contrete buildings that were built when the technology started popping up. In fact, in general a building with concrete structure is only demolished when it's not possible to retrofit or renovate it effectively, due to unrelated reasons such as increasing occupation density that would not be cost-effective by reinforcing the concrete structure. My point is that concrete structures are not demolished with enough frequency to be of any concern. The main reason is that concrete structures are simply too expensive to be demolished, moreso in urban centers. Thus your concern simply isn't relevant in the real world because economics already impose the same restrictions that are expressed in your environmental concerns.