I would like to everyone for your comments. I really appreciate your dedication on my thread. First, ctmtwilliams, the code specifications for concrete in my country comes since 1987, so you can imagine how delayed we are, but that's not an impediment. I actually use de ACI 318-99 code, and I am allowde to do it. About the requiremnts, it's true that a hospital has many details to take them in mind, well, now we began the project I am introduced completely in the scope of the project. Now, pba, thank you very much for your advises. I'd like to give you (to all) a brief descriptions of the project. Weel the building will be divided in two separated blocks, and one is bigger than the other. About the special requiremnts my company suplied me with the actual equipment that will be in use. It's true, they must to be cosidered carefuly. But some details are not well defined, for example, the necesary space for elevator's machine are not well visualized, specially for the architects (they are two). Now they have to make a lot of corrections, and I am just waiting.