On the design and checking of reinforced and prestressed concrete compressed slender members, faced to creep. Simplified methods and spanish codes of practice

Abstract

Creep is a very important factor in concrete structures having compressed lsender members, although very simplified approaches are often used for designing and checking in normal methods and codes of practive. In this paper, an appropiate way to consider creep in these methods and also a simplification of simple suports design and check, for rapid calculations, are presented. The general problem of properly isolating a member from a frame, subsisting into the Spanish reinforced concrete code (EH-81), is revised and, for the same part of this code, comments on the basical formula for simple supports, that appears to be deeply improved nowadays without aby difficulty, are made. So applied research faced to this code topics is suggested to be undertaken or gone on. FInally, the big level difference, dealing with this matter, betwen both the EH-82 code and the Spanish prestressed concrete one (EP-80) is underlined. In conclusion, caution is always needed, and rigurous approaches if possible recommended, when making a priori simplifications in everything, basical research included, leading to these structures practice, where the highly nonlinear conjunction of a different effect set makes possible big errors in practical results.