Stress transfer due to creep of concrete on composite bridges

U konverziji probne norme za mostove ENV-1994-2 u EN postavlja se pitanje točnijeg proračunavanja naponskog prelaganja od puzanja betona. Za manje raspone spregnutih mostova udio betona je relativno veći, pa je i utjecaj puzanja na nosač jači. U točnijoj analizi koeficijent puzanja φ treba korigirati s faktorima ΨA,L i ΨI,L. U radu se prikazuje geneza korekcijskih faktora Ψ, a na primjeru su pokazane razlike koje prema dopuštenoj aproksimaciji nisu uvijek na strani sigurnosti.The issue of a more accurate calculation of stress transfer induced by creep of concrete was raised during conversion of the European prestandard for bridges ENV-1994-2 into the European standard (EN). For smaller spans of composite bridges the proportion of concrete is relatively higher, so that the influence of creep on girder is also higher. In a more accurate analysis the coefficient of creep φ should be corrected using factors ΨA,L and ΨI,L. The genesis of creep multipliers Ψ is presented and the differences which, according to allowable approximation, are not always on the side of safety, are illustrated by an example