On the redistribution of bending moments in two-span RC beams and slabs exposed to fire
Robert Kowalski , Marek Urbański
AbstractThis paper shows consideration of decrease in cross-section stiffness in commonly used in practice RC (reinforced concrete) beams and slabs in cases when only reinforcing bars or only concrete compressed zone, which is subjected to fire. Analyses were based on: (1) standard fire curve [EN 1991-1-2]; (2) 500 oC isotherm method assumptions [EN 1992-1-2]; (3) mechanical properties of reinforcing steel heated up to high temperature. Afterwards, based on estimated decrease of cross-sections stiffness, the redistribution of bending moments was calculated in some cases of two-span RC beams and slabs subjected to fire from their bottom face. Due to the bending moment redistribution, one could expect a reduction of bending moments in span cross-sections and an increase of support bending moment. As a result of this phenomenon, the ultimate limit state of the structural multi span elements might occur after shorter fire duration than it could be expected when redistribution of bending moments is neglected.
|Journal series||Journal of Civil Engineering and Architecture, ISSN 1934-7359|
|Publication size in sheets||0.75|
|Keywords in English||concrete, cross-section, fire design, stiffness|
|Score|| = 7.0, 22-12-2019, ArticleFromJournal|
= 7.0, 22-12-2019, ArticleFromJournal
|Publication indicators||= 3.0|
|Citation count*||3 (2020-09-06)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.