High-strength concrete | An-Najah Staff

A Numerical Approach for Modeling the Fire Induced Restraint Effects in Reinforced Concrete Beams

Sun, 2014-06-01 10:46 — Monther Dwaikat

Journal Title, Volume, Page:

Fire Safety Journal Volume 43, Issue 4, Pages 291–307

Year of Publication:

2008

Link:

http://www.sciencedirect.com/science/article/pii/S0379711207000938

Authors:

M.B. Dwaikat

Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824-1126, USA

Current Affiliation:

Building Engineering Department, Faculty of Engineering and Information Technology, An-Najah National University, Nablus, Palestine

[email protected]

V.K.R. Kodur

Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824-1126, USA

Preferred Abstract (Original):

In this paper, a model to predict the influence of fire induced restraints on the fire resistance of reinforced concrete (RC) beams is presented. The three stages, associated with the fire growth, thermal and structural analysis, for the calculation of fire resistance of the RC beams are explained. A simplified approach to account for spalling under fire conditions is incorporated into the model. The validity of the numerical model is established by comparing the predictions from the computer program with results from full-scale fire resistance tests. The program is used to conduct two case studies to investigate the influence of both the rotational and the axial restraint on the fire response of the RC beams. Through these case studies, it is shown that the restraint, both rotational and axial, has significant influence on the fire resistance of the RC beams.

Response of Restrained Concrete Beams under Design Fire Exposure

Sun, 2014-06-01 09:25 — Monther Dwaikat

Journal Title, Volume, Page:

ASCE Journal of Structural Engineering, Vol. 135, No. 11, pp. 1408-1417

Year of Publication:

2009

Link:

http://ascelibrary.org/doi/abs/10.1061/(ASCE)ST.1943-541X.0000058

Authors:

M. B. Dwaikat

Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Michigan State Univ., MI 48824

Current Affiliation:

Building Engineering Department, Faculty of Engineering and Information Technology, An-Najah National University, Nablus, Palestine

[email protected]

V. K. R. Kodur

Professor, Dept. of Civil and Environmental Engineering, Michigan State Univ., MI 48824

Preferred Abstract (Original):

Results from fire resistance experiments on six RC beams are presented in this paper. The test variables included concrete strength (permeability), support conditions, fire scenario, and load ratio. Data from fire tests are used to illustrate the comparative performance of high strength concrete (HSC) and normal strength concrete (NSC) beams under fire conditions. Also, data from the tests is used to validate a macroscopic finite-element model specifically developed for tracing the fire response of RC beams. Results from the tests and numerical studies show that HSC beams have lower fire resistance than that of NSC beams. It is also shown that HSC beams exhibit higher levels of spalling which is largely influenced by the permeability of concrete, type of fire exposure, load level, and restraint conditions. Similarly, the type of fire scenario, axial restraint, and load level have significant influence on the overall fire resistance of RC beams. These factors are to be considered for evaluating the fire resistance of RC beams under fire conditions.