high strength concrete | An-Najah Staff

A Numerical Model for Predicting the Fire Resistance of Reinforced Concrete Beams

Sun, 2014-06-01 12:41 — Monther Dwaikat

Journal Title, Volume, Page:

Cement and Concrete Composites Volume 30, Issue 5, Pages 431–443

Year of Publication:

2008

Link:

http://www.sciencedirect.com/science/article/pii/S095894650700145X

Authors:

M. Dwaikat

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

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, United States

Preferred Abstract (Original):

A numerical model, in the form of a computer program, for tracing the behavior of reinforced concrete (RC) beams exposed to fire is presented. The three stages associated with the numerical procedure for evaluating fire resistance of RC beams; namely, fire temperature calculation, thermal analysis and strength analysis, are explained. A simplified approach to account for spalling under fire conditions is incorporated into the model. The use of the computer program for tracing the response of RC beams from the initial pre-loading stage to collapse stage, due to the combined effect of fire and loading, is demonstrated. The validity of the numerical model is established by comparing the predictions from the computer program with results from full-scale fire resistance tests. Through the results of numerical study, it is shown that the type of failure criterion has significant influence on predicting the fire resistance of RC beams.

Performance-Based Fire Safety Design of Reinforced Concrete Beams

Sun, 2014-06-01 12:37 — Monther Dwaikat

Journal Title, Volume, Page:

Journal of Fire Protection Engineering, Vol. 17, No. 3, pp. 293-320

Year of Publication:

2007

Link:

http://jfe.sagepub.com/content/17/4/293.abstract

Authors:

M. Dwaikat

Department of 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

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

Preferred Abstract (Original):

A numerical model, in the form of a computer program, is presented for tracing the fire behavior of reinforced concrete (RC) beams over the entire range of loading from pre-fire conditions to collapse under fire. The three stages associated with the analysis of fire resistance; namely, establishing the fire temperature—time development, calculating the heat transfer through the structure from the fire, and the structural analysis are explained. The model, which accounts for nonlinear material properties at elevated temperatures, is capable of predicting the fire resistance of RC beams under realistic fire scenarios, load levels, and failure criteria. The validity of the numerical model is established by comparing the predictions from the computer program with results from full-scale fire resistance tests. Through the results of numerical study, it is shown that the type of failure criterion, load level, and fire scenario have significant influence on fire resistance of RC beams. The computer program can be used to undertake performance-based fire safety design of RC beams for any value of the significant parameters, such as fire exposure, concrete cover thickness, section dimensions, concrete strength, concrete type, and load intensity.

Fire Induced Spalling in High Strength Concrete Beams

Sun, 2014-06-01 08:44 — Monther Dwaikat

Journal Title, Volume, Page:

Fire Technology, Volume 46, Issue 1, pp 251-274

Year of Publication:

2010

Link:

http://link.springer.com/article/10.1007%2Fs10694-009-0088-6

Authors:

M. B. Dwaikat

Department of CEE, Michigan State University, East Lansing, MI, USA

Current Affiliation:

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

[email protected]

V. K. R. Kodur

Department of CEE, Michigan State University, East Lansing, MI, USA

Preferred Abstract (Original):

A macroscopic finite element model is extended to account for fire induced spalling in high strength concrete (HSC) beams. The model is based on the principles of mechanics and thermodynamics and utilizes pore pressure calculations to predict fire induced spalling in concrete. For validating the model, spalling measurements were made by conducting fire resistance experiments on four normal strength and high strength concrete beams. Spalling predictions from the model are compared with the measured values of spalling at various stages of fire exposure. The validated model is applied to investigate the influence of fire scenario, concrete strength (permeability) and axial restraint on the fire induced spalling and fire response of RC beams. Results from the analysis show that fire scenario, and concrete permeability largely influence the extent of fire induced spalling in concrete beams. Further, it is also shown that the extent of spalling has significant influence on the fire resistance of RC beams.