Deformation Characteristics of Fire Damaged and Rehabilitated Normal Strength Concrete Beams
In recent years, fire accidents have been steadily
increased and the amount of property damage caused by the accidents
has gradually raised. Damaging building structure, fire incidents bring
about not only such property damage but also strength degradation and
member deformation. As a result, the building structure undermines its
structural ability. Examining the degradation and the deformation is
very important because reusing the building is more economical than
reconstruction. Therefore, engineers need to investigate the strength
degradation and member deformation well, and make sure that they
apply right rehabilitation methods. This study aims at evaluating
deformation characteristics of fire damaged and rehabilitated normal
strength concrete beams through both experiments and finite element
analyses. For the experiments, control beams, fire damaged beams and
rehabilitated beams are tested to examine deformation characteristics.
Ten test beam specimens with compressive strength of 21MPa are
fabricated and main test variables are selected as cover thickness of
40mm and 50mm and fire exposure time of 1 hour or 2 hours. After
heating, fire damaged beams are air-recurred for 2 months and
rehabilitated beams are repaired with polymeric cement mortar after
being removed the fire damaged concrete cover. All beam specimens
are tested under four points loading. FE analyses are executed to
investigate the effects of main parameters applied to experimental
study. Test results show that both maximum load and stiffness of the
rehabilitated beams are higher than those of the fire damaged beams.
In addition, predicted structural behaviors from the analyses also show
good rehabilitation effect and the predicted load-deflection curves are
similar to the experimental results. For the further, the proposed
analytical method can be used to predict deformation characteristics of
fire damaged and rehabilitated concrete beams without suffering from
time and cost consuming of experimental process.
 S. J. Lee, “A Study on Structural Behaviors of Fire-Damaged Reinforced
Concrete Beams with Normal Strength Concrete,” M.S. thesis, Ewha
womans university, Seoul, 2003.
 M. K. Shin, “Structural behaviors of fire-damaged reinforced concrete
beams with high strength,” M.S. thesis, Ewha womans university, 2004.
 E. G. Choi, Y. S. Shin and H. S. Kim, “Structural damage evaluation of
reinforced concrete beams exposed to high temperatures,” Journal of Fire
Protection Engineering, vol. 23, no. 2, pp 135-151, Apr. 2013.
 J. H. Ahn, “Structural behaviors of Fire-damaged normal strength
concrete beams retrofitted with Polymer mortar,” M.S. thesis, Ewha
womans university, Seoul, 2003.
 J. Y. Kang, H. W. Jung and Y. S. Shin, “An Parametric study on structural
behaviors of Fire-damaged concrete beams retrofitted with Polymer
mortar,” in Proceeding of Architectural Institute of Korea, Seoul, Korea,
Oct. 2005, pp. 227-230.
 C. S. Poon, S. Azhar, M. Anson, and Y. L. Wong, “Strength and
durability recovery of Fire-damaged concrete after post-fire-curing,”
Cement and Concrete Research, vol. 31, pp. 1307-1318, Sep. 2001.
 J. W. Lee, K. H. Choi, and K. P. Hong, “Strength recovery of
Fire-damaged concrete after Post-fire-curing,” in Proceeding of Korea
Concrete institute, Muju, Korea, Mar. 2006, pp. 170-173.
 R. H. Haddad, N. AL-Mekhlafy, and A. M. Ashteyat, “Repair of
Heat-damaged reinforced concrete slabs using Fibrous composite
materials,” Construction and Building Materials, vol. 25, pp. 1213-1221,
 T. Z. Harmathy, Properties of building materials at elevated temperatures,
DRP Paper No. 1080 of the Division of Building Research, Ottawa:
National Research Council of Canada, 1983.
 T. Z. Harmathy, Properties of building materials, Bethesda, MD: Society
of Fire Protection Engineers and National Fire Protection Association,
1988, pp. 378-391.
 ACI Committed 216, Guide for determining the fire endurance of
concrete elements, American Concrete Institute Committee Report, ACI
216R1-48, Farmington Hills, MI, USA 1994
 Eurocode 2, Design of concrete structures-part 1-2: general
rules-structural fire design, ENV 1992-1-2, European Committee for
 RM. Haj-Ali, J. Choi, and H. S. Kim, “Integrated fire dynamics and
thermomechanical modeling framework for steel-concrete composite
structures,” Steel and Composite Structure, vol. 10, pp. 129-149, Oct.
 J. Choi, RM. Haj-Ali, and H. S. Kim, “Integrated fire dynamic and
thermomechanical modeling of a bridge under fire,” Structural
Engineering and Mechanics, vol. 42, no. 5, pp 815-829, May. 2012.