1. COST Action TU 0904
“St. CIRIL and METHODIUS” UNIVERSITY
FACULTY OF CIVIL ENGINEERING
SKOPJE - MACEDONIA
Cvetkovska Meri
Lazarov Ljupco
Todorov Koce
examination, assessment and repair of fire damaged rc structure of „refinery-okta“ in skopje

2. VIEW OF THE FIRED STRUCTURE
COST Action TU 0904
VIEW OF THE FIRED STRUCTURE
Model of structure in SAP2000

3. Schematic presentation of the fired structure
COST Action TU 0904
R1(G1- 55*100cm)
B3 (30*60cm) R1
9 m B3
B2 (45*60cm)
6 m
B1-less fire exposed beam
Schematic presentation of the fired structure

4. 1. VISUAL INSPECTION OF STRUCTURE
COST Action TU 0904
1. VISUAL INSPECTION OF STRUCTURE
Red color indicate temperaures round 6000C
Flexy color indicate temperaures round 9000C
Deformation of crane beam because of the restrained dilatation

5. 2. Experimental determination of the residual concrete strength
COST Action TU 0904
2. Experimental determination of the residual concrete strength
Before testing all the specimens were divided in two slices. The deteriorated (burned) slices had small height (3-6 cm) and rough surface
The speciment were taken without the destruction of reinforcement and were tested at the Testing laboratory of the Faculty of Civil Engineering in Skopje

6. COST Action TU 0904
TESTING EQUIPEMENT
Results of strength tests on samples that were not exposed to fire
Average strength of concrete exposed to fire was 9,24 MPa

7. Numerical determination of the residual concrete strength
COST Action TU 904
Numerical determination of the residual concrete strength
el.3
el.4
el.1
el.2 b)
22.5cm
axis of symmetry
22.5cm
428
628
222
228 a)
axis of symmetry
Isotherms in the cross section of the beam B2 (t=1.5hours),
residual concrete strength after cooling phase

8. Numerical determination of the residual concrete strength
COST Action TU 904
Numerical determination of the residual concrete strength
17.5cm
432
425 a)
axis of symmetry
el.3
el.4
el.1
el.2 b)
Isotherms in the cross section of the beam G2 (t=1.5hours),
b) residual concrete strength after cooling phase

9. Nonlinear thermal analysis
COST Action TU 904
Nonlinear thermal analysis
Time dependent temperatures of the reinforcing bars
Beam B2 which is exposed to fire from three sides
Beam G2 which is exposed to fire from three sides

10. Nonlinear stress-strain analysis
COST Action TU 904
Nonlinear stress-strain analysis
Time dependent stresses of reinforcement no.3 of beam B2, for cross section at mid span -1
-0,5
0,5 1
-6,5 -5
-3,5 -2
el.2(at the support)-heating phase
el.2(at the support)-cooling phase
el.2(at the mid span)-heating phase
el.2(at the mid span)-cooling phase
, as % of fy (T)
t=0= + 8Mpa
t=0=-14Mpa
t= e
*1000

11. Nonlinear stress-strain analysis
COST Action TU 904
Nonlinear stress-strain analysis
-0,2
0,2
0,6 1
-0,5
0,5
1,5 2
2,5
el.3-heating phase
el.3-cooling phase
-0,6 e
*1000
, as % of fy (T)
t=0= -4Mpa
t==-217Mpa
Time dependent stresses of reinforcement no.3
of beam B2, for cross section at mid span

12. Suggested repair of fire damaged structural elements
COST Action TU 904
Suggested repair of fire damaged structural elements
572.5
27.5
100 cm G1
60 cm
existing reinforcement
428 + 220 (additional reinforcement)
concrete cover to be eliminated
up to the existing stirrups
beam B2
Repair details of beam B2

13. Suggested repair of fire damaged structural elements
COST Action TU 904
Suggested repair of fire damaged structural elements

14. Suggested repair of fire damaged structural elements
COST Action TU 904
Suggested repair of fire damaged structural elements

15. Thank you for the atTention