Post on 13-Apr-2020
IS-BETON
Jörg Jungwirth Poster n° 339
Structural Behavior of Tension Members in Ultra High Performance ConcreteImprovements in the concrete mix design, along with the addition of metallic fibers, have lead to a new high performance cement material known as Ultra High Performance Concrete. A Compression resistance about 150 - 250 MPa and a reliable tension resistance can be achieved.The high performance concrete project currently under way at the Structural Concrete Laboratory (IS-BETON) aims at examining new concept and design approaches to design statically efficient and economically viable structures using UHPC. In this scope a study on the tensile behavior of UHPC has been conducted. Material tests and tests on structural members with reinforcement bars have been performed. A schematic representation of the material behavior allows a general description of the behavior of structural members in tension.
0
2
4
6
8
10
0 1 2 3 4ε [‰]
σ [N
/mm
2 ]
specimen 3without fibers
specimen 2
specimen 1
0
2
4
6
8
10
12
0.0 0.5 1.0 1.5 2.0∆ l [mm]
σ [N
/mm
2 ]
u [mm]0.0 1.51.00.5
specimen 5
specimen 6
specimen 4
0
2
4
6
8
10
12
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
ε [ ‰ ]
σ [N
/mm
2 ]
u [mm]0.0 1.51.00.5
f ct.matrix l
Phase 1
l ∆l
s r
Phase 2
1
3
2
E matrix
u
( , , , )ct f f f ff f lρ τ=> ∅
l
u
Phase 3
E *
*l u lEσ
∆ = +
Material Behavior
Dis
tribu
ted
Def
orm
atio
nC
rack
O
peni
ng
Tens
ile b
ehav
ior o
f an
UH
PC
ele
men
t
Testing of Tension Members
-
4.1%
2.5%
1.0%-
[%]ρ
10626004∅15.2FpT5
69812564∅20Fs >> FcT4
4478044∅16Fs > FcT32514524∅12Fs ≈ FcT2
---Fs = 0T1[kN][mm2][mm2]FsAsChosenCriterion
Tension Behavior
Test
Set
upfo
r ten
sion
test
s on
st
ruct
ural
mem
bers Te
stPa
ram
eter
sC
rack
ing
Beha
vior
Ope
ned
Cro
ss S
ectio
n
48.035.525.918.6
-[MPa]
ft
6.728.48.69
[MPa]fct=ft – Fs/A
38.511.210.910.5
7.8(?)[MPa]fCrack
12.510624∅15.2T512.5606984∅20T412.5504474∅16T312.5402514∅12T212.5--T1[mm][mm][kN][mm2]
sCrack,finesCrackFsReinforcement
Directeur de thèseProf. A. Muttoni
LiteratureJungwirth J., Muttoni A., Structural Behavior of
Tension Members in UHPC, EPFL-IS-BETON, Lausanne, 2004
Jungwirth J., Muttoni A., Versuche an Bauteilen aus ultrahochfesten Beton – Teil 1 Material, EPFL-IS-BETON, Lausanne, 2004
Jungwirth J., Muttoni A., Versuche an Bauteilen aus ultrahochfesten Beton – Teil 2 Bauteile, EPFL-IS-BETON, Lausanne, 2004
Plumey S., Jungwirth J., Muttoni A., Comportement des éléments en béton à ultra hautes performances, EPFL-IS-BETON, Lausanne, 2002
http://is-beton.epfl.ch/Person/Jungwirt/
Res
ults
of t
he te
nsio
n te
sts
on
stru
ctur
al m
embe
rs
Mod
el fo
r ten
sion
test
s on
stru
ctur
al
mem
bers
Sponsored by:
0
20
40
0 5 10strain (l 0 =1m) [‰]
nom
inel
stre
ss N
/Ato
t [M
Pa]
ρ = 1%4∅12
reinforcement4∅20
ρ = 0%
reinforcement4∅12
reinforcement4∅16
ρ = 2.5%4∅16
ρ = 4.1%4∅20
T1
T2
T3
T4
f Crack
f t
f ct
0
25
50
0 5 10strain (l 0 =1m) [‰]
nom
inel
stre
ss N
/Ato
t [M
Pa]
4Τ15S1770σPo = 0.7ftk
ρ = 2.5%4∅16
T3
T5
0
5
10
15
20
25
30
0 2 4 6 8 10strain (l 0 =1m) [mm/m]
nom
inal
stre
ss N
/Ato
t [M
Pa]
ρ = 0%calculated (see material behavior)
steel4∅16
calculatedρ = 2.5%
testingρ = 2.5%
behavior of ordinary reinforced concrete with ρ = 2.5%
T3
Measured characteristic values:fct,Matrix = 8.9 MPafct = 9.7 MPaE = 60 GPa