View
240
Download
9
Category
Preview:
Citation preview
Centre forCement and Concrete
““SHEARBAND:SHEARBAND:Verification of a Novel Punching Shear Reinforcement System for Flat Slabs”
Kypros PilakoutasKypros Pilakoutas --ChristianaChristiana Ioannou (speaker)Ioannou (speaker)CentreCentre for Cement and Concretefor Cement and Concrete-- The University of SheffieldThe University of Sheffield
http://www.shef.ac.uk/~ccc/
Centre forCement and Concrete
ProblemProblemSolutionsSolutionsShearbandShearband reinforcementreinforcementExperimentsExperimentsResultsResultsConclusionsConclusions
OutlineOutline
Centre forCement and Concrete
Anchorage:Anchorage: The problem with The problem with Punching Shear ReinforcementPunching Shear Reinforcement
Shear headsShear heads
StudStud--railrail
ShearbandShearband
Conventional Conventional Reinforcement Reinforcement
Centre forCement and Concrete
ΤΤhe he shearband shearband on on top of the upper top of the upper flexural flexural reinforcementreinforcement
50 50
planplan
Thickness=0.8mm
ShearbandShearband
100 100
13525.4 mm
Centre forCement and Concrete
1) maximum effective depth
2) easy placement
3) bond
4) design based on Codes
Advantages
Centre forCement and Concrete
TestsTests
Control Slab (PSSA)Control Slab (PSSA)
7 Slabs (PSSB7 Slabs (PSSB--PSSG) PSSG)
Slab with holes (PSSHSlab with holes (PSSH))
Further work on slabs with holesFurther work on slabs with holes
Centre forCement and Concrete
SS1 SS2SS3
SS4
SS5
SS6
SS7
SS8
Distribution of Distribution of ShearbandShearband
SS1 SS2
SS3SS4
SS5
SS6
SS7
SS8
SS1 SS6
SS7
SS12
SS1 SS6
SS7 SS12
SS1 SS6
SS7 SS12SS9 SS10
PSSB,C
PSSF PSSG
PSSEPSSD
Centre forCement and Concrete
Slab PSSHSlab PSSH SS1 SS6
SS7 SS12
Centre forCement and Concrete
PSSB
PSSD PSSE
PSSC
Centre forCement and Concrete
PSSF
PSSH
PSSG
Centre forCement and Concrete
Control SlabControl Slab
PSSAPSSA
Centre forCement and Concrete
PSSCPSSC
Centre forCement and Concrete
ResultsResultsSlab fc (MPa) Failure Load
(kN)
Maximum Deflection
(mm)
PSSA 32.3 454 11.45
PSSB 39 560 25.35
PSSC 41.2 560 24.11
PSSD 42.2 560 21.39
PSSE 43.4 573 26.27
PSSF 43.4 598 30.19
PSSG 38.0 590 27.78
PSSH 38.0 544 17.44
Centre forCement and Concrete
LoadLoad--DeflectionDeflectionL
oad
(kN
)
0
100
200
300
400
500
600
5 1010 15 20 25 30
PSSEPSSBPSSA
Deflection (mm)
D850
Centre forCement and Concrete
LoadLoad--Deflection Deflection
Deflection (mm)
Load
(kN
)
0
100
200
300
400
500
600
5 10 15 20 25 30 35 40
PSSH@D600PSSH@D850PSSG@D600 PSSG@D850
D600
D850
Centre forCement and Concrete
LoadLoad--Strain in Flexural Strain in Flexural ReinforcementReinforcement
Lo a
d (k
N)
Strain (microstrain)
0
100
200
300
400
500
600
2000 4000 6000 8000 10000 12000 14000 16000 18000 20000
PSSAPSSBPSSCPSSD
S1S1
Centre forCement and Concrete
LoadLoad--Strain in Strain in ShearbandShearband
Strain (microstrain)
Loa
d (k
N)
0
100
200
300
400
500
600
500 1000 1500 2000 2500 3000 3500
SS4SS10
Slab PSSE
S4S4
S10S10
Centre forCement and Concrete
ConclusionsConclusions
The Shearband:Prevents brittle punching shear failure and leads to ductile behaviourFast and easy fixing; placed on top of main reinforcementAnchors over the top layer of main reinforcementMeets the criteria of International Codes of Practice
Centre forCement and Concrete
Future WorkFuture Work
Recommended