Assoc Prof Tan Kiang Hwee
Department of Civil Engineering
National University of Singapore
CE5510 Advanced Structural
Concrete Design
- Design & Detailing
of Openings
in RC Flexural Members-
DEPARTMENT OF CIVIL ENGINEERING


 Tan K H, NUS
A/P Tan K H, NUS A/P Tan K H, NUS 2
In this lecture
We will explore
!Types of openings
!Behaviour of beams with large
openings
!Design for ultimate strength
!Crack Control
!Deflection Calculation
DEPARTMENT OF CIVIL ENGINEERING


 Tan K H, NUS
A/P Tan K H, NUS A/P Tan K H, NUS 3
At the end of the lecture
You should be able to
!Understand the behaviour of beams
with openings under bending and
shear

! Tan, K.H. and Mansur, M.A., "Design Procedure for
Reinforced Concrete Beams with Web Openings",
ACI Structural Journal, Vol. 93, No. 4, USA, July-
August 1996, pp. 404-411.
! Mansur, M.A., Huang, L.M., Tan, K.H. and Lee, S.L.,
"Analysis and Design of R/C Beams with Large
Web Openings", Journal of the Institution of
Engineers, Singapore, Vol. 31, No. 4, July/August
1991, pp. 59-67.
Page 6
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University
of
Singapore
© Tan KH
NUS
Page 7
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University
of
Singapore
© Tan KH
NUS
Opening in beam
Page 8
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University
of
Singapore
© Tan KH

Page 11
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University
of
Singapore
© Tan KH
NUS
TS T2
Page 12
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University
of
Singapore
© Tan KH
NUS
Page 13
National
University
of
Singapore
© Tan KH
NUS
DESIGN TOOLS
" Finite element analysis:
• elastic stress state
• area of stress concentration
" Truss analysis (Strut-and-tie model):
• lower bound approach
• detailing for crack control and strength
" Tests:

M
t
+M
b
+ Nz = M
= M
N
t
+ N
b
= 0
V
t
+ V
b
= V
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National
University
of
Singapore
© Tan KH
NUS
Inadequately
reinforced
openings
Page 18
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University
of

of
Singapore
© Tan KH
NUS
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University
of
Singapore
© Tan KH
NUS
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National
University
of
Singapore
© Tan KH
NUS
Page 24
National
University
of
Singapore
© Tan KH
NUS
Shear
carried by
chords
Page 25
National