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Edited byStefanus A. Kristiawan, Erik Schlangen, Henk Jonkers
Resilience and Reliabilityof Civil Engineering Infrastructures
TRANS TECH PUBLICATIONS
Stefanus A. K
ristiawan,
Erik Schlangen, Henk Jonkers
Resilience and R
eliability of C
ivil Engineering Infrastructures
ISBN: 978-3-03835-606-6Applied Mechanics and Materials Vol. 845Electronically available at http://www.scientifi c.net
AMM_Cover.indd 1 4/28/2016 3:22:25 PM
Applied Mechanics and MaterialsISSN: 1660-9336, ISSN/ISO: Applied Mechanics and Materials
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Table of Contents
Preface v
Scientific Committee, Sponsors vi
Chapter 1: Engineering Hydrogeology and Water Resources
Identification of Suspended Sediment Concentration in Stream Network
Y. Saadi, A. Suroso and I.B.G. Putra ............................................................................................... 3
Rainfall Simulation at Bah Bolon Watershed with Backpropagation Artificial
Neural Network Based on Rainfall Data Using Scilab
Setiono, R. Hadiani, E. Erlangga and Solichin .............................................................................. 10
Decentralized System of Greywater Recycling for Sustainable Urban Water Source
(Case Study: Surakarta City-Indonesia)
S. Qomariyah ................................................................................................................................. 18
Rainfall-Discharge Simulation in Bah Bolon Catchment Area by Mock Method,
NRECA Method, and GR2M Method
H. Rintis, Suyanto and Y.P. Setyoasri ........................................................................................... 24
The Analysis of Sediment Transport Using Yang Method, Engelund-Hansen
Method, and Bagnold Method in Bah Bolon River, Simalungun Regency of North
Sumatera
Suyanto, H. Rintis and M.S.P. Rian ............................................................................................... 30
Chapter 2: Geotechnical Engineering
Seismic Upgrade of Earth Dams - Australian Practice
H. Jitno ........................................................................................................................................... 37
Analysis of Seismic Ground Response in Makassar Using Geotechnical In Situ Tests
A. Arsyad, A.B. Muhiddin, R. Rante, A.R. Djamaluddin and A. Suprapti ................................... 52
A Numerical Method of the Flexible Pavement Supported by SSC on Expansive Soil
A.S. Muntohar ................................................................................................................................ 62
Axial Pile Capacity Prediction Obtained from Environmental Friendly Jack-In
Piling Test on Clayey Soil
Y. Muslih Purwana, N. Silmi Surjandari and H. Wahyu ............................................................... 70
Technical Review of Slope Failure (Case Study of Tawangmangu-Cemorosewu Sta.
4+600 Section)
A. Mustakim, Y. Muslih Purwana, A. Setyawan and M. Suprapto ............................................... 76
Finite Element Method (FEM) of Rigid Pavement Laid on Soft Soil Stabilized with
Soil Cement Column
F. Hary Yanto, Y. Muslih Purwana and N. Silmi Surjandari ........................................................ 83
Stress Analysis in the Combination of Footplate and Caisson Foundation
N. Silmi Surjandari, Y. Muslih Purwana and R. Erlyana Majid .................................................... 89
Development of Graphical Method of Pile Group Foundation Design
N. Djarwanti, R. Harya Dananjaya and F. Prasetyaningrum ......................................................... 94
Resilience and Reliability of Civil Engineering Infrastructures
x
Pencel Pressuremeter Efficiency for Data Compilation and Analysis
F. Messaoud and P.J. Cosentino .................................................................................................. 100
A Quick Assessment Method for the Mud Eruption Hazard Risks of the Lusi
Surrounding Area with a Special Reference to Ground Deformation Behavior
D.S. Agustawijaya........................................................................................................................ 106
Chapter 3: Materials and Structures in Construction
Inclusion-to-Specimen Volume Ratio Influence on the Strength and Stiffness
Behaviors of Concrete: An Experimental Study
A. Han, B.S. Gan, R. Yuniarto, A. Yesica and R.N. Editia ......................................................... 113
Yield Penetration Displacement of Lightly Reinforced Concrete Columns
A. Wibowo, J. Wilson, N. Lam and E. Gad ................................................................................. 119
Performance of Reactive Powder Concrete Partial Prestressed Beam-Column
Sub-Assemblage Structure System with Partial Prestressed Ratio Exceeds 30%
S.A. Nurjannah, B. Budiono, I. Imran and S. Sugiri.................................................................... 126
Experimental Study on Flexural Behavior of Reinforced Concrete Beams with
Variety Lap Splices of Reinforcing Steel Bars
M. Teguh and N. Mahlisani ......................................................................................................... 132
Determination of Damage Location in Reinforced Concrete Beams Using Mode
Shape Curvature Square (MSCS) Method
F. Saleh......................................................................................................................................... 140
Experimental Investigation of Trapezoidal Profile Sheeting under Varying Shear
Spans
A. Siva, S. Swaminathan, K. Prasanth and R. Senthil ................................................................. 148
Experimental Study on Shear Capacity of RC Beams Strengthened with Carbon
Fiber Reinforced Polymer Mandated by ACli 440
S. Tudjono, H. Indarto and M. Devi ............................................................................................ 154
Structural Behavior of Steel Reinforced Sandwich Concrete Beam with Pumice
Lightweight Concrete Core
Akmaluddin, S. Murtiadi and Z. Gazalba .................................................................................... 158
Behaviors of Repaired Edge Column Slab Connections after Punching Failure
Using Normal and Non-Shrinkable (CAH) Concrete
I.K. Sudarsana .............................................................................................................................. 166
Experimental Investigation on the Flexural Performance of Brick Masonry Wall
Retrofitted Using PP-Band Meshes under Cyclic Loading
A. Triwiyono, F. Neo, J. Ardianto, G. Maylda Pratama and A. Sugijopranoto ........................... 175
Strengthening and Retrofitting Strategy for Masonry (New Build Construction in
Indonesia)
G.A. Susila, P. Mandal and T. Swailes ........................................................................................ 181
The Effect of Steel Ring Width Variations as the External Confinement on
Load-Moment Interaction Behavior of Reinforced Concrete Column
E. Safitri, I. Imran, Nuroji and S. Asa'ad ..................................................................................... 188
Strength Models of Axial Capacity of FRP-Confined Circular Concrete Columns
I.B.R. Widiarsa and I.N. Sutarja .................................................................................................. 193
xi
Applied Mechanics and Materials Vol. 845
Sisal Fiber as Steel Bar Replacement of Lightweight Concrete under Flexural
Loading
S. Murtiadi and Akmaluddin ........................................................................................................ 202
Flexural Capacity of Bamboo Strip Notched Reinforced Concrete Beams
A. Setiya Budi, E. Rismunarsi and Sunaryo ................................................................................ 208
Performance of Ferro Foam Concrete Girder Beam Subjected to Static Load
M. Afifuddin and Abdullah .......................................................................................................... 214
Steel Fiber Reinforced Concrete to Improve the Characteristics of Fire-Resistant
Concrete
Y. Nurchasanah, M.A. Masoud and M. Solikin ........................................................................... 220
An Artificial Neural Networks Model for Compressive Strength of Self-Compacting
Concrete
A. Suryadi, Qomariah and M. Sarosa .......................................................................................... 226
Chapter 4: Dynamic of Structures and Earthquake Resistance of
Buildings
Friction-Type Seismic Isolation Device of Steel Pile Foundation in Shaking Table
Tests and its Numerical Simulations
B.S. Gan, S. Nakamura, N. Sento and K. Ito ............................................................................... 233
Effect of Supplemental Damping on the Seismic Performance of Triple Pendulum
Bearing Isolators under Near-Fault Ground Motions
S. Rezaei and G.G. Amiri ............................................................................................................ 240
Structural Assessment: A Case Study of Low Rise Building Performance after
Experiencing Earthquake
Widodo, Mayhendra and Sarwidi ................................................................................................ 246
Seismic Vulnerability of Reinforced Concrete Building Based on the Development of
Fragility Curve: A Case Study
E. Wijayanti, S. Adi Kristiawan, E. Purwanto and S. Sangadji ................................................... 252
Parametric Study on the Influence of Bays Number and Frame-Span Length on the
Redundancy Indices of Reinforced Concrete Structures
M.P. Cripstyani, S.A. Kristiawan and E. Purwanto ..................................................................... 259
Structural Performance Evaluation with Pushover Analysis Case Study:
The Integrated Central Surgery Building, Bethesda Hospital in Yogyakarta
E. Purwanto, A. Supriyadi and Masbudi ...................................................................................... 265
Structural Response and Pounding of Andalas University Hospital Building Using
New Indonesian Seismic Code SNI 1726-2012
Fauzan, F. Anas Ismail and Z. Al Jauhari .................................................................................... 274
Retrofitting of STKIP ADZKIA Padang Building Using V-Inverted Steel Bracing
Fauzan, F. Anas Ismail, A. Hakam, Zaidir, N. Yanto and S. Apriwelni ...................................... 283
Chapter 5: Monitoring, Maintenance and Management in Construction
Design of Structural Health Monitoring Using Wireless Sensor Network Case Study
Pasupati Bridge
A.D. Kumalasari and S. Tjondronegoro ...................................................................................... 293
Resilience and Reliability of Civil Engineering Infrastructures
xii
Optimization in Indonesia’s Bridge Preventive Maintenance Programme:
A Proposal
H.A. Yuniarto and Y. Qaradhawi ................................................................................................ 299
Relationship between Predetermined Maintenance Interval and Maintenance
Performance
C.P. Au-Yong, A. Shah Ali and F. Ahmad .................................................................................. 305
A Study on the Characteristics of Building Maintenance on Public Universities in
Malang City
A.M. Hajji and A. Suharsono ....................................................................................................... 311
Application of AHP Method for Determining the Priority of Puskesmas Pembantu
Building Maintenance Based on GIS in Sukoharjo District Central of Java
W. Hartono, M. Mufti Abadi, Sugiyarto, S. Marwoto and B. Laksito ........................................ 318
Implementation of Life Cycle Costing: A Case of Hostel Building in Kediri, Eastern
Jawa, Indonesia
P.F. Kaming and J. Marliansyah .................................................................................................. 326
Computer Program for Reinforced Concrete Bar Bending Schedulling to Increase
Efficiency of Reinforcement
W. Hartono, Sugiyarto, S. Marwoto and B. Laksito .................................................................... 332
Assessing Contractor Satisfaction towards Client Performance in Construction
Projects
J. Utomo Dwi Hatmoko and R. Radian Khasani ......................................................................... 338
Structural Condition Assessment of Steel-Framed Maintenance Plant in Muara
Badak, Balikpapan, East Kalimantan
A. Chaerany, A. Awaludin, H. Priyosulistyo and A. Triwiyono ................................................. 344
Chapter 6: Transportation Engineering
The Challenges of Road Preservation Program for Indonesian National Roadway
A. Setyawan and A. Taufik Mulyono .......................................................................................... 359
Impact of Performance Based Contract Implementation on National Road
Maintenance Project to Road Functional Performance
B. Susanti, R.D. Wirahadikusumah, B.W. Soemardi and M. Sutrisno ........................................ 364
Genetic Algorithm Applied for Optimization of Pavement Maintenance under
Overload Traffic: Case Study Indonesia National Highway
A.I. Rifai, S.P. Hadiwardoyo, A.G. Correia and P. Pereira ......................................................... 369
Numerical Analysis on the Deformation of Flexible Pavement System
M. Farid Maruf, S. Wahyuni and J. Widodo ................................................................................ 379
Study on the Properties of Sand Sheet Asphalt Mixture Using Old Road Pavement
Milling and Asphalt Emulsion
I.N.A. Thanaya, I.G.R. Purbanto and I.M.S.J. Negara ................................................................ 385
The Application of Traffic Conflict Technique as a Road Safety Evaluation Method:
A Case Study of Hasselt Intersection
F. Suwarto and K.H. Basuki ........................................................................................................ 394
Water Resistance Evaluation of Asphalt Concrete Wearing Course Made with
Crumb Rubber of Motorcycle Tire Waste
H. Siswanto, B. Supriyanto and L. Abid ...................................................................................... 404
xiii
Applied Mechanics and Materials Vol. 845
Value of Travel Time for Public Transport Passenger in Urban and Intercity Trip
A.M.H. Mahmudah, D. Sarwono, R.I. Pramesty and P.S. Rahina .............................................. 408
Characteristics of Freight Transport Parking and Infrastructures Facilities of
Sustainable Primary Arterial Road (A Case Study of Surakarta Ring Road -
Central Java - Indonesia)
D. Handayani, A.M.H. Mahmudah, S.J. Legowo, A. Arstity Putri and N. Dwi Prasetyo ........... 416
Keyword Index ............................................................................................................................... 423
Author Index .................................................................................................................................. 427
Behaviors of Repaired Edge Column Slab Connections after Punching
Failure Using Normal and Non-Shrinkable (CAH) Concrete
I KETUT Sudarsana
Civil Eng.Dept, Udayana University, Bali, Indonesia
[email protected]; [email protected]
Keywords: Repaired connections, punching failure, flat plate, non-shrinkable concrete, reinforced concrete.
Abstract. Column slab connections in flat plate structures are critical part of the structure. Punching
shear damage to the connections may occur during construction or post moderate earthquakes. To
avoid demolishing overall structures with such damage, connections may be repaired to restore the
original strength of the structures. This paper presents behavior of repaired edge column slab
connections using normal concrete and non-shrinkable (CAH) concrete. Four edge connections of flat
plate structure after failure were repaired using normal and non-shrinkable (CAH) concrete
respectively for two connections. The connections were re-tested to fail under combined shear and
moment. The results show that bonding agent Sika Top Armatec 110 Epocem gave an excellent bond
between the old concrete and the repaired concrete in the tests of repaired edge column slab
connection as there are no cracks observed along the concrete interface. The edge connections
repaired using normal concrete can have similar strength and stiffness as the original connections
when good curing is provided The edge connections repaired using an expansive CAH concrete
exhibited less strength and stiffness compared to the original edge connections due to lack of surface
confinement. The Superplasticizer used in CAH concrete (Mix. B) improves concrete expansion but
reduce the strength of the repaired connections
Introduction
Local damage to the column slab connections of flat plate structures may occur during construction
or post moderate earthquakes [1]. To avoid demolishing overall structures with such damage,
connections may be repaired to restore the original strength of the structures. Concrete in the repaired
connection behaves as a composite material between old concrete and new concrete. According to
[2,3], the strength of composite old and new concrete depends on the bond strength between the new
and old concrete. Factors that affect concrete bond, such as old concrete strength, method of concrete
removal, the interface and the strength of new concrete. Micro cracks due to surface treatment using a
hydraulic jack hammer also affect the bond strength of the interface composite concrete. The fewer
the micro cracks in the old concrete, the stronger the interface composite. However, [2,3] observed
that surface roughness did not have a major influence on bond strength and it was believed that there
might be a threshold value relating the degree of roughness and tensile stress of interface composite
concrete.
Investigation by [4] on repaired damaged connections using epoxy and grout concrete with a
strength of 51 MPa found that the strength of repaired slab-column connections subjected to gravity
and biaxial lateral loads was quite good. Even though the connection lost almost one-half of its
original lateral strength and stiffness, the repaired connection was still able to take approximately the
same horizontal displacement as the original connection. Shear failure of the repaired connection was
observed initially at the interface of the old concrete and grout. This agrees with [2,3] that the strength
of the repaired concrete depends on the bond strength at the interface.
In order to investigate further the behavior of repaired edge column slab connections after
punching failure, this research was conducted. Different methods from [4] were used to repaired
connections using normal and CAH concrete.
Applied Mechanics and Materials Submitted: 2015-07-29ISSN: 1662-7482, Vol. 845, pp 166-174 Revised: 2015-10-06doi:10.4028/www.scientific.net/AMM.845.166 Accepted: 2015-10-06© 2016 Trans Tech Publications, Switzerland Online: 2016-07-25
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TransTech Publications, www.ttp.net. (ID: 114.4.97.218-17/05/16,09:28:59)
Experimental Program
Repaired Edge-Column Connections. Four edge column slab connections of a two bay by two bay
flat plate structure (E1,E2,E3,E4) as shown in Fig. 1 were tested to failure. After the tests, those
connections were repaired using two different types of concrete namely normal concrete and CAH
expansive concrete. The repaired connection were then re-tested to fail under the same loading
scheme as the original connections. The original flat plate model was designed in accordance to [5]
with additional bottom reinforcement at the corner connections. The flat plate thickness was 140 mm,
the interior and corner column dimensions were 305 x 305 mm, the edge column dimensions were
200 x 200 mm. The effective slab depth was 115 mm. Details of the slab reinforcement are shown in
Figure 1a. The 10M (100 mm2) reinforcing bars had a yield strength, fy, of 420 MPa. Other details of
the original specimen can be found in [6,7]
305
2845 2845
28
45
28
45
5@ 90 5@ 907@ 244 3@ 200 70 3@ 200 7@ 244
5@ 90 9@ 226 2@ 127 2@ 127 9@ 226 5@ 905
@9
07
@2
44
3@
20
0
Top Reinforcem ent
Bottom Reinforcem ent
Line of
Sym m etry
75
4@ 127
5@
90
9@
22
63
@1
27
60
75
4@ 1202@ 75
4@ 120
C 5
C 7
C 6
C8
E3 E1
E2
E4
I1
(a) Slab Reinforcement
Laboratoryfloor
Hydrolic
Jack
Slab Specimen
steel column
8" x 8"
steel bracing
3" x 3"
steel base
frame
Hydraulic Jack
Load Cell
Steel 5"x5"
Threaded RodØ3/4"
Hydraulic
Jack
Load Cell
Threaded RodØ3/4"
970
140
508
400
143
994
427
143
Load Cell
(b) Test Set-up
Fig. 1 Layout slab reinforcement and test set-up
In order to repair the damaged connections as shown in Fig.2, the same procedures were used for all
four edge column connections as follows:
♦ The concrete slab around the edge columns was removed after the first test using an electric
hammer. The concrete to be removed from the connection depended on the crack failure of the
connection after the first test.
♦ The loose particles were removed using water pressure.
♦ The surface was sandblasted and cleaned using air pressure.
♦ Formwork was constructed around the repaired connection
♦ The cut surfaces were covered using wet burlap for 24 hours and then dried using air pressure
to be saturated surface dry (SSD) before applying the epoxy adhesive agent to bond the
existing concrete and the repair material.
♦ When the contact surfaces were ready, epoxy adhesive agent was applied. The fresh concrete
was cast approximately one hour after the application of bonding agent.
♦ The concrete was moist cured for 14 days.
Material Properties. Two edge column slab connections E1 and E2 were repaired using a
non-shrinkable concrete produced with Calcium Aluminates Hydrate (CAH) admixture according to
mix design developed by the Institute for Research in Construction of the National Research Council
of Canada (CNRC). Mix.A that contained superplasticizer, was used to repair the E1 connection (E1R)
and Mix.B that without superplasticizer, was used at the E2 connection (E2R). The use of CAH
concrete was to avoid the effect of shrinkage cracks on the interface between new concrete and the
existing one.
Applied Mechanics and Materials Vol. 845 167
The other two edge column slab connections (E3R and E4R), were repaired using Mix.C that was
regular concrete mixed in laboratory. The slump was approximately 75-100 mm. Table 1 presents the
summary of the repair concretes. The repaired connections is identified as E1R, E2R, E3R and E4R to
differentiate from the original connections.
(a) Application of bonding agent before casting
(b) Curing of new casting concrete
Fig. 2. Repaired edge column slab connections
A water based epoxy resin or Portland bonding agent type Sika Top Armatec 110 EpoCem was used
at the interface between the existing/old and fresh concrete. As specified in the manual of the product,
bond strength is about 2-3 MPa when it is used with concrete.
Table 1. Properties of the concretes used to repair the edge column slab connection of the continuous
flat plate specimen
Repaired
Connections Type of
Concrete Mix
Average
compressive
strength (fcm)
Average modulus
of elasticity (Ecm) f’c ( 0.8fcm ) εom
E1R Mix.A 40.0 MPa 25.9 GPa 32.0 MPa 0.00246
E2R Mix.B 39.8 MPa 28.5 GPa 31.9 MPa 0.00261
E3R Mix.C 40.3 MPa 48.0 GPa 32.2 MPa 0.00181
E4R Mix.C 42.7 MPa 40.6 GPa 34.2 MPa 0.00195
Test Setup for Repaired Edge Connection. The test setup for testing of the repaired connections
was similar to that of the original edge connections as shown in Fig. 1b. Two types of loading systems
were used to test the repair connections. The E3R connection was tested twice. The first test was
subjected to vertical load only (E3R*) and the second test (E3R) was subjected to combined vertical
load and bending moment about the axis parallel to the free edge. The test setup for E3R was also
applied to the connections E1R, E2R and E4R. The vertical load increment was 10 kN for all
connections. The moment was increased by increasing the horizontal load in increments of 1 kN, 2 kN
and 3 kN, respectively for E1R, E2R and E4R. The load was increased until connection failure.
Results and Discussion
Crack Patterns and Failure Mechanisms. In general, the crack patterns of the repaired edge
connections were similar to the test of the original edge column connections reported previously in
[6,7]. Details on crack development of the connections repaired using normal and non-shrinkable
concrete are given next.
168 Resilience and Reliability of Civil Engineering Infrastructures
Connection Repaired Using Non-shrinkable CSH Concrete. The Connections E1R and E2R
were repaired using a non-shrinkable CAH (Calcium Aluminate Hydrate) concrete to avoid shrinkage
cracks along the repaired joins. Crack patterns of these two connections are slightly different.
The crack patterns of connection E1R after the failure are shown in Fig. 3a and 3b. At a vertical load
of 40 kN, radial cracks and circumferential cracks along the column perimeter propagating through
the slab depth were observed. Few radial cracks were observed before the connection failed in
punching shear under combined loads. The failure loads were 90.5 kN and 9.8 kNm for shear force
and bending moment, respectively. The average angle of inclined shear failure surface was about
19.5o from the slab surface. No torsion cracks were developed during the test.
(a) cracks on the slab tension surface
(b) cracks on the slab free edge
Fig.3 Crack patterns of connection E1R at the failure
In Connection E2R, flexural cracks around the column perimeter, radial cracks and torsion cracks
were observed first at a vertical load of 60 kN. Torsion cracks reached the slab edge progressing
through the slab depth at 90 kN load. Failure occurred at a vertical load of 129.2 kN and bending
moment of 20.8 kNm. The average inclined failure crack angle was 20o to the slab surface. Fig.4a and
4b show the crack patterns of connection E2R after the failure.
(a) cracks on the slab tension surface
(b) cracks on the slab free edge
Fig.4 Crack patterns of connection E2R at the failure
Connection Repaired with Normal Concrete. The connections E3R and E4R were repaired using
normal concrete. The crack patterns and the failure crack patterns of these connections are shown in
Fig. 5a and 5b. On the first test of connection E3R, cracks along the column perimeter were observed
first at a vertical load of 60 kN. Radial cracks originating from the inner column corner and inside
column slab interface were observed at 70 kN load. As the loads were increased, the radial cracks
progressed away from the column faces to the isolated supports. The connection was unloaded at a
vertical load 230 kN without any failure. No torsion cracks were observed up to this load.
Applied Mechanics and Materials Vol. 845 169
The second test of connection E3R was under combined shear force and bending moment about an
axis parallel to free edge. The only additional cracks developed in the second test were torsion cracks;
which were observed at a moment of 12 kNm. No cracks were noticed on the slab along the interface
of the old concrete and the repaired concrete before failure. The connection failed at 129.1 kN vertical
load and 23.4 kNm bending moment. The failure surface was similar to that of connection E1. The
average angle of failure surface was 18.5o to the slab surface.
(a) Cracks on the slab tension surface (b) Cracks on the slab free edge
Fig. 5 Crack patterns of the second test of connection E3R at the failure
(a) Cracks on the slab tension surface (b) Cracks on the slab free edge
Fig.6 Crack patterns of connection E4R at the failure
In the test of connection E4R, radial cracks and circumferential cracks along the column perimeter
were developed at 50 kN and 5 kNm for vertical load and bending moment, respectively. Radial
cracks started from inner column corners and inner column slab interface progressing diagonally and
perpendicular, respectively, toward the supports. Again, no torsion cracks were observed before the
connection failed in punching shear at the combined vertical load of 120.3 kN and bending moment of
17.1 kNm. The failure surface was similar to the other connections with an average failure angle of
19o to the slab surface.
Ultimate Load Capacity. The first test of connection E3R was subjected to shear force only but the
connection was not tested to failure. The connection was unloaded at 230 kN and re-tested under
combined action of shear force and bending moment. Table 2 presents the ultimate load capacity and
failure modes of the repaired connections. All of the connections failed in brittle punching shear (PS)
due to combined action of shear force and bending moment.
The capacity of E1R is lower than E2R although both connections were casted using the same
concrete strength of about 40 MPa. This is due to the existence of superplasticizer and lack of
confinement on slab surface. In a non-shrinkable concrete produced using calcium aluminates
hydrate (CAH), the superplasticizer in the concrete is able to increase concrete expansion due to more
free water available in it. Free water increases the formation of ettringite between aggregate
170 Resilience and Reliability of Civil Engineering Infrastructures
interfaces. Due to no restraint on the top surface of of slab, the repair concrete was free to expand
upwards which weakened the interface zone within the aggregates. It is believed the cause of the
capacity of connection E1R far below the capacity of the original connection E1 presented in [6,7]. The
results of connection E2R is not comparable to original connection E2 due to a different applied M/V
ratio. However, comparison between connection E2R and E1 shows the capacity of connection E2R is
still lower than the original connection E1.
Table 2. Ultimate load capacity of the repaired edge column slab connections
Slabs c1=c2
mm
h
mm ρc2+3h
%
ρc2+1.5h
%
fy
MPa
fcm
MPa
Vu
KN
Mu
kNm
Failure
Mode
Type of
Connections
E1R 203 140 0.9 0.9 420 39.8 90.5 9.8 PS Repair E2R 203 140 0.9 0.9 420 40.0 129.2 20.8 PS Repair E3R
* 203 140 0.9 0.9 420 40.3 230.0 0.0 - Repair
E3R
203 140 0.9 0.9 420 40.3 129.1 23.4 PS Repair E4R 203 140 0.9 0.9 420 42.7 120.3 17.1 PS Repair E1 203 140 0.9 0.9 420 39.8 127.4 34.4 PS Original E2 203 140 0.9 0.9 420 40.0 220.0 - PS Original E3 203 140 0.9 0.9 420 40.3 - 29.2 PS Original E4 203 140 0.9 0.9 420 42.7 116.7 14.2 PS Original
Note: E1R* was not tested to failure
The Connections E3R and E4R were repaired using normal concrete with concrete compression
strengths, at the age of testing, of 40.3 MPa and 42.7 MPa, respectively. Comparing the load capacity
of the repaired connection using normal concrete with the capacity of the original connections as
shown in Table 2 and already presented in [7], it does not differ significantly. The capacity of
connection E4R was even higher than the original connection E4, increasing from 116.7 kN and 14.2
kNm to 120.3 kN and 17.1 kNm for shear force and bending moment, respectively. The results of
connection E3R are not comparable to the original connection E3 since the load and moment applied to
the original connection differed from those applied to the repaired connection.
The connections repaired using normal concrete (Mix.C), no shrinkage cracks were visible as good
curing was applied to the local repaired area. Therefore, the edge connections repaired using normal
concrete can obtain strengths similar to the original connections provided good curing is used.
Out-of-Plane Slab and Stiffness of Repaired Connections. The out-of-plane deflections of the
slab during the test of edge repair connection are shown in Fig.7 to Fig.8. Location of measured slab
deflections is the same as the original connection as given in [6]. The maximum deflection around the
column connection on the first test of connection E3R was 11.2 mm and on the second test was 8.4 mm
including the residual deflection from the first test of 1.9 mm as shown in Fig. 7a and 7b.
0
50
100
150
200
250
-4 -2 0 2 4 6 8 10 12 14
Sh
ear
Fo
rce [
kN
]
Out-of-plane deflection [mm]
LVDT-1
LVDT-2
D.G. #1
D.G. #2
D.G. #3
D.G. #4
D.G. #5
(a) The 1
st test of Connection E3R*
0
20
40
60
80
100
120
140
-4 -2 0 2 4 6 8 10 12 14
Sh
ear
Fo
rce
[kN
]
Out-of-plane deflection [mm]
LVDT-1
LVDT-2
D.G. #1
D.G. #2
D.G. #3
D.G. #4
D.G. #5
Residual Deflection
from 1st test
(b) The 1st test of Connection E3R*
Fig.7 Out of plane slab deflections of Connection E3R*
Applied Mechanics and Materials Vol. 845 171
Fig. 8 Out of plane slab deflection of Connection E4R
In both tests, the deflections are almost linear indicating a constant vertical stiffness of the connection.
The maximum vertical deflection of the slab in the test of connection E4R was 9.9 mm as shown in
Fig.8. After cracks occurred, the deflections increased faster than the loads indicating a reduction in
connection stiffness. The deflection of the connection was similar to that of the original connection
presented previously.
Fig. 9a and 9b present the deflections of the connections repaired using non-shrinkable concrete. In
both graphs, non-linear deflections around the column were obtained starting at low loads. The
non-linear deflections were more pronounced on connection E1R where superplasticizer was added in
the concrete to provide more free water. These behaviors may be explained based on the nature of the
non-shrinkable (expansive) concrete produced by CAH materials. In this type of concrete, the more
free water is available in the concrete, the more spaces to produce ettringite in the aggregate interfaces
are available. However, lack of restraints on the top surface of the slab allowed the concrete to expand
freely in that direction, resulting in microcracks in the concrete. These microcracks may have caused
the non-linear vertical deflections these connections.
0
10
20
30
40
50
60
70
80
90
100
-4 -2 0 2 4 6 8 10 12 14 16 18
Sh
ear
Fo
rce
[kN
]
Out-of-plane deflection [mm]
LVDT-1
LVDT-2
D.G. #1
D.G. #2
D.G. #3
D.G. #4
D.G. #5
(a) Connection E1R
0
20
40
60
80
100
120
140
160
-4 -2 0 2 4 6 8 10 12 14
Sh
ea
r F
orce [
kN
]
Out-of-plane deflection [mm]
LVDT-1
LVDT-2
D.G. #1
D.G. #2
D.G. #3
D.G. #4
D.G. #5
(b) Connection E2R
Fig. 9 Out of plane slab deflections of the connections repaired using CAH concrete
The stiffnesses of the repaired column connections were less than the original connections
presented in [6,7]. It may be due to reinforcement yielding in the original test and micro cracks during
repair. These results are similar to the experimental results of [4] in which there are degradations on
stiffness of repaired connections. The reduction in the connection stiffness can be seen from the
out-of-plane deflection of the slab around the column. Fig. 10a and 10b show the vertical deflection of
the slab on the original test (E1 and E4) and repaired connection tests (E1R and E4R). The stiffness does
not change significantly in connections repaired using normal concrete (E4R). At low loads before the
occurrence of the cracks, the deflection is almost identical. Slight reduction in connection stiffness is
0
20
40
60
80
100
120
140
-4 -2 0 2 4 6 8 10 12 14
Out-of-plane deflection [mm]
Sh
ear
Fo
rce [
kN
]
LVDT-1
LVDT-2
D.G. #1
D.G. #2
D.G. #3
D.G. #4
D.G. #5
172 Resilience and Reliability of Civil Engineering Infrastructures
apparent after cracks occurred. However, significant change in connection stiffness can be observed
for connection E1R as shown in Fig. 10b, where the connection was repaired using CAH expansive
concrete. It is evident that micro cracks occurred in the concrete due lack of restraint to the top surface
of the slab during repair.
(a) Repaired using normal concrete
(b) Repaired using CAH concrete
Fig. 10 Comparisons between out of plane slab deflections of the original and repaired connections
Column Rotation. The column rotations on all tests of the repaired connections are presented in
Fig. 11. The rotations are calculated using the following expression:
Z
bottomtop
col
∆+∆=θ (1)
Where θcol is the column rotation; ∆top and ∆bottom are horizontal deflection on top and bottom column
stub, respectively; Z is lever arm of the two measured deflection (= 826 mm).
The columns in connections E1R and E4R rotated inward due to low applied moment. The maximum
column rotations in connections E1R, E2R, E3R and E4R were -0.006, 0.002, 0.094, -0.003 radians,
respectively. The largest rotation occurred in connection E3R where the connection had been tested
under vertical load only. The existing cracks due to first test of connection E3R* reduced the stiffness
of the connection on the second test (E3R) as indicated by the large rotation of the column stubs.
0
5
10
15
20
25
30
-0.008 -0.006 -0.003 -0.001 0.002 0.005 0.007 0.010 0.012
Mo
men
t (k
Nm
)
Column Rotation (Radian)
Col. E3R
Col. E4R
Col. E2R
Col. E1R
Fig. 11. Column rotations on the tests of repaired connections E1R, E2R, E3R and E4R
0
20
40
60
80
100
120
140
0 2 4 6 8 10 12 14 16
Out-of-plane deflection (mm)
Sh
ea
r F
orc
e (
kN
)
LVDT-1 (E4)
LVDT-2 (E4)
LVDT-2 (E4R)
LVDT-1 (E4R)
0
20
40
60
80
100
120
140
0 2 4 6 8 10 12 14 16 18
Out-of-plane deflection (mm)
Sh
ear
Fo
rce (
kN
)
LVDT-1 (E1)
LVDT-2 (E1)
LVDT-1 (E1R)
LVDT-2 (E1R)
Applied Mechanics and Materials Vol. 845 173
Conclusion
The following conclusion may be drawn from experimental work and analysis of the repaired
connections:
1. There are no cracks observed along the concrete interface indicated that Bonding agent Sika
Top Armatec 110 Epocem used in this study gave an excellent bond between the old concrete
and the repaired concrete.
2. The average angle of failure surface ranges from 18.5o to 20
o to the slab surface.
3. Edge connections repaired using normal concrete can have similar strength and stiffness as the
original connections when good curing is provided.
4. The edge connections repaired using an expansive CAH concrete exhibited less strength and
stiffness compared to the original edge connections due to lack of surface confinement.
5. The Superplasticizer used in CAH concrete (Mix. B) improves concrete expansion but reduce
the strength of the repaired connections.
References
[1] N.J. Gardner, J. Huh, and L. Chung: What Can We Learn from the Sampoong Department Store
Collapse, International Workshop on Punching Shear Capacity on RC Slabs-Proceedings, Royal
Institute of Technology, Stockholm, June (2000), pp. 225-233.
[2] J. Silfwerbrand: Improving concrete bond in repaired bridge decks, Concrete International,
September (1990), pp 61–66.
[3] J. Silfwerbrand: Shear Bond Strength in Repaired Concrete Structures, Materials & Structures,
Vol. 36 (2003), pp. 419-424
[4] A.D. Pan and J.P. Moehle: An experimental study of slab-column connections, ACI structural
journal, Vol.89 No. 6 (1992), pp. 626-638
[5] CSA-A23.3-M94: Design of Concrete Structures for Buildings, Canadian Standard Association,
December (1994)
[6] I K. Sudarsana: Punching shear in edge and corner column slab connections of flat plate
structure, PhD thesis, University of Ottawa (2001), 224 pp.
[7] I K.Sudarsana and N.J Gardner: Punching shear in edge column slab connections of flat plate
structures, 2nd
ACF Conference, Bali, Indonesia, November (2006).
174 Resilience and Reliability of Civil Engineering Infrastructures
