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April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 2
Introduction
� This presentation is intended toshed the light on the nature of the Shortening criterion in concrete, the method of predictionand application of information.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 3
TYPES OF SHORTENING
� Elastic shortening (instant)
� Shrinkage- Drying shrinkage (instant)- Autogenous shrinkage (time dependant).
� Creep (time dependant)
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 4
FACTORS AFFECTING SHORTENING
1 – ELASTIC SHORTENING
� Strength of concrete.
� Age of loading.
� Magnitude of loading
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 5
FACTORS AFFECTING SHORTENING
2 – SHRINKAGE
� Ambient humidity.
� Dimensions of element.
� Composition of concrete.
SHRINKAGE DOES NOT DEPEND ON LOADING
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 6
FACTORS AFFECTING SHORTENING
3 – CREEP
� Ambient humidity.� Dimensions of element.� Composition of concrete.� Strength of concrete.� Magnitude of sustained load.� Age of loading.
CREEP IS DEPENDANT ON SUSTAINED LOADING
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 7
MONITORED OBJECTS
Shortening is being predicted and monitored for all “Vertical
Structural Elements”,That is:
COLUMNS and
COREWALL ELEMENTS
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 9
LET’S LOOK AGAIN AT THAT LAST IMAGE….
Long term Shortening yet to take place AFTER PLACEMENT is the key figure to assess impact.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 10
LONG TERM SHORTENING YET TO TAKE PLACE AFTER PLACEMENT
� Long term Cumulative shortening for a column at level 30, starts well before placement date.
� Long term cumulative shortening yet to take place at that point equals:
Long term cumulative shortening at that point LESS Interim Cumulative Shortening that has already taken place at time of pouring the slab.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 11
WE NEED TO AGREE ON THE DEFINITION OF THE TERMS
JUST MENTIONED:
� Final floor Shortening: “FFS”Is the final (30+ years) shortening for a “VSE” at a given level.
� Final Cumulative Shortening “FCS”: Is the final (30 + years) and cumulative shortening for all the VSEsunderneath a point at a given level.
� Interim Cumulative Shortening “ICS”: Is the cumulative shortening for all the VSEs underneath a Target Point at a given time.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 12
MORE DEFINITIONS
� LEVEL ADJUSTMENT:
Floor slab should be constructed to a higher level than that designed such that design level would be reached to upon completion of final shortening.
Adjustment at a given level should be equal to the “Cumulative Shortening” yet to take place for all columns underneath that level from the date of slab placement and for 30 years to come after loading completion.
Level Adjustment = Final (30 Y) Cumulative Shortening at the point less the “Interim Cumulative Shortening at time of placement = FCS – ICS.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 13
WHY DO WE NEED TO PREDICT SHORTENING ?.
� To determine the level adjustment amount.
� To assess the impact on interfacing structures.
� To establish construction tolerance in interfacing installations (cladding, pipe risers, vertical railing ..etc) .
� To assess the impact of column / core wall differential shortening on the structure.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 14
CALCULATION METHODOLOGY
The magnitude of long term elastic, shrinkage and creep strains has been calculated as per the provisions of BS EN 1992-1-1:2004.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 15
PREDICTION METHODOLOGY 1 - ANALYSIS PARAMETERS
SHORTENING CALCULATIONS TO THE REQUIREMENTS OF "EUROCODE 2, BS EN 1992-1-1:2004
RH Relative Humidity % age
����H
A coefficient depending on the relative 1.5[1+(.012 RH)18] ho + 250 ����3 , <= 1500 ����3
humidity & member size - for fcm => 35
t0 Age of concrete at loading
����c Compressive stress applied at age to
ho Section notional size = 2 Area / Perimeter
t Age of concrete at the moment)
t-t0 Non-adjusted duration of loading
����cc(t)Cefficient for the calculation of
exp{s[1-(28/t)1/2]} = e{s[1-����(28/t)]}
compressive strength fcm(t) at age t
fcm(t) Compressive strength at age t ����cc(t). fcm
Ecm Concrete secant modulus of elasticity 22 (fcm/10)0.3
Ecm(t) Tangent Modulus of Elasticity at age "t" [fcm(t) / fcm]0.3 .Ecm
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 16
PREDICTION METHODOLOGY 2 - ELASTIC SHORTENING
����e����t���� Elastic strain at time "t" ����c / Ecm(t)
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 17
PREDICTION METHODOLOGY 3 - DRYING SHRINKAGE
����RHCoefficient related to relative humidity 1.55 [1 - (RH/RHO)3]
����ds1 Coefficient depends on cement type
����ds2 Coefficient depends on cement type
����cd.0 Basic drying shrinkage strain
0.85[(220+110.����ds1).
exp(-����ds2.fcm/fcmo)].����RH/106
����ds(t,ts)(t-ts)
(t-ts)+0.04����ho3
kh Coefficient depending on "ho" Equals 0.7 for ho =>500
����cd (t) Long term drying shrinkage ����ds(t,ts).kh.����cd.0����ca (����) 2.5(fck-10)106
����as(t) 1 - exp(-2t0.5)����ca (t) The autogenous shrinkage ����as(t) . ����ca (����)
����cs Total shrinkage strain ����cd + ����ca
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 18
PREDICTION METHODOLOGY 4 - CREEP
Ec Tangent Modulus of Elasticity. 1.05 Ecm
����1 ����1��������2,����3 are coefficients to (35/fcm)0.7
����2 consider the influence of the (35/fcm)0.2
����3 concrete strength on the creep strain. (35/fcm)0.5
����(to) A factor allowing for age of loading effect. 1 / (0.1 + to0.2)
����(fcm)A factor to allow for the effect of concrete 16.8
strength on the notional creep coefficient ����fcm
����(t,to) A coefficient to count time effect [(t-t0) / (����H + t - t0)]0.3
����RH A factor to allow for the effect of humidity. [1+(1-RH/100).����1/(0.1 ho^0.333)].����2
����0 Notional creep coefficient ����RH . ����(fcm). (����(t0)
��������t,to���� The creep coefficient. ���� . ����c(t,to)
����cc����t,to���� Creep deformation (strain) at time "t" ��������t,to������������c����Ec����
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 19
THE MASTER SPREADSHEET
Data base for geometric, material and loading information for each column / corewall element, including the construction schedule, has been entered into a Master Spreadsheet.
Cells of the Master Spreadsheet encapsulate the formulae needed to calculate the strain in the column corresponding to following loadings imposed by floor slabs supported by the column:
� SWL : Self Weight Load.� SDL : Super-imposed Dead Load.� SLL : Super-imposed Live Load.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 20
MASTER SPREAD SHEET - INSERTING CONSTRUCTION SCHEDULE
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 21
MASTER SPREAD SHEET - INSERTING COLUMN PROPERTIES
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 22
MASTER SPREAD SHEET – PART 1
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 23
MASTER SPREAD SHEET – PART 2DETAIL “A”
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 24
MASTER SPREAD SHEET – DETAIL “A”
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 25
MASTER SPREAD SHEET – GETTING A SHORTENING VALUE ON A GIVEN DATE
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 27
LEVEL ADJUSTMENT ACHIEVED
� To determine the level adjustment amount.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 28
MASTER SPREAD SHEET – GETTING A COLUMN PROFILE AT A GIVEN LEVEL
PREDICTED PROFILE FOR C1- L 30 TOP
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
28-J
an-0
8
28-F
eb-0
8
28-M
ar-0
8
28-A
pr-
08
28-M
ay-0
8
28-J
un
-08
28-J
ul-
08
28-A
ug
-08
28-S
ep-0
8
28-O
ct-0
8
28-N
ov-
08
28-D
ec-0
8
28-J
an-0
9
28-F
eb-0
9
28-M
ar-0
9
28-A
pr-
09
28-M
ay-0
9
28-J
un
-09
28-J
ul-
09
28-A
ug
-09
28-S
ep-0
9
28-O
ct-0
9
28-N
ov-
09
28-D
ec-0
9
28-J
an-1
0
28-F
eb-1
0
28-M
ar-1
0
28-A
pr-
10
28-M
ay-1
0
PREDICTED
FINAL
MEASURED
CHART NO. C3-L30-04009-01 COLUMN C3 POINT AT L 30 DATE 3-Jun-08
April 09
THE
LAN
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N29
MASTER SPREAD SHEET –
IMPACT OF SHORTENING
ON INTERFACING STRUCTURES (THE CANOPY)
-70.0
0
-60.0
0
-50.0
0
-40.0
0
-30.0
0
-20.0
0
-10.0
0
0.0
0
9-Feb-08
9-Mar-08
9-Apr-08
9-May-08
9-Jun-08
9-Jul-08
9-Aug-08
9-Sep-08
9-Oct-08
9-Nov-08
9-Dec-08
9-Jan-09
9-Feb-09
9-Mar-09
9-Apr-09
9-May-09
9-Jun-09
9-Jul-09
9-Aug-09
9-Sep-09
9-Oct-09
9-Nov-09
9-Dec-09
9-Jan-10
9-Feb-10
9-Mar-10
9-Apr-10
9-May-10
9-Jun-10
-140.0
0
-120.0
0
-100.0
0
-80.0
0
-60.0
0
-40.0
0
-20.0
0
0.0
0
26-Apr-08
26-May-08
26-Jun-08
26-Jul-08
26-Aug-08
26-Sep-08
26-Oct-08
26-Nov-08
26-Dec-08
26-Jan-09
26-Feb-09
26-Mar-09
26-Apr-09
26-May-09
26-Jun-09
26-Jul-09
26-Aug-09
26-Sep-09
26-Oct-09
26-Nov-09
26-Dec-09
26-Jan-10
26-Feb-10
26-Mar-10
26-Apr-10
26-May-10
26-Jun-10
26-Jul-10
26-Aug-10
A B
PROFILE AT L-7
PROFILE AT L-1
INT
ER
FAC
ING
STR
UC
TU
RE
LO
NG
TE
RM
DIM
EN
SION
AL
CH
AN
GE
��� �H
= A –
B = 4.9 m
m
INT
ER
FAC
ING
STR
UC
TU
RE
INST
AL
LA
TIO
N C
OM
PLE
TIO
N
14 APR
IL 2010
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 30
IMPACT ON INTERFACING STRUCTURES ASSESSED.
� To determine the level adjustment amount.
� To assess the impact on interfacing structures.
April 09
THE
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N31
MASTER SPREAD SHEET –
IMPACT OF SHORTENING
ON INTERFACING INSTALLATIONS (CURTAIN WALL)
-350.0
0
-300.0
0
-250.0
0
-200.0
0
-150.0
0
-100.0
0
-50.0
0
0.0
04-Dec-08
4-Jan-09
4-Feb-09
4-Mar-09
4-Apr-09
4-May-09
4-Jun-09
4-Jul-09
4-Aug-09
4-Sep-09
4-Oct-09
4-Nov-09
4-Dec-09
4-Jan-10
4-Feb-10
4-Mar-10
4-Apr-10
4-May-10
4-Jun-10
4-Jul-10
4-Aug-10
4-Sep-10
4-Oct-10
4-Nov-10
4-Dec-10
4-Jan-11
4-Feb-11
4-Mar-11
4-Apr-11
A
B
PROFILE AT L-36 PROFILE AT L-35
INT
ER
FAC
ING
STR
UC
TU
RE
LO
NG
TE
RM
DIM
EN
SION
AL
CH
AN
GE
��� �H
= A –
B = 2.1 m
m
INT
ER
FAC
ING
INST
AL
LA
TIO
N C
OM
PLE
TIO
N
20 APR
IL 2010
-350.0
0
-300.0
0
-250.0
0
-200.0
0
-150.0
0
-100.0
0
-50
.00
0.0
0
24-Dec-08
24-Jan-09
24-Feb-09
24-Mar-09
24-Apr-09
24-May-09
24-Jun-09
24-Jul-09
24-Aug-09
24-Sep-09
24-Oct-09
24-Nov-09
24-Dec-09
24-Jan-10
24-Feb-10
24-Mar-10
24-Apr-10
24-May-10
24-Jun-10
24-Jul-10
24-Aug-10
24-Sep-10
24-Oct-10
24-Nov-10
24-Dec-10
24-Jan-11
24-Feb-11
24-Mar-11
24-Apr-11
A
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 32
CONSTRUCTION TOLERANCE IN INTERFACING INSTALLATION VERIFIED
� To determine the level adjustment amount.
� To assess the impact on interfacing structures.
� To establish construction tolerance in interfacing installations (cladding, pipe risers, vertical railing ..etc) .
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 33
THE EXECUTIVE SUMMARY
Information extracted from various Master Spreadsheets has
been classified sorted in 5 schedules A through E.
These schedules were listed in an “Implementation Duty
Matrix” along with a listing for their
functions and concerned parties.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 35
SCHEDULE A
A summary for 30 years final
cumulative shortening
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 36
SCHEDULE B
Balance Final Cumulative
Shortening yet to take place
after placement of VSEs
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 37
SCHEDULE C
Change in inter-floor
height
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 38
SCHEDULE D
Floor level adjustment
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 39
SCHEDULE E
Differential shortening
between corewall & columns at
pivots.
April 09THE LANDMARK ABU DHABI – ALHABTOOR CCC JV
SHORTENING PREDICTION 40
COLUMN / COREWALL DIFFERENTIAL SHORTENING COMPUTED.
� To determine the level adjustment amount.
� To assess the impact on interfacing structures.
� To establish construction tolerance in interfacing installations (cladding, pipe risers, vertical railing ..etc) .
� To assess the impact of column / core wall differential shortening on the structure.