Deftec-tion of Pesheard Corrrete memobers
Defiechion is detined aj the disblacement o point on
a
a toaded slneturat member.
h e deflection a member is caleuloted at teast Por
tut Cabes
hort tem dellechion ot ttanster
Long tem delleetien under seivice loods
hert term deftection at ttansfer
due to -the presressinq force.4 self weight
Jhe elet o Cteep and shrinkage
not Conside ted.
ot Concrefe are
Long term deflection under Service loadl
due te effective preStressing force 4 gravit loads.
he effect el cree and shrinkage o concrete are
Considere
Creeb- mcrease in detormation utth time unoler
Constant toad.
brinKage- Conttaction due te loss omeisture.
Retaxation ok steel- Decreoase in stress under
Cnsfant Strain.
,factors affecting defection-
San Gs the span inceases, the delltection alse ireoses
Modulus elasiicity CorhCiele -
esthe strergth e Concrete thcteases, its mooulus
o
elati city alse inc reases and dellection decreases.
ubet impased load s the
magnitude o
uber imþosed land increales, the
deflcion also increase
Pre-stess -fs the magnitude
oPie- sthes increases,
the amourt e deflction decteases.
lomant o inertia- 4s he momert
ctoss-section indeale), the amourt oinertia. ot the
dectease3
odeflecthion
Creeb and Shrinkage e conctete
hese factors hove sighifi cart intluebce
long on term
deftection, in portieular as the creep Concree
the deltection also inrease). incrases,
Limits of Deflection -
Ctause 19.8:1 of 19:13413-2019
h e tstal delection due to all toads , including the
effects of temperature, creep and shrinkage
Should not ex ceed span 950.
h e dellection ofter erection o} Partitions or apblicaflon
of inushes,incuding the effet o temperatune, creeb
0,
and shrinkage .should not exceecd span 350 or
90mm,
whichever is les
inishes are aphlied,tetal upard delectin due t
pre- stressing fbrce should rest exceed san 3 0o.
, SHORT TERM DEFLECTIONg AT TRANSFER
/Bending
momet
dagrom.
A B
langent at A
Tanget at C
Slope and
cellection e} Beam
Consider beam AB subfected ta a bencding moment
distnibution due te pre stress ing force or self-
-
tmpased toadg
weight or
ACB is the cette line ef the defomed sttuchure under
the system o given loods.
eccording to Mobr's first Slope st elastic cumect A
theorem AD = Jrtercept betueen the
BMD fangent at c and the
8lope irea e
=
Vertical at A
Flexural Rigidit/
8 Deflection at the centre
for symnetrially oaded,
Simply stupborta becam
fMohrs Second theorem
A Area o the BMD bJo A¢c
Stcdes thot.
cept,
ter cept,8-
trter IMomert oforaof= distance
of the Centreicd sl
BMD the BMD b/w A fc from
Flexural Rigididy) the teft support.
AAx EI flexural rigitity ot the
E beam
Defiechion is detined aj the disblacement o point on
a
a toaded slneturat member.
h e deflection a member is caleuloted at teast Por
tut Cabes
hort tem dellechion ot ttanster
Long tem delleetien under seivice loods
hert term deftection at ttansfer
due to -the presressinq force.4 self weight
Jhe elet o Cteep and shrinkage
not Conside ted.
ot Concrefe are
Long term deflection under Service loadl
due te effective preStressing force 4 gravit loads.
he effect el cree and shrinkage o concrete are
Considere
Creeb- mcrease in detormation utth time unoler
Constant toad.
brinKage- Conttaction due te loss omeisture.
Retaxation ok steel- Decreoase in stress under
Cnsfant Strain.
,factors affecting defection-
San Gs the span inceases, the delltection alse ireoses
Modulus elasiicity CorhCiele -
esthe strergth e Concrete thcteases, its mooulus
o
elati city alse inc reases and dellection decreases.
ubet impased load s the
magnitude o
uber imþosed land increales, the
deflcion also increase
Pre-stess -fs the magnitude
oPie- sthes increases,
the amourt e deflction decteases.
lomant o inertia- 4s he momert
ctoss-section indeale), the amourt oinertia. ot the
dectease3
odeflecthion
Creeb and Shrinkage e conctete
hese factors hove sighifi cart intluebce
long on term
deftection, in portieular as the creep Concree
the deltection also inrease). incrases,
Limits of Deflection -
Ctause 19.8:1 of 19:13413-2019
h e tstal delection due to all toads , including the
effects of temperature, creep and shrinkage
Should not ex ceed span 950.
h e dellection ofter erection o} Partitions or apblicaflon
of inushes,incuding the effet o temperatune, creeb
0,
and shrinkage .should not exceecd span 350 or
90mm,
whichever is les
inishes are aphlied,tetal upard delectin due t
pre- stressing fbrce should rest exceed san 3 0o.
, SHORT TERM DEFLECTIONg AT TRANSFER
/Bending
momet
dagrom.
A B
langent at A
Tanget at C
Slope and
cellection e} Beam
Consider beam AB subfected ta a bencding moment
distnibution due te pre stress ing force or self-
-
tmpased toadg
weight or
ACB is the cette line ef the defomed sttuchure under
the system o given loods.
eccording to Mobr's first Slope st elastic cumect A
theorem AD = Jrtercept betueen the
BMD fangent at c and the
8lope irea e
=
Vertical at A
Flexural Rigidit/
8 Deflection at the centre
for symnetrially oaded,
Simply stupborta becam
fMohrs Second theorem
A Area o the BMD bJo A¢c
Stcdes thot.
cept,
ter cept,8-
trter IMomert oforaof= distance
of the Centreicd sl
BMD the BMD b/w A fc from
Flexural Rigididy) the teft support.
AAx EI flexural rigitity ot the
E beam
