Enginesrirug
Sewices
Examination-201
3

Serial
No.

I

CIVIL
ENGINEERING
AFRFMBUA

Paper-I
(Conventional)

Time/éllloweud
.'
Three
Hours

Maximum Marks .'
200

INSTRUCTIONS

Pleaseread each ofthie follo wing:instructions
carefully before attemptingquestions :

Candidates
shouldattemptFIVE questionsin all.

QuestionNo.
1 is compulsory.
Outof theremaining
SIX questionsattempt any FOUR.

All questions
carryequalmarks.Thenumber
of
markscarriedbyapart of aquestion
is indicated
against it.

Answersmustbe written in ENGLISH only
Unlessotherwisemjentioned,h
symbolsand notations

have
theirusualstandard
meanings.

I

Assumesuitabledata, if necessaryand indicate
the sameclearly.

'
Neat sketchesmaybe drawn,awhereverrequired.
All parts and sub-partsof a questionare to be
attempted together in the answer book.

Any pagesleft blank in the answerbookmustbe
clearly struck out.

All partscarryequalmarks:

10><4=40

(a) Cementis madeof solid complexesof oxidesof
calcium

etc. Write the names of the four well

known complexesalong with the notation used

to representthese.

4

(b) Writethefull formof thefollowing
in context
of
civil engineeringconstruction,:
(i)

4><l--4

RMC

(ii) GIS
&#39;*(ii&#39;i)
BOLT
(iv) BOQ

(0.) Draw the bendingmomentdiagramof a beam
from the shear force diagram of the beam.

4

(d) Drawthedifferent
mechanisims
fortheframe
as
shown in the fig. for plastic analysis.

2
+

4

(Contd.)

(e) (i) Name10commonly
usedhotrolledstructural
section for steel construction.

2

(ii)Give
06
reasons
for
failure
ofrivetted
joints.
2
(t) A simply supportedrectangularbeamof le_ngthL
carriesa udl over its entire length. Determinethe

critical lengthat which the shearingstressTo
andflexuralstress<5reachtheir allowablevalues
simultaneously.
The breadthof beamsectionis
aband depth is d.

4

(g) A beamof square(sectionof theside a is placed
such that (i) two sides are horizontal (ii) one
diagonal is horizontal. Find the ratio of the .

moments
of resistance
of thesection
in twopositions
for samepermissiblebendingstress.

4

(h) Determinethe moment of resistanceof a Tee-

sectionhavingthe followingproperties:
Flange Width = 2000 mm
Flange Depths= 100 mm
Web Width = 250 mm

Effective Depth = 750 mm
Area of Steel = 8 bars of 20 mm diameter

Material used = M25 grade of cone and
Fe4715 HYSD bars.

4

(i) An aluminiumshaftwith a constant
diameter
of
50 mm is loaded by torques applied to gears
attachedto it as shown in Figure below. Using
G = 28 GPa,determinetherelative anggleofttwist

of gearD relativeto gearA.

&#39;4

(Contd.)

2.

(3) A site is using a concretewhere the unit content

of water,cement,sandandcoarseaggregate
is

130kg/I113,
360kg/m3,
700kg/m3
and.1210
kg/m{
respectively.
Foraportionof theworlgthie
Engineer
permitsvolume batchingand rectangularboxes
measuring35 cm by 45cmhave to be fabricated
to measure coarse aggregate.

Assumethe following :

I (i). Themixeravailablewillmixconcrete
with
onebagof cement(of 50 kg) at onetime.
(ii) 2 (two) boxesof coarse.
aggregate
will be
usedin a batch(as definedabove).

(iii) "When
filledin a normalmanner,
thevoid
content in the box is 40%.

&#39;

(iv) Specicgravityof the coarseaggregate
is
2.75.

Find the height of the box.
(b)

10

Corrosionof reinforcelnentin
reinforced
concrete
construction is matter of serious concernto civil

engineers.
List and briey discusssomeof the

provisions
madein codes(suchasIS 456-2000)
to address
this problemduringthe designand
construction
of structures
likely to besubjected
to such deterioration.

10

(ca)Writeashornt
answer
to thefollowing
:
20
(i) When
testing
cements
asperIndian
Standards,
it may not be possibleto decideon their

qualityonlyjonthebasisof thecompressive
strengthresults. Why .7
5
4*

(Contd.)

(ii) What
aresome
ofthesteps
thatcanbetaken
to preventthe formationofither1nalcracks
in mass concrete ?

(iii) Explaintheconcept
of maturityof concrete.
(iv) IS 456-2000suggests
useof a certainstressstrain curve of concrete in the absenceof

actualexperimental
data,Thecodealsoallows

use
ofanexpression
(5000
N/fck)&#39;to
estirnate
the modulusof elasticityoftconcrete
(EC).
Draw a neat representationof that curve,
briey explain its salient features. The

suggested
valuerepresents
thevalueof E at
which, if any, of the point(s) on the stressstrain

curve.

(a) Compute
thetotalelongation
caused
byan axial
loadof 100kN appliedto a at bar20 mmthick,

tapering
froma Widthof 120mmto 40 mmin
a lengthof 10amas shownin gure. Assume
E = 200 GPa.

20
20 mm thick
60mm

60mm

6 .

(Contd.)

(b) Fortherigidframesjhown
in gureb.el,0w,,
find

by (unitloadmethod,the slopes:and d&#39;e&#39;ecti.

at A and
96 KN

48

(a) Detstign
atisuitablesectionfor steeltplatebeam
girder carrying a tuniformltydiistributedload"of
60 kN/m (irmludintgt
seilfweiight)overanJeffective

spanof 15 int.»check for shearand deection
also. Use limit

stjaftemethod of ideistign.U*s£=

0 @145.1
kgf/m I =1061985
C1114
and1 =4702.5
c;m4.
20
(b)

5 m effectiveSP3-"I1
simplysupported»
bealllis

subjected
toa loadof 40mzminctluditngiititsvself
weight.Thesizeof the
is 250 X 500
Thebeamis retiinfolrced
with 420 39at bottom
7
,

(Contdi.)

(out of which two barsarecurtailed)and 212~ii
at top. Design the beam against shear force and

show the reinforcement details. Use M20 and

F6415.Uselimit statemethodof design.

T
a(MP3)
1.5

1::(MP3)

0.67 0.72 0.79 0.82 0.32
20

5.

(a) Find the member forces in the member marked
A, B and C for the truss as shown.
5rl(N

A=

l0kN

l0kN10kN

10

5kN

6bays@3m:=
18m

(be) A rigid bent ABC is of uniform cross-sectionand

is in a horizontal plane. It is fixed at1Aand free

at C asshowninFig. It carriestwo verticalloads

10 kN each at B and C. Draw Bending moment,

shcear
force
and
torsional
moment
inthe
bent
10

(c) A plate is connected to the ange of an ISMB as
shown.

The factored

load is 100 kN.

Find

the

sizeof the weld.Assumeshopweld andultimate
strength of weld as 410 MPa.

20

I

Pull:
100
kN
300

(a) A concrete beam simply supported at both ends

with a rectangularsection300 mm X 600 mm is
prestressed by-2 post tensioned cables of area

500mm2each.Thecablesarelocatedat a constant)
eccentricity of 1000mm throughout the beamsof

span8 m. The cables are stressedto 1600 MPa.
initially. Calculate the deection of the beam

(maximum) when it carries an imposed load of
20 kN/m allowing 20% loss in prestress.Assume
the modulus of elasticity of concrete and steel

are30000MPaand2 x 105.MParespective.ly.,
Neglect the effect of shrinkageand creep.

10

(b) Determine the collapse load of the beam as shown
below. E1 = constant.
W

%
l,

V1m

I:

10

W

2 111

1,

2W

lm

I,

2 m

|:

1 In

l,

(c) Find theend moments of the frameshown below.
Use Moment Di&#39;s-tribution&#39;
method. Also draw
BMD.

.20

10

(Contd.)

7.

(a) In a small project, three activities, A, B and C,
are on the critical path. Their optimistic, most

likely and pessimistic time durations (weeks) is
given below :

Assuming that the non-critical, activities are
completed within that time :

(i)

What is the probability that the project can
be completed in 29 weeks I

(ii) What is the probabilitythat the projectcan
be completed in 27 weeks&#39;?
For a probability of 10%, 20% and 30% the Z
values may be taken to be 1.26, ,0.84 and 0.53,
respectively.
10.

(b) Safety precautionsto be taken at a construction
site are related to the nature of the construction

activity. Discussthis statementwith appropriate
examples.

10

(c) Aspartof routine
quality
control,a
sample
of
cubesis takten
om a siteusingM30concrete.
The-cubesare appropriatelycuredandtestedfor
H
O

(Contd.)

their compressive strength. The values obtained
for the three cubes are : 31 MPa, 28 MPa and
23 MP3.

Based on the provision of IS 456-2000, answer

the following»:
(i)

Does the above constitutea valid set of results

fromthepointofViewof acceptance
?Justify
your

(ii)

answer.

acceptable? Clearly indicate:if any additional

informationmay be neededbeforea nal
decision on acceptance is made.
(d)

Are)

10

Is the concreterepresented
by the
results
Explainrwithrappropriate
sketcheshow
a trernie
is used to place concreteunderwater.

05s

Explain briey the highlighted terms in the
following sentence. (not more than 20 words)

The contractorandthe client agreedto sendthe

matter
forarbitration-.
OR

The contractor was informed that the plea of force
majeure for thedelay in the completion was not
acceptable.
.
5