Quiz: CIVIL ENGINEERING

Exam: TELANGANA-PSCM

Topic: L.S.M. & W.S.M.

Each question carries 1 mark

Negative marking: No negative marking

Time: 10 Minutes

Q1. What shall be the total strain in Fe 415 grade steel corresponding to the stress of 0.87 fy?

(a) 0.0035

(b) 0.0038

(c) 0.002

(d) 0.004

L1Difficulty 2

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q2. Stress-strain curve of concrete is

(a) a perfect straight line upto failure

(b) straight line upto 0.002 strain value and the parabolic upto failure

(c) hyperbolic upto 0.002 strain value and a straight line upto failure

(d) parabolic upto 0.002 strain value and a straight line upto failure

L1Difficulty 2

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q3. The factor of safety for steel as compared to concrete is ……………

(a) Higher

(b) Same

(c) Lower

(d) None of these

L1Difficulty 1

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q4. According to Whitney’s theory, ultimate strain of concrete is assumed to be

(a) 0.03%

(b) 0.1%

(c) 0.3%

(d) 1%

L1Difficulty 3

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q5. In limit state of collapse against flexure, the maximum strain in tension reinforcement at failure shall not be less than

(a) 0.002

(b) 0.002 + fy/Es

(c) 0.002 + fy/(0.87 Es )

(d) 0.002+fy/(1.15 Es )

L1Difficulty 3

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q6. Flexural collapse in over reinforced beams is due to

(a) primary compression failure

(b) secondary compression failure

(c) primary tension failure

(d) bound failure

L1Difficulty 2

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q7. Equivalent area of a reinforced cement concrete section is:

(a) m Ac+Asc

(b) Ac+m Asc

(c) Ac+Asc

(d) (Ac+m Asc ) σc

L1Difficulty 2

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q8. Minimum tension steel in RCC beam needs to be provided to:

(a) control excessive deflection

(b) control surface cracks

(c) prevent sudden failure

(d) none of the above

L1Difficulty 3

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q9. As per the working stress method of reinforced concrete design, if a concrete has permissible compressive stress of p, then the modular ratio is approximately given as:

(a) 93/p

(b) 140/p

(c) 210/p

(d) 280/p

L1Difficulty 2

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

Q10. Generally, strength of concrete is considered negligible/ very low in

(a) Compression

(b) Tension

(c) Fatigue

(d) None of the above

L1Difficulty 2

QTags Reinforced Concrete Cement (RCC)

QCereator Anubhav Gupta

SOLUTION

S1. Ans.(b)

Sol. Strain in HYSD bars (fe415)

=0.002+0.87fy/Es

=0.002+(0.87×415)/(2×10^5 )⇒0.0038

Strain in mild steel = (0.87×fy)/Es

=(0.87×250)/(2×105)=0.00108

S2. Ans.(d)

Sol.

According to IS. Code stress strain curve is parabola up to 0.002 then straight line

Up to failure.

S3. Ans.(c)

Sol. factor of safety of steel ⇒1.15

Factor of safety of concrete ⇒ 1.5

→ Due to variability in strength of concrete due to poor quality control, poor work man ship etc, higher factor of safety is given for concrete in comparison to steel.

S4. Ans.(c)

Sol. According to Whitney’s theory, ultimate strain of concrete is 0.003 (0.3%)

S5. Ans.(d)

Sol. maximum strain in tension reinforcement

Steel grade Strain

Fe-250 0.87fy/Es

Fe-415 0.002+0.87fy/Es

Fe-500 0.002 + 0.87fy/Es

For HYSD bar’s maximum strain in tension Reinforcement

=▭(0.002+0.87fy/Es )

Or

=▭(0.002+fy/(1.15 Es ))

S6. Ans.(a)

Sol. flexure collapse in over reinforced beams is due to primary compression failure.

S7. Ans.(b)

Sol. Equivalent area of reinforced cement concrete

▭(A=Ac+m.Asc)

Ac→Area of concrete

Asc→ Area of steel

S8. Ans.(c)

Sol. → Minimum reinforcement provided in beam to avoid any possibility of sudden failure due to over loading.

→ Maximum reinforcement is restricted because it result in congession effect proper compaction & placement of concrete.

S9. Ans.(a)

Sol. modular ratio (m) =280/3σcbc

▭(σcbc=p)

M=280/3p

▭(m=93/p)

S10. Ans.(c) → The strength of concrete in fatigue is negligible.

→ Strength of concrete in tension is 10 to 15% of compressive strength.