Question Paper: Limit state Method for Reinforced concrete stuctures Question Paper - May 17 - Civil Engineering (Semester 7) - Mumbai University (MU)
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## Limit state Method for Reinforced concrete stuctures - May 17

### Civil Engineering (Semester 7)

Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question No. 1 is compulsory
(2) Answer any three from the remaining
(3) Draw neat diagrams wherever necessary

1(a) Distinguish between One Way Slab & Two Way Slab.
(5 marks) 00

1(b) A beam (300 mm x 600 mm) is reinforced with 2 bars of 25 mm diameter. Find the Ultimate Moment of Resistance. Use Ultimate Load Theory. Use M20/Fe415. Assure the effective cover = 37.5 mm
(5 marks) 2398

1(c) Discuss characteristic load & characteristic strength of materials.
(5 marks) 00

1(d) Explain the Types of Shear Reinforcement. Draw neat sketches.
(5 marks) 00

1(e) Write a note on design of columns subjected to Compression & Uniaxial Bending.
(5 marks) 00

2(a) A rectangular beam, having 200 mm width & 400 mm effective depth, is reinforced with 3 bars of 16 mm diameter Fe415 steel. Find the ultimate (factor or design UDL) which the beam can safely carry over a span of 5m. Use M20 concrete.
(5 marks) 2403

2(b) A simply supported rectangular beam of 8m clear span carries a factored load of 45kN/m over the entire span. The beam is 230 mm wide & effective depth is 500 mm. It is reinforced with 6 bars of 20 mm diameter bars. Design the shear reinforcement using vertical stirrups only. The ends of the beam are not confined by the compressive reaction. Use M20 concrete & Fe415 steel. Sketch the details.
(5 marks) 2399

2(c) In a RCC member, the best way to censure adequate bond is to :

• (i) Provide minimum number of large dia bars
• (ii) Provide large number of smaller dia
• (iii) Increase the cover for reinforcement
(5 marks) 00

3(a) A rectangular beam of size 30 mm width & 500 mm effective depth is subjected to a factored moment of 200 kNm. Find the reinforcement for flexure. Use M20 concrete & Fe415 steel.
(5 marks) 3296

3(b) Find the Limiting Moment of Resistance & Limiting Area of Steel for a T-beam, having flange width of 1600 mm, effective depth of 350 mm & flange thickness of 100 mm. The web width is 250 mm. Use M20 concrete & Fe500 steel.
(5 marks) 2543

3(c) In Limit State Design of RCC, deflection is computed by using

• (i) Initial tangent modulus
• (ii) Secant modulus
• (iii) Tangent modulus
• (iv) Short term & long term values of-young's modulus
(5 marks) 00

4(a) Design a short square column to cany a safe axial load of 1600kN. It is 4m long, effectively held in position & restrained against rotation at both ends (effective length 0.65L). Use M20 concrete & Fe415 steel. Show the steel details on sketches. Cany out the check for minimum eccentricity.
(5 marks) 2560

4(b) A simply supported one-way slab of a public building has a clear span of2.5 m & is supported on 9 beams 230 mm wide. Design the slab if Live Load is 5 kN/m. Use M20 concrete & Fe415 steel. Show reinforcement details. Cany out check for shear. Other checks are not needed.
(5 marks) 00

4(c) In Limit State Design of Concrete Structures, strain distribution is assumed to be:

• (i) Linear
• (ii) Non-linear
• (iii) Parabolic
• (iv) Parabolic & rectangular
(5 marks) 00

5(a) A rectangular beam section is (300 mm x 600 mm) overall. Concrete is M20 & steel is Fe415. Factored moment is 116 kNm, factored torsion is 46kNm & factored shear is 95kN. Find the reinforcement required. Sketch the details.
(5 marks) 3306

5(b) Design a slab for a room of a building, whose clear dimensions are (4 m x 5 m)' is supported on walls of width 300 mm. The Live Load = 4 kN/m2 & Floor Finish = 1 kN/m2. Use M20 Concrete & Fe415 steel. Corners of the slab are not held down. Sketch reinforcement details. Serviceability checks are not needed
(5 marks) 2549

5(c) Limit State of Serviceability for deflection including the effects due to creep shrinkage & temperature occurring alter erection of partitions & application of finishes as applicable to floors & roofs, is restricted to. (i) Span/150 (ii) Span/200 (iii) Span/250 (iv) Span/350
(5 marks) 00

6(a) Design a square footing of uniform thickness for an axially added column of (450mm x 450 mm) size. The SBC of soil= 190kN/m2 Column carries a load of Use M20 concrete & Fe415 steel. Sketch the steel details.
(5 marks) 2569

6(b) Draw the laboratory Stress-Strain curves & Idealized Stress Strain curves (asperIS456:2000) for the Concrete & the steel. Explain the same.

Table: Design Shear Strength of Concrete

100 A/bd $\le$ 0.15 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.5 & above
$\tau_c$ (MPa) for M20 concrete 0.28 0.36 0.48 0.56 0.62 0.67 0.72 0.75 0.79 0.81 0.82

Table: Values of (k) for Solid Slab

Overall Slab Depth (mm) $\ge$ 300 275 250 225 200 175 $\le$ 150
(k) 1.00 1.05 1.10 1.15 1.20 1.25 1.30

Table: Stress in compression steel, fsc(MPa) in Doubly Reinforced Beams

fy(MPa) (d'/d) - - -
- 0.05 0.1 0.15 0.20
415 355 353 342 329

Table: Bending Moment Coefficients for Slabs Spanning in 2 Directions at Right Angles, Simply Supported on Four Sides

(5 marks) 00