MU Civil Engineering (Semester 7)

Limit State Method for Reinforced Concrete Structures

December 2015

Limit State Method for Reinforced Concrete Structures

December 2015

Attempt any Four:

1 (a)
What is Bond? How can we increase the bond between steel and concrete?

5 M

1 (b)
State the assumptions made in the Limit State of Collapse (flexure) in RCC. Also draw strain and stress diagram across the section.

5 M

1 (c)
What are the functions of distribution steel in one way slab?

5 M

1 (d)
What are the steps for the design of a column subjected to axial load and biaxial bending?

5 M

1 (e)
Write are the steps for the design of a column subjected to axial load and biaxial bending?

5 M

1 (f)
What is combined footing? Sketch plan and elevation of any two types of combined footing.

5 M

Attempt the following:

2 (a)
Determine the limiting moment of resistance of the beam having dimensions 300mmX550mm (effective), is reinforced with 4-20mm diameter bars in tension zone. Use

(i) M

(ii) M

(i) M

_{20}concrete and Fe_{415}steel.(ii) M

_{20}concrete and Fe_{250}steel.
10 M

2 (b)
A beam of size 300 × 550 mm overall, is subjected to a factored bending moment of 260 kNm. Compute the reinforcement required at an effective cover of 50 mm to compression and tension reinforcement. Use M 20 concrete and Fe 415 steel.

d^{3}/d |
0.05 | 0.100 | 0.15 | 0.20 |

fx (MPa) |
355 | 353 | 342 | 329 |

10 M

Attempt the following:

3 (a)
A reinforced concrete beam of 300×550 mm overall is reinforced with 6 bars of 20 mm ϕ HYSD steel of grade Fe 415, placed at effective cover of 50 mm. The beam carries a factored UDL of 120 kN/m over a simply supported clear span of 5 m. Design the shear reinforcement if two bars are bent up at support making an angle of 45□. Use M 20 and Fe 415. Also sketch the shear reinforcement details.

pt% |
0.50 | 0.75 | 1.0 | 1.25 | 1.5 | 1.75 |

τ_{c} MPa |
0.48 | 0.56 | 0.62 | 0.67 | 0.72 | 0.75 |

10 M

3 (b)
A tee beam having 1250 mm effective width of flange has a thickness of flange equal to 115 mm. The effective depth of the beam is 550 mm and width of the web is 300mm. It is reinforced with 8 bars of 20 mm ϕ on the tension side. Determine limiting moment of resistance if M20 concrete and Fe 415 steel is used.

10 M

Attempt the following:

4 (a)
A short RCC column is subjected to a factored load of 1900 kN within the limit of minimum eccentricity. Design the column and show reinforcement details. Use M 30 and Fe 415.

6 M

4 (b)
A hall of a residential building measures 4.2 m × 6m. It is supported by 230 mm thick wall on all four sides. Design the simply supported slab using M 20 and HYSD Fe 415 steel. Assume the live load on the slab as 3kN/m

^{2}and the floor finish load as 1kN/m^{2}. Apply checks for shear, deflection and development length. Sketch the reinforcement details along both spans.
Ly/Lx |
1.3 | 1.4 | 1.5 | 1.75 |

α_{x} |
0.093 | 0.099 | 0.104 | 0.113 |

α_{y} |
0.055 | 0.051 | 0.046 | 0.037 |

14 M

Attempt the following:

5 (a)
Write step by step procedure to desing isolated footing of uniform thickness.

4 M

5 (b)
A rectangular beam of size 250 × 400 mm overall is reinforced with 3 bars of 16 mm φ as tension reinforcement. It is subjected to a shear force of 18 kN and a bending moment of 18 kN m. In addition to this it also carries a torsional moment of 1.8 kN m. Design the beam for combined BM, SF and TM.

8 M

5 (c)
A simply supported one way slab over a passage of a public building has a clear span of 2.5 m. It is supported on 230 mm thick wall. Design the slab using M20 and Fe 415 steel. Assume live load as 5 kN/m

^{2}and floor finish load as 0.75 kN/m^{2}. Apply all required checks. Sketch the reinforcement details.
8 M

6
Design the combined footing for two columns C1 and C2 of size 500 × 500 mm each, spaced at 4 m apart, carrying an axial compressive load of 1500 kN on each column. The available width restriction is 2.2m. The SBC of the soil is 150 kN/m

^{2}. Use M 25 and Fe 415. Sketch reinforcement details.
20 M

More question papers from Limit State Method for Reinforced Concrete Structures