Structure-IV — Summer 2018

Explain Briefly: Working state method. [4]

(i) Calculate design compressive strength of M 25 concrete (ii) Find modulus [6] of elasticity of M 25 concrete (iii) Calculate design strength of Fe 415 steel.

Q2. (b) Ashort R.C.Ccolumn of size 300mm X 400mm is reinforced with 6 bars of [10] 20mm dia. Determine the safe load column can carry if M-20 grade of concrete and Fe 250 steel is used. Also find the spacing of lateral ties and draw required sketch.

Asingly RC beam has effective dimension of 250mm X 450mm. It is [5] reinforced with 3-20mm dia. of Fe 415. Find out moment of resistance of beam. Use M20

Adoubly reinforced beam of 300mm X 600mm overall is reinforced with 4- [10] 20mm dia. bars as compression reinforcement and 6-20mm dia. bars as tensile reinforcement. Effective cover on both sides is 50mm. M-25 grade of concrete and Fe-415 grade of steel bar is used. Compute moment of resistance

Design and detail two way simply supported slab of 2.5m x 3.75m. 150 mm [10] thick slab is supported by 350 mm thick brick wall and live load on slab is 3.0 kN/sqm. Take value of αx & αy from IS 456. Take M20 and Fe 415 grade of material.

Write Difference for Balanced sections, Under reinforced section, Over [5] reinforced section.

Differentiate between one way and two way slabs [5]

Design a one way continuous slab having three equal spans of 3.5 m effective [10] with following data. (1) Imposed load = 4 kN/ m2 (2) Floor finish = 1 kN/ m2 (3) Concrete M-20 and steel Fe-250 grade. Sketch the design details

Design an isolated square pad footing for the RCC column of size 400 mm x [10] 400 mm to transmit axial load of 850 kN. The safe bearing capacity of soil is 180 kN/ m2. Use M-20 concrete and Fe-415 steel. No check for shear is required. Sketch the details

Design a slab for office room of 3.2 m x 8.5 m size. The slab is resting on 300 mm [10] thick wall and resisting live load of 2.5 kN/m2 . Use M-20 concrete mix and Fe- 415 steel. Check the slab for control of deflection. Sketch details