ST5101-Advanced Concrete Structures- UNIT2 IMPORTANT QUESTIONS

ST5101-Advanced Concrete Structures- UNIT2 IMPORTANT QUESTIONS

syllabus:-

UNIT II DESIGN OF SPECIAL RC ELEMENTS 

Design of slender columns - Design of RC walls. Strut and tie method of analysis for corbels and deep beams , Design of corbels, Deep-beams and grid floors.

 PART – A 

1. State the advantages of flat slabs.
2. What is meant by punching shear?
3. What are the modes of failure of deep beams?
4. Give any two characteristics of yield line.
5. What do you meant by coupled shear walls?
6. What is the main difference between a braced wall and an unbraced wall?
7. Why side face reinforcements are extremely important in deep beams?
8. Explain the arch action on the deep beam with the load transfer model?
9. What is a corbel? Explain with a neat diagram?
10. How do you calculate the lever arm for a deep beam?
11. What is a bracket? Where it is used?
12. Define shear wall.
13. Explain grid or coffered floor systems, with a neat sketch.
14. How a nib is different from cantilever? Draw a neat sketch.
15. What is the development length adopted for deep bemas? Calculate it for 16 mm mild bars in M20 grade concrete.
16. Explain the strut and tie method of analysis for a corbel, with the equation of lever arm (z/d).
17. What are the advantages of a flat slab over ordinary slab?
18. Explain the term drop and capital in flat slab.
19. What is a flat plate?
20. Explain the characteristic features of yield lines?

PART B 

1. Design a corbel for a 350mm square column to support an ultimate vertical load of 600kN with its Line of action 200mm from the face of the column. Use M20 grade concrete and Fe 415 grade steel.

2. Design a simply supported deep beam with width = 250mm, overall depth (D) = 3500mm, width
Of supports = 500mm, clear span = 5m.Live load on the beam = 150kN/m at service state. Adopt
M20 grade concrete and Fe415 steel.

3. R.C. grid floor is to be designed to cover a floor area of 12mx18m.The spacing of ribs in mutually
Perpendicular directions is 1.5mc/c. Live load on the floor is 2kN/m. Analyse the grid floor by IS-
456 methods and design the suitable reinforcements with grid floor.

4.    Design a single span deep beam with following data.
      a) Effective span =6m
      b) Over all depth=6m
      c) Width of support=0.6m
      d)width of beam =0.4m
    Total load on beam including self-weight 400kn/m .Use M20&Fe415.
5. Design a column of size 450 x 300 mm using M30 concrete and Fe 500 steel. Given lex = 6.0 m, ler = 5.5 m, Pu = 1500 kN, Mux = 45 kN-m at top and 30 kNm at bottom Mny = 40 kNm at top and 25 kNm at bottom. The column is bent in double curvature and assume a cover of 50 mm.

6. A plain traced concrete wall of dimensions 8 m high, 6 m long and 200 mm thick is restrained against rotation at its base and unrestrained at the ends. If it has to carry a factored total gravity load of 200 kN and a factored horizontal load of 8 kN at top. Check the safety of the wall. Assume fck = 25, fy = 500.

7. What is meant by shear wall? Write the step by step procedure for the design of rectangular shear wall with boundary element.

8. Design a RC corbel to carry load of 350 kN acting at a distance of 250 mm from the face to face of a column of size 300 x 450 mm. the corbel is provided on the 300 mm face, sketch the reinforcement details.

9. Explain the basis for the simplified code procedure for analyzing the design strength components of a biaxially loaded column with rectangular section.

10. Design the longitudinal reinforcement for a braced column, 300 mm x 500 mm, subject to a factored axial load of 1500 kN and factored moments of 70 kNm and 50 kNm with respect to the major axis and minor axis respectively at the top end. Assume that the column is bent in double curvature (in both directions) with the moments at the bottom end equal to 50 percent of the corresponding moments at top. Assume an unsupported length of 6.0 m and an effective length ratio of 0.85 in both directions. Use M30 concrete and Fe 415 steel.