ST5101-Advanced Concrete Structures- UNIT1 IMPORTANT QUESTIONS

ST5101-Advanced Concrete Structures- UNIT1 IMPORTANT QUESTIONS

syllabus:-

UNIT I DESIGN PHILOSOPHY 

 Limit state design - beams, slabs and columns according to IS Codes. Calculation of deflection and crack width according to IS Code. interaction curve generation for axial force and bending 

PART –A 

1. Explain balanced, under-reinforced and over-reinforced section. 

2. Differentiate oneway and twoway slab? 

3. Explain the merits of limit state design? 

4. What are the flanged beam?Explain neat sketch. 

5. What is the use of partial safety factors? 

6. What are slender columns? 

7. Calculate the effective length of a column if its unsupported length is 4m when both ends arefixed? 8. What is meant by moment of resistance? 

9. What is the necessity of doubly reinforced section? 

10. What are the reason for cracks in structural concrete? 

11. What are reinforcements provided required in a beam to support the combined effect of shear, bending moment, torsion? 

12. List out the factors influencing the crack with reinforced concrete members? 

13. Why is additional moment considered for long columns? 

14. What is meant by cracking torque? 

15. How does shrinkage of concrete lead to deflection in reinforced concrete flexural members? 

16. What is the difference between short and long column? 

17. What is meant by balanced failure? 

18. What are the different options available to a designer with regard to control of cracking in flexural members? 

19. What is the difference between deterministic design and probabilistic design? 

20. What are the failures will occur in long column? 

PART – B 

1. A rectangular beam 200 mm wide and 400 mm deep up to the centre of reinforcement has to resist a factored moment of 40 kNm. Design the section. Use M25 concrete and Fe 500 steel.

2. Discuss the issues involved in designing for achieving control over thermal and shrinkage cracking in large RC structures. 

3. Determine the short term deflection of a simply supported beam 250 mm x 400 mm in size for the following data:

Span of the beam = 6 m 

Effective cover = 40 mm 

Area of tension steel = 3 Nos of 28 mm diameter bars 

Live load = 10 kN/m.  

4. A rectangular beam section of width 250 mm and effective depth 500 mm is subjected to an ultimate moment of 150 kNm, ultimate shear force of 60 kN and ultimate torsional moment of 20 kNm. Design the beam. 

5. Briefly discuss torsion – shear interaction of reinforced concrete beams. 

6. A rectangular simply supported beam of span 5 m in 300 x 600 mm in cross section and is reinforced with 3 bars of 20 mm on tension side at an effective cover of 50 mm. Determine the short term deflection due to an imposed working load of 25 kN/m, excluding self weight of beam. Assume grade of concrete M20 and grade of steel as Fe 500. 

7. A simply supported reinforced concrete beam of rectangular section 250mm wide by 450mm overall depth is used over an effective span of 4m. The beam is reinforced with 3 nos.20mm dia Fe415 at an effective depth of 400mm. Two hanger bars of 10mm dia are provided. The self weight together with dead load on the beam is 4kN/m and service live load is 10 KN/m. Using M20 grade concrete and Fe415 grade steel.Compute(a) Short term deflection (b)Long term deflection (c)Maximum crack width at tension face directly under bar 

8.  Design a biaxial eccentrically loaded braced rectangular column for the following data  Ultimate axial load = 2000kN  Ultimate biaxial moments = Mux=250kNm and Muy=150kNm  Unsupported length(l)=3.25m  Effective length lex=3m, ley=2.75m  Column section (b) in x-direction=400mm, D=600mm  Adopt M25 grade concrete and Fe415 grade steel 

9. Design a T- beam for the following data: bf : 750 mm bw : 300 mm Effective depth : 450 mm Thickness of flange : 90 mm Applied moment : 350 kNm. Adopt M20 concrete and Fe 415 steel. 

10. Design a short square column for the following data : lateral dimension : 500 mm, axial load : 2x106 N. Assume M20 concrete and Fe 415 steel.