Anna University Chennai 2007 Bachelor of Architecture AR331- DESIGN OF STRUCTURES - 11 - Question Paper

B. ARCH. DEGREE exam
FIFTH SEMESTER
AR331 - DESIGN OF STRUCTURES –II

Time: three hrs. Maximum: 100 Marks.

Yield stress for Fe 415 grade reinforcement is 415 N/mm2 and for working stress method permissible tensile stress in reinforcement is 0.55 times the yield stress and permissible compressive stress in bending is one- 3rd of the characteristic compressive strength of concrete. For the limit state of strength a load factor of 1.5 shall be used.

PART- A (10 x two = 20 marks)
ans all ques.

1. describe the characteristic strength of materials and characteristic loads.

2. elaborate the various grades of concrete and reinforcement bars recommended for reinforced concrete structural members?

3. elaborate the assumptions made in the working stress method of analysis of reinforced concrete members?

4. Determine the ratio ranging from the depth of neutral axis and the effective depth of reinforced concrete rectangular beams with Fe 415 grade tensile reinforcement for balanced parts.

5. elaborate the partial safety factors for strength of concrete and reinforcement bars?

6. Determine the limiting value of the ratio ranging from the neutral axis depth and the effective depth of reinforced concrete beams with Fe 415 grade tensile bars for limit state of collapse.

7. elaborate the maximum and minimum percentages of tensile reinforcement recommended for reinforced concrete beams?

8. elaborate the factors governing the permissible shear stress in concrete and what is the distance of critical part for the design of shear reinforcement in beams generally carrying uniformly distributed load.

9. elaborate the span to effective depth ratios recommended for cantilever slabs, simply supported and continuous slabs to satisfy their approximate stiffness?

10. elaborate the minimum percentage and maximum spacing recommended for non-structural reinforcement for temperature and shrinkage and structural tensile reinforcement in reinforced concrete slabs.

PART - B (5 x 16 = 80 marks)

11. For the limit state strength design of a single reinforced concrete part derive the formula for xu/d, and limiting moment Mu, limit in terms of pt, fy, fck, where xu, is the true depth of neutral axis, fy, and fck, are the characteristic strengths of tensile reinforcement and concrete, respectively, and pt, = As / b d, As is the area of tensile reinforcement, b and d are the width and effective depth, respectively, of the beam.

12.a) A simply supported single reinforced concrete rectangular beam of 250 m, width and 500 mm total depth with effective cover of 30 mm and effective span of six m carries uniformly distributed service load of eight kN/m in addition to self weight.
Determine the subsequent using working stress method with M 20 grade concrete and Fe 415 grade reinforcement: i) total design working load per metre, ii) Effective depth needed for balanced section, iii) Area of tensile reinforcement for balanced part.

Earning:   Approval pending.