1 (a)
A short column 300mm × 300mm is reinforced with 4 bars of 20mm diameter. Determine the safe working load on the column. Use M20 grade of concrete and Fe415 grade of steel.
5 M
1 (b)
Derive the expression for balanced moment of resistance for a singly reinforced rectangle section.
5 M
1 (c)
Name different methods of post-tensioning. Discuss any one method in details.
5 M
1 (d)
Why is necessary of using high strength concrete and high steel in prestressed concrete.
5 M
2 (a)
Design a simply supported beam subjected to u.d.l of 40 kN/m. The width of the beam is bars of 16 mm diameter in compression and 4 bars of 16 mm dia. In tension. Determine Moment of resistance of the section. Use M20 grade of concrete and Fe415 grade of steel.
10 M
3 (a)
A Reinforced concrete Tee beam has the following dimension:
Flange width 1000 mm
Width of Rib 230 mm
Depth of Rib 400 mm
Depth Of flange 120 mm
Steel provided 4 no of 20mm diameter bars.
span 8.0 meter
Grade of concrete M20 and Steel Fe415
Find the safe UDL the beam can carry.
Flange width 1000 mm
Width of Rib 230 mm
Depth of Rib 400 mm
Depth Of flange 120 mm
Steel provided 4 no of 20mm diameter bars.
span 8.0 meter
Grade of concrete M20 and Steel Fe415
Find the safe UDL the beam can carry.
10 M
3 (b)
A rectangle beam 230mm × 450mm (effective depth) is reinforced with 6 bars of 16 mm diameter out of which two bars are bent at 45°. Determine the shear resistance of bent up bars and additional shear reinforcement required if the shear force is 200 kN. Design shear reinforcement adopt M20 and Fe415.
10 M
4 (a)
A column is 400mm× 600mm is reinforced with 8 bars of 16 mm diameter it is subjected to compressive force of 450 kN. Mx=50 kNm My=40 kNm check the safety of the column as uncracked section. Use M20 grade of concrete and Fe 415 grade of steel.
10 M
4 (b)
Design a simply supported slab having dimension 4m × 6m. Assume live load of 4kN/m2 and floor finish of 1 kN/m2. Use M20 grade of concrete and Fe415 grade of steel.
αx=0.089 αy=0.056.
αx=0.089 αy=0.056.
10 M
5
Design the isolated sloped footing (rectangular) for a reinforced concrete column 230mm× 450mm carrying axial load of 1200kN. The bearing capacity of soil is 150kN/m2 . Use M20 grade of concrete and Fe415 grade of steel. Draw sketch showing reinforcement details.
20 M
6 (a)
A PSC beam 230mm×450mm is used over an effective span of 5m to support an imposed load of 4 kN/m. Determine the magnitude of prestressing force located at 60mm from the soffit of the beam at mid span, where permissible stresses in tension are limited to 1 N/mm2 at service stage consider 15% loss of stresses in steel. Cable is parabolic and concentric at support. Determine stresses in extreme fibers at services at quarter span.
14 M
6 (b)
An I-section prestressed concrete beam has top flange 1000 mm ×200mm, bottom flange 600mm×200mm and web is 200m×200mm depth. Determine the efficiency of the section.
6 M
7
A prestress concrete beam (I-section) has top flange 1400 mm × 200mm, bottom flange 700 mm × 200 mm and web 180mm × 2000 mm (depth) is prestressed with wires having area 300mm2 located at 50mm from soffit and carrying initial stress of 1200 N/mm2 the span beam is 10 m calculate the percentage loss of stress in wires if
i) beam is pretensioned
ii) the beam is post-tensioned use the following data.
Es-200 kN/mm2 and Ec=35kN/mm2 Relaxation of steel stress=5% of the initial stress.
Shrinkage of concrete =300 × 10-6 for pretensioning and 200×100-6 for post tensioning creep co-efficient=1.6 slip at anchorage =1mm frictional co-efficient for wave effect 0.0015/m. "
i) beam is pretensioned
ii) the beam is post-tensioned use the following data.
Es-200 kN/mm2 and Ec=35kN/mm2 Relaxation of steel stress=5% of the initial stress.
Shrinkage of concrete =300 × 10-6 for pretensioning and 200×100-6 for post tensioning creep co-efficient=1.6 slip at anchorage =1mm frictional co-efficient for wave effect 0.0015/m. "
20 M
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