Rcc Most Important Questions 3-1 4m553j

Design of Reinforced Concrete Structures Most IMPORTANT : Just average 4 Questions from each Unit 1a) Distinguish between working stress method and limit state method of analysis of R.C. structures. 1b) Explain balanced, under-reinforced & over-reinforced sections as per Working Stress and Limit State Methods with sketches 2a) Sketch the stress – strain curves for Concrete, Mild steel and HYSD steel. Briefly explain them. 2b) What is Stress block as per the Limit state method? Derive the stress block parameters from first principles. *** 1a) Design flexural reinforcement for an RC beam of size 300mm wide and 500mm deep to resist an ultimate moment of 245 kNm. Assume moderate exposure condition. Use M25 concrete and Fe 500 grade steel. Adopt Limit State method. 1b) Determine the ultimate moment of resistance of the doubly reinforced beam section with the following characteristics b = 250mm d= 500mm ast = 18474 mm2 fy = 415 mpa fck = 25mpa g1 = 50mm Asc = 942 mm2 2) Design a 4 span continuous beam of equal spans of each 4.5 m. The superimposed load on the beam is 40 kN/m. Adopt M 20 concrete and Fe 415 steel. The width of the beam can be taken as 300mm. 3) The beams spaced at 4 m c/c and having simply ed span of 8.5m, the floor slab of a hall of size 16m x 8.5m is 250 mm thick and overall depth is 500 mm. Design the beam for flexure for 2 2 the following data: Live load = 4kN/m , Floor finish = 1.5kN/m , concrete grade M20, Steel grade Fe 500. Draw the longitudinal section and cross section at mid span 4) An isolated T-Beam has a flange width of 1000mm. flange thickness of 80mm and effective depth of 400mm. The rib is 240mm wide and reinforced with 5 bars of 20mm diameter. Determine the moment of resistance of the section, If M 20 concrete and Fe 415 steel are used. The beam is simply ed over a span of 4m. *** 1) Design a simply ed slab to cover a room with internal dimensions 4.0 m x 5.0 m and 230 mm thick brick walls aal around. Assume a live load of 5kN/m2 and a finish load of 1 kn/m2 . use m 20 concrete and Fe 415 steel. Assume thet the slab comers are free to lift up. Assume mild exposure conditions. Draw a suitable scale plan, cross section along both sides 2) Design a reinforced concrete slab for a room of size 5.5m x 4m clear in size if the super imposed load 2 is 5 kN/m . Use M 20 concrete and Fe 415 steel. The edges are simply ed and corners are held down. 3) Design a slab for a Two room masonry building with internal dimensions of each room as 4.00m x 5.00m with one long edge continuous. the masonry walls are of 300 mm thick. Assume a live load of 3.0kN/m2 and a finish load of 1.5kN/m2 and a finish load of .5kN/m2 Assume that the slab corners are not free to lift up. Consider M25 Concrete and Fe415Steel. 4) Design a reinforced concrete slab of size 6m x 4m whose one short edge is discontinuous and 2 corners are retained at s. The slab has to carry a live load of 3kN/m and a floor finish of 1 2 kN/m . Use M 20 concrete and Fe 415 steel. Sketch the details of reinforcements. *** 1) Design an isolated footing for a column with an axial force of 2500 kN under working loads. The size of the column is 500mm x 500mm. consider S.B.C of soil as 250 kN/m 2. Consider m25 Concrete and Fe500 steel. Assume mild exposure condition. 2) Design an isolated footing for a column with an axial force of 2500 kN under working loads. The size of the column is 450 mm x 600 mm . Consider S.B.C. of soil as 300kN/m 2. Consider M25 concrete and Fe415 steel.

3) Design a rectangular isolated sloped footing for a column of size 360 mm × 660 mm carrying an 2 axial load of 2500 kN. The S.B.C. of the soil is 280 kN / m . Use M 30 grade concrete and Fe 500 grade steel. Sketch the reinforcement details. Assume moderate exposure condition. [15] ***

1) Do notes problem number 1 for axially loaded Columns 2) Design a short square column, with effective length 3.5 m, capable of safely resisting factored load p u = 2000 kN 7 M u = 125 kN-m (under unaixial eccentricity the column is braced against side sway) Use M25 Concrete and Fe 415 Steel 3) Design the reinforcement in the column of size 400mm x 600mm subject to a factored axial load of 3000KN and Moment about major axis Mux = 2oo KN-m the column has an uned length of 3.2 m and is braced againset side way in both directions. Use M25 concrete and Fe415 steel. 4) Design the reinforcement for a column having a cross-section of 300 × 520 mm and effective length of 3.6 m subjected to a factored axial load 1280 kN with biaxial moments of 200 kNm and 120 kNm with respect to major and minor axes respectively. Use M30 concrete and Fe 415 steel. Sketch the reinforcement details. Assume moderate exposure condition. [15]. 5) An unbraced column 200mm square is subjected to the following factored loads P=3200 kN; at the top Mx = 76 kN-m and My = 68kN-m: at the bottom Mx = 38 kN-m and My = 34 kN-m; lo = 5m; le = 6.0m; at bottom the axes, use M 30 and Fe415 steel Design the longitudinal steel. 6) R.C. column 300mm x 500mm, reinforced with 8 bars of 20 mm dia., uniformly distributed on all the faces is braced against side way and has uned length of 7m. Taking effective length ratio equal to 0.85 in both the directions, determine the maximum factored axial load carrying capacity of the column. Use M 20 concrete and Fe 415 steel 7) Design a short helically reinforced column of uned length 3.6 m to carry an axial service load of 1200 kN. Use M 30 concrete and Fe 415 grade steel. Sketch the reinforcement details. Assume moderate exposure condition. [15] *** 1) Design a dog-legged stair in a public building in which the floor height is 3.4m. the stair case room measures. 3.0 m x 4.5 m. the live load may be taken as 3.0 kN/m 2. use M20 concrete and Fe 415 Steel 2) The clear dimensions of a staircase hall are 28 m × 4.4 m. The floor to floor height is 3.6 m. The landing slabs span in the same direction as the stair and are ed by the walls at the ends. The stair is used in a residential building. Design a dog-legged staircase. Use M 30 concrete and Fe 500 steel. Sketch the reinforcement details. Sketch the reinforcement details. Assume moderate exposure condition. [15] ***