questions on advanced concrete
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Name: Roll No: Due 9/3/15 CE 7120 Homework 2 1. For the beam section in Figure 1: a) Develop the moment vs. curvature curve. b) Sketch the variations in the strain profiles across the depth of the section, with increasing moment. Consider an increment of 0.0005 for the strain at the compressive fibre of the section. Grade of concrete is M20 and grade of steel is Fe250. Clear cover is 30 mm and diameter of stirrups is 8 mm. Show the curves with and without the tension stiffening effect. The tension stiffening effect can be modelled as per the FIB recommendations. Use the material properties and partial safety factors as per IS 456: 2000. Neglect any confinement of concrete. 2. Develop the approximate trilinear moment vs. curvature curves, for a beam section with same dimensions and material properties as in Figure 1, but with varying amount of reinforcement at same ‘d’. Consider p t = 0.5%, 1.0%, 1.5% and p t,lim. Overlap the plots in a single graph. Neglect the tension stiffening effect. Comment on the results. Suggested steps a) Calculate M cr , Ф cr b) Calculate M y , Ф y c) Calculate M u , Ф u . d) Plot the points and join them by straight lines. 3. For the column section in Figure 2, develop the moment vs. rotation curves for the plastic hinge region near the joint, for the axial load levels of 0, 0.5P b , P b and 1.5 P b . Overlap the plots in a single graph. The axial load due to gravity, that will cause balanced failure under increasing moment due to lateral load, is denoted as P b . Grade of concrete is M35 and grade of steel is Fe415. Use the material properties and partial safety factors as per IS 456: 2000. Neglect any confinement of concrete. All dimensions are in mm. (3) 16 Ø 150 Figure 1 300 400 400 (8) 25 Ø Figure 2 60
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questions from advanced concrete
Transcript of questions on advanced concrete
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Name: Roll No:
Due 9/3/15
CE 7120 Homework 2 1. For the beam section in Figure 1: a) Develop the moment vs. curvature curve. b) Sketch the variations in the strain profiles across the depth of the section, with increasing moment. Consider an increment of 0.0005 for the strain at the compressive fibre of the section. Grade of concrete is M20 and grade of steel is Fe250. Clear cover is 30 mm and diameter of stirrups is 8 mm. Show the curves with and without the tension stiffening effect. The tension stiffening effect can be modelled as per the FIB recommendations. Use the material properties and partial safety factors as per IS 456: 2000. Neglect any confinement of concrete. 2. Develop the approximate trilinear moment vs. curvature curves, for a beam section with same dimensions and material properties as in Figure 1, but with varying amount of reinforcement at same d. Consider pt = 0.5%, 1.0%, 1.5% and pt,lim. Overlap the plots in a single graph. Neglect the tension stiffening effect. Comment on the results. Suggested steps
a) Calculate Mcr, cr b) Calculate My, y c) Calculate Mu, u. d) Plot the points and join them by straight lines.
3. For the column section in Figure 2, develop the moment vs. rotation curves for the plastic hinge region near the joint, for the axial load levels of 0, 0.5Pb, Pb and 1.5 Pb. Overlap the plots in a single graph. The axial load due to gravity, that will cause balanced failure under increasing moment due to lateral load, is denoted as Pb. Grade of concrete is M35 and grade of steel is Fe415. Use the material properties and partial safety factors as per IS 456: 2000. Neglect any confinement of concrete.
All dimensions are in mm.
(3) 16
150
Figure 1
300
400
400 (8) 25
Figure 2
60
