it is a set f objective questions on reinforced cement concrete prepared by our skilled teachers and students. it will help students excel in their ci...
1. In reinforced cement concrete structures, the steel reinforcement consists of a) Deformed bars b) Cold twisted bars c) Mild steel and medium tensile steel bars d) All of these 2. The compressive strength of concrete is about 10 – 15% of its tensile strength. a) True b) False 3. In singly reinforced beams, steel reinforcement is provided in a) Tensile zone b) Compressive zone c) Both tensile and compressive zones d) Neutral zone 4. In a simply supported reinforced concrete beam, the reinforcement is placed a) Below the neutral axis b) Above the neutral axis c) At the neutral axis. d) Any one of these. 5. In a singly reinforced beam, the effective depth is measured from the compression edge to the a) Tensile edge b) Centre of tensile reinforcement c) Neutral axis of the beam d) None of these 6. Analysis of reinforced concrete can be done by a) Straight line theory b) Elastic theory c) Ultimate load theory d) All of these 7. The application of elastic theory to the beams is based on the assumption that a) At any cross section, plane sections before bending remain plane after bending b) All the tensile stresses are taken up by reinforcement alone and none by the concrete c) Steel reinforcement is free from initial stresses when it is embedded in concrete. d) All of the above. 8. When a load on the reinforced concrete beam is small so that the tensile stress set up in the concrete below the neutral axis is smaller than the permissible, then the concrete area_______ the neutral axis will not crack. a) Above b) Below 9. In a singly reinforced concrete beam, if the load is very small a) Only concrete will resist tension b) Only steel bars will resist tension c) Both concrete and steel will resist tension d) Both concrete and steel will resist compression. 10. The modular ratio is the ratio of a) Young’s modulus of the steel to the young’s modulus of concrete b) Young’s modulus of the concrete to the young’s modulus of steel c) Load carried by steel to the load carried by concrete d) Load carried by concrete to the load carried by steel.
11. In a reinforced concrete column, the cross sectional area of the steel bar is As and that of concrete is Ac. The equivalent area of the section in terms of concrete is equal to a) As +m Ac b) Ac +m As c) As - m Ac d) Ac - m As 12. In a singly reinforced concrete beam, as the load increases a) Only concrete will resist tension b) Only steel will resist tension c) Both concrete and steel will resist tension d) Both concrete and steel will resist compression. 13. In a singly reinforced beam, the effective depth is measured from its compression edge to a) Tensile edge b) Tensile reinforcement c) Neutral axis of beam d) Longitudinal central axis 14. The section of a reinforced beam where most distant concrete fiber in compression and tension in steel attains permissible stresses simultaneously is called a) Balanced section b) Economic section c) Critical section d) All the above 15. In a singly reinforced beam if the permissible stresses in concrete reach earlier than that in steel, the beam section is called a) Under reinforced section b) Over reinforced section c) Economic section d) Critical section 16. As the percentage of steel increases a) Depth of neutral axis decreases b) Depth of neutral axis increases c) Lever arm increases d) Lever arm decreases e) None of these 17. According to I.S:456 specifications, the safe diagonal tensile stress for M150 grade concrete is a) 5kg/cm2 b) 10kg/cm2 c) 15kg/cm2 d) 20kg/cm2 e) 25kg/cm2 18. If the span to depth ratio of simply supported beam up to 10m length is not greater than 20, the vertical deflection remains within satisfactory limit. a) True b) False 19. If xu is the depth of neutral axis, then the center of compressive strength in the design stress block is
a) 0.36xu b) 0.42xu c) 0.48xu 20. Calculate the percentage of steel in a 40cmx80cm reinforced beam with 3 bars of 25mm diameter. a) 0.42 b) 0.36 c) 0.48 d) 0.52 21. A plain concrete beam fails when loaded, fails if the stress on tension side reaches the tensile strength of the concrete. a) True b) False 22. In under reinforced section the depth of neutral axis xu will be ________ than the maximum value xu max a) smaller b) greater 23. Under normal loading conditions the tensile stresses set up in the concrete will be _____the permissible stresses. a) more than b) Less than c) Equal to 24. A reinforced concrete beam will crack if tensile stresses set up in the concrete below the neutral axis are a) less than the permissible stress b) More than the permissible stress c) Equal to the permissible stress d) Any one of these 25. The moment of resistance of an under reinforced section is computed on the basis of a) Compression force developed in concrete b) Tensile force developed in steel c) Both a & b d) None of these 26. For an over reinforced (singly reinforced) rectangular reinforced concrete section a) The lever arm will be less than that for a balanced section b) The maximum stress developed by steel will be equal to the allowable stress in steel c) The maximum stress developed by concrete will be equal to allowable stress in concrete d) None of the above 27. The moment of resistance of an over reinforced section is determined on the basis of a) Tensile force developed in steel b) Compressive force developed in concrete c) Both a&b d) None of these 28. The neutral axis of an over reinforced section falls a) On the critical neutral axis balanced section b) Below the critical neutral axis of balanced section
c) Above the critical neutral axis of balanced section d) None of the above 29. For a balanced section, the moment of resistance obtained from compressive force will be _____ the moment of resistance obtained from the tensile force. a) Greater than b) Less than c) Equal to 30. The effective depth of a singly reinforced rectangular beam is 300mm. the section is over reinforced and the neutral axis is 120mm below the top. If the maximum stress attained by concrete is 5N/mm 2 and modular ratio is18, then the stress developed in the steel will be a) 130N/mm2 b) 135 N/mm2 c) 160 N/mm2 d) 180N/mm2 31. If modular ratio is m, effective depth is d and stress ratio is r= σst/σcb then the depth of neutral axis (nc) of a balanced section is a) m/(m-r) *d b) m/(m+r)*d c) (m+r)/m*d d) (m/r)*d 32. Examine the following statements: i. Factor of safety for steel should be based on its yield stress. ii. Factor of safety for steel should be based on its ultimate stress. iii. Factor of safety for concrete should be based on its yield stress. iv. Factor of safety for concrete should be based on its ultimate stress. The correct statements are: a) i and iii b) i and iv c) ii and iii d) ii and iv 33. The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone. a) Compressive stress b) Shear stress c) Bond stress d) Tensile stress 34. The purpose of reinforcement in prestressed concrete is a) To provide adequate bond stress b) To resist tensile stresses c) To impart initial compressive stress in concrete d) All the above 35. The bond strength between steel reinforcement and concrete is affected by i. Steel properties ii. Concrete properties iii. Shrinkage of concrete a) i and ii
b) ii and iii c) i and iii d) i ii and iii 36. Mult of singly reinforced balanced RC rectangular beam section is. a) 0.115fck bd2 b) 0.135fckbd2 c) 0.185fck bd2 d) 0.225fck bd2 37. Consider the following statements: The reinforcement in reinforced concrete shall have concrete cover, the thickness of such cover shall be not less than 1.25mm 2. Diameter of bar 3. Spacing between bars 4.5mm Which of the statements are correct? a) 3&4 b) 1&4 c) 2&3 d) 1&2 38. Which one of the following statements is correct? Doubly reinforced beams are recommended when a) The depth of beam is restricted b) The breadth of beam is restricted c) Both breadth and depth are restricted d) Shear is high 39. In the limit state design method of concrete structures, the recommended partial material safety factor ϒm for steel according to IS 456-2000 is a) 1.5 b) 1.15 c) 1 d) 0.87 40. A simply supported rectangular beam of span 20m is subjected to udl. The minimum effective depth required to check deflection of this beam, when modification factor for tension and compression are 0.9 and 1.1 respectively will be a) 2m b) 1.8m c) 1.3m d) 1.0m 41. Minimum tension steel in RC beam needs to be provided to a) Prevent sudden failure b) Arrest crack width c) Control excessive deflection d) Prevent surface hair cracks 42. In the limit state design method a) It ensures adequate safety of structure against collapse b) Actual stresses developed at collapse differ considerably from the theoretical values.
c) Both a & b d) None of these 43. Which one of the following sections performs better on the ductility criterion? a) Balanced section b) Over reinforced section c) Under reinforced section d) Non prismatic section 44. In a doubly reinforced rectangular beam the allowable stress in compression steel is a) Equal to permissible stress in tension in steel b) More than the permissible stress in tension in steel c) Less than the permissible stress in tension in steel d) Not related to the permissible concrete compression stress 45. Effective depth of a singly reinforced rectangular beam is30cm. The section is over reinforced and the neutral axis is 12cm below the top. If the maximum stress attained by concrete is 50kg/cm2 and modular ratio is 18, then stress developed in steel would be a) 1800kg/cm2 b) 1600kg/cm2 c) 1350 kg/cm2 d) 1300kg/cm2 46. Percentage of tensile steel required to produce a balanced reinforced concrete section a) Reduces as the yield strength of steel increases b) Remains unchanged irrespective of the yield. c) Is only a function of the modulus of elasticity of steel . 47. For a given grade of steel limiting reinforcement index for a singly reinforced beam is proportional to a) fck b) fy c) fy/fck d) fck/fy 48. Bond strength between steel and concrete is due to a) Friction b) Adhesion c) Both a&b d) None of these 49. For a reinforced concrete section the shape of shear stress diagram is a) Wholly parabolic b) Wholly rectangular c) Parabolic above neutral axis & rectangular below neutral axis d) rectangular above neutral axis & parabolic below neutral axis 50. The load obtained by multiplying a characteristic load by an appropriate partial safety factor is called Factored Load.
