• 2022-05-31
    In the calculation of the bearing capacity of the normal section of a doubly reinforced concrete rectangular beam, if [img=63x27]1803b9532781df8.png[/img], it indicates that ( ).
    A: the compressive reinforcements will not yield
    B: the tensile reinforcements will not yield
    C: the section is over-sized
    D: the compressive reinforcements have already yielded when the failure of the beam occurs
  • A

    举一反三

    内容

    • 0

      The main reason why spiral stirrups can improve the bearing capacity of the normal section of axial compressed columns is that ( ). A: the strength of spiral stirrups is high B: spiral stirrups can effectively restrain the longitudinal reinforcements and improve the compressive strength of longitudinal reinforcements C: spiral stirrups can effectively restrain the core concrete and improve its compressive strength D: spiral stirrups have strong deformation capacity

    • 1

      A reinforced concrete rectangular beam of C40 grade concrete is reinforced with HRB400 grade steel bars in tension. Given that [img=14x23]17de816843b92c0.png[/img] is 1.71[img=62x27]17de81684ecebb0.png[/img] and fy is 360[img=62x27]17de81684ecebb0.png[/img] the minimum reinforcement ratio of longitudinal tensile reinforcements should be ( ). A: 0.18% B: 0.19% C: 0.20% D: 0.21%

    • 2

      The most effective measure to avoid the inclined compression failure for a beam is by ( ). A: increasing the amount of stirrups B: increasing the section size C: increasing the amount of web reinforcements D: increasing the amount of bent-up reinforcements

    • 3

      The cross section of a straight beam remains plane when the beam deforms due to bending. This causes ( ) on one side of the beam and ( ) on the other side. The neutral axis is subjected to ( ) .? normal stress; shear stress; zero stress|tensile stress; compressive stress; zero stress|compressive stress; tensile stress; maximum normal stress|shear stress; normal stress; zero stress

    • 4

      For fully prestressed concrete under the service load, in the section of concrete member A: Tensile stress is allowed to occur B: No tensile stress occurs C: Allow for cracks D: There is no compressive stress