A: ensure the simplification of the calculation diagram
B: avoid the occurrence of the over-reinforced failure
C: ensure the compressive reinforcements yield at the failure of the beam
D: ensure the tensile reinforcements yield at the failure of the beam
举一反三
- 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
- For a given [img=24x27]1803b9532cc8765.png[/img], when calculating the bearing capacity of the normal section of a doubly reinforced concrete rectangular beam, if [img=46x23]1803b95334b0ce7.png[/img], it indicates that ( ). A: the compressive reinforcements are excessively allocated B: the reinforcements in the compression zone are lightly allocated and needs to be reallocated C: The beam section is over-sized D: The concrete strength is too large
- If [img=46x23]1803b95368d5b28.png[/img], the concrete fiber strain at the edge of the compression zone at the failure of the beam satisfies the condition [img=59x19]1803b95371d436c.png[/img], and at the same time, the tensile strain of the tensile reinforcements satisfies the condition [img=53x22]1803b95379d4907.png[/img], i.e., the tensile reinforcement has yielded at the failure of the beam, and the failure mode of such beam belongs to the over-reinforced failure.
- When conducting the section analysis on the bearing capacity of the normal section of a doubly reinforced concrete rectangular beam, if [img=46x23]1803b9533db5432.png[/img], the ultimate bending moment the section undertakes can be ( ). A: calculated by approximating the relationship between [img=8x23]1803b9534526202.png[/img] and [img=14x23]1803b9534d0c9d8.png[/img] as [img=46x23]1803b953549d24e.png[/img] B: recalculated according to the case that the area of the tensile reinforcements is unknown C: recalculated according to the case that the area of the compressive reinforcements is unknown D: determined according to the minimum reinforcement ratio
- In the calculation of the bearing capacity of the normal section of a T-shaped reinforced concrete beam, it is assumed that ( ) within the effective width of the compressed flange. A: the compressive stress is uniformly distributed B: the compressive stress is distributed in a parabolic shape C: the compressive stress is distributed in a triangle shape D: the compressive stress is distributed partly uniformly and partly non-uniformly
内容
- 0
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%
- 1
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
- 2
In order to ensure the reliability of prestressed concrete axial tension members, in addition to the calculation of bearing capacity and crack control, the calculation of bearing capacity in construction stage and the local pressure of concrete at the end of post-tensioning members should also be carried out.
- 3
What are beams in reinforced concrete building? A: simply supported-beam B: built-in beam C: edge beam
- 4
Which of the following is not the reason why concrete needs reinforcement? A: Reinforcement has good tensile resistance, while concrete has good compressive resistance. B: Reinforcement has good compressive resistance as concrete. C: Engineers prefer ductile failure to brittle failure of the members. D: Reinforcement and concrete can work together to increase the bearing capacity of the members.