2021 Fundamentals of Concrete Structures(Wuhan University) 最新满分章节测试答案

本答案对应课程为:点我自动跳转查看
本课程起止时间为:2021-02-23到2022-01-29
本篇答案更新状态:已完结

Chapter 1 Introduction Quiz 1

1、 问题:Compared with plain concrete, the bearing capacity of reinforced concrete beams is 
选项：
A:the same
B:improved a lot
C:improved a little
D:unable to be identified
答案: 【improved a lot】

2、 问题:Compared with plain concrete beams, the ability of reinforced concrete beams to resist cracking is 
选项：
A:improved a little
B:improved a lot
C:totally the same
D:None of the above
答案: 【improved a little】

3、 问题:Reinforced concrete beam is under normal service loads, and 
选项：
A:it usually works with cracks
B:once the cracks appear, the crack is passing through to the total section
C:once the cracks appear, the bonding force between the concrete and the reinforcement along the full length is lost
D:it usually does not develop cracks
答案: 【it usually works with cracks】

4、 问题:Concrete and reinforcement have similar linear temperature expansion coefficient.
选项：
A:正确
B:错误
答案: 【正确】

5、 问题:Reinforced concrete beams work with cracks under normal load.
选项：
A:正确
B:错误
答案: 【正确】

6、 问题:China’s current code for concrete Structural Design is 《Code for Design of Concrete Structures》（GB50010-2002）
选项：
A:正确
B:错误
答案: 【错误】

【作业】Chapter 1 Introduction Homework Assignment 1

1、 问题:What is a concrete structure?
评分规则: 【 Answer: the concrete structure is mainly made of concrete materials, with reinforcement, steel bones, steel tubes, pre-stressed reinforcement and various fibers as required. The formed structure includes plain concrete structure, reinforced concrete structure, steel bone concrete structure, concrete filled steel tube structure and pre-stressed concrete structure.
】

2、 问题:Taking simply supported beams as an example, illustrate the difference of mechanical properties between plain concrete and reinforced concrete?
评分规则: 【 Answer: when there is a concentrated load action in the span of simply supported plain concrete beam. The mid-span section of the beam is tensioned, and the tensile stress will reach the tensile strength of concrete under small loads, and the beam will be broken and destroyed, which is the brittle failure without obvious symptom.For reinforced concrete beams, the tensile zone with tensile reinforcement beams will crack, after cracking, the tensile force is undertaken by the steel bar, until the yielding of the steel bar, the compressive zone reaches the ultimate load with concrete failure by compression, and then member is destroyed.The mechanical characteristics of plain concrete simply supported beam are its small load bearing capacity and brittle failure. The ultimate load of reinforced concrete simply supported beam is obviously increased, the deformation capacity is obviously improved, and it is ductile failure.
】

3、 问题:What is the principle by which steel and concrete work together?
评分规则: 【 Answer: The principle that concrete and steel work together is:(1) Good bonding force is generated between reinforcement and concrete, so that the two are integrated together;(2) The linear expansion coefficient between the steel bar and concrete is almost the same, and the relative temperature deformation will not destroy the cohesive force.
】

Chapter 2 Physical and mechanical properties of concrete and reinforcements Quiz 2

1、 问题:Strength grade of concrete is determined by
选项：
A:Characteristic cubic compressive strength.
B:Average cubic compressive strength.
C:Characteristic axial compressive strength.
D:Design value of axial compressive strength.
答案: 【Characteristic cubic compressive strength.】

2、 问题:Which one of the following statements is true?
选项：
A:The measured cubic compressive strength of concrete decreases with the increasing loading rate.
B:The measured compressive strength increases with the increasing aspect ratio of prism specimen.
C:The cube specimen can better reflect the actual compression situation of concrete rather than the prism specimen. 
D:The friction between the concrete specimen and the base loading plate increases the compressive strength of the concrete.
答案: 【The friction between the concrete specimen and the base loading plate increases the compressive strength of the concrete.】

3、 问题:For the concrete of the same strength grade, the magnitude relationship between different strength is 
选项：
A:
B:
C:
D:
答案: 【】

4、 问题:The characteristic cubic compressive strength of concrete is determined by
选项：
A:
B:
C:
D:
答案: 【】

5、 问题:Under a certain long-term load, concrete would creep. In the reinforced concrete axial compressive members:
选项：
A:Creep increases the compressive stress of concrete.
B:The compressive stress of concrete and steel bar keeps unchanged.
C:Creep decreases the compressive stress of concrete and increases the compressive stress of steel bar.
D:Creep increases the compressive stress of concrete and decreases the compressive stress of steel bar.
答案: 【Creep decreases the compressive stress of concrete and increases the compressive stress of steel bar.】

6、 问题:After the hot rolled steel bar subjected to cold stretching: 
选项：
A:Tensile strength and compressive strength are improved.
B:Only tensile strength is improved.
C:Plasticity is improved and the strength does not increase much.
D:Only compressive strength is improved.
答案: 【Only tensile strength is improved.】

7、 问题:After the hot rolled steel bar subjected to cold drawing: 
选项：
A:Tensile strength and compressive strength are improved.
B:Only tensile strength is improved.
C:Plasticity is improved and the strength does not increase much.
D:Only compressive strength is improved.
答案: 【Tensile strength and compressive strength are improved.】

8、 问题:The characteristic axial compressive strength is the basic representative value of various strength indexes of concrete.
选项：
A:正确
B:错误
答案: 【错误】

9、 问题:In the state of tri-axial compression, the compressive strength of concrete increases greatly and the ductility decreases obviously.
选项：
A:正确
B:错误
答案: 【错误】

10、 问题:The elastic modulus of concrete is greater than the deformation modulus.
选项：
A:正确
B:错误
答案: 【错误】

11、 问题:For concrete specimen subjected to uniaxial compression, the stress reaches the maximum when the strain reaches the ultimate compressive strain.
选项：
A:正确
B:错误
答案: 【错误】

12、 问题:The larger the size of the cube specimen, the higher the compressive strength.
选项：
A:正确
B:错误
答案: 【错误】

【作业】Chapter 2 Physical and mechanical properties of concrete and reinforcements Homework Assignment

1、 问题:What kind of steel bar is used in reinforced concrete structures in China? What strength grades are they categorized into?
评分规则: 【
】

2、 问题:Briefly describe the test method of concrete cubic compressive strength.
评分规则: 【 After the cube specimen with 100mmside length being cured for 28 days under standard conditions (temperature 20 ± 3 ℃, relative temperature ≥ 90%), following the standard test method (loading rate 0.3~1.0N/mm2/s): the upper and lower surfaces of the specimens are not coated with lubricant and loaded continuously until the specimens are damaged. The measured compressive strength is the characteristic cubic compressive strength of concrete.
】

3、 问题:How to determine the strength grade of concrete?
评分规则: 【 The strength grade of concrete shall be determined according to the characteristic cubic compressive strength. The characteristic cubic compressive strength is the cubic compressive strength with 95% guarantee rate measured by standard method. According to the characteristic cubic compressive strength, it can be categorized into 14 grades: C15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75, C80.
】

4、 问题:Briefly describe the stress-strain relation of concrete under short-term uniaxial loading.
评分规则: 【
】

Chapter 3 Basic principles for concrete structure calculation Quiz 3

1、 问题:S and R represent the load effect and resistance on the sections of members. If the structure or component sections are in the limit state, which relationship between S and R in the following is correct? (   ).
选项：
A:R>S
B:R=S
C:R<S
D:R<=S
答案: 【R=S】

2、 问题:The design reference period is the period selected to determine the variable loads and time-related material properties. The statistical parameters of loads considered in the "Uniform Standard for Reliability Design of Building Structures" are determined based on (    ).
选项：
A:25 years
B:50 years
C:C. 100 years
D:D. 75 years    
答案: 【50 years】

3、 问题:Which of the following states should be checked as the normal service limit state. (    )
选项：