Chapter 4

Question 1

Briefly describe the Simplified Method

Answer 1

assumption that plane sections remain plane
Max axial stress is 50MPa
uses longitudinal reinforcement for flexure and axial loads
uses transverse reinforcement for shear

Question 2

Briefly describe the General Method

Answer 2

assumption that plane sections remain plane

designs for flexure, shear, torsion and axial load

Question 3

List factors that influence modes of shear failure

Answer 3

• span to depth ratio
• section dimensions
• thickness of web
• tensile strength of concrete
• reinforcement ratio
• fy
• cc

Question 4

What are the 3 modes of shear failure

Answer 4

1) flexural failure
2) shear tension failure (not enough reinforcement)
3) shear compression failure (too much reinforcement)

Question 5

List the 4 positive attributes of shear reinforcement

Answer 5

1) increases the concrete strength by confining the concrete
2) restrains the longitudinal reinforcement from displacing laterally
3) provides vertical support for concrete between cracks - creates an arching action
4) induces dowel action in reinforcement at cracks.