Concrete Construction – Location of vertical construction joints at minimum shear Vertical construction joints should be located where shearing forces are a minimum in which of the following structural members?

Introduction / Context:
Construction joints are unavoidable in concrete work. To maintain structural integrity, joints are placed where their effect on strength and service behaviour is least. A general rule is to locate vertical joints at regions of minimum shear, and, where practical, where flexural demand is not at its peak.

Given Data / Assumptions:

• Members considered: slabs, beams, and girders.
• Joints are vertical planes introduced between pours.
• Simply supported spans are assumed for typical guidance.

Concept / Approach:
Shear is highest near supports and lowest near midspan in simply supported members. Thus, placing vertical joints near midspan reduces the risk of shear failure at the joint. Detailing must still ensure proper surface preparation, shear keys (if required), and dowels.

Step-by-Step Solution:
For slabs: provide joints near midspan along short direction where shear is low.For beams/girders: avoid supports; select regions closer to midspan, consistent with construction sequences and formwork.Conclude the rule applies to all listed members.

Verification / Alternative check:
Many specifications explicitly recommend locating joints at positions of minimum shear and, where possible, near points of contraflexure in continuous members.

Why Other Options Are Wrong:

• Picking any one member ignores that the same principle holds across slabs, beams, and girders.
• “None of these” contradicts standard practice.

Common Pitfalls:
Placing joints too close to supports; failing to roughen and clean the joint surface; omitting bonding grout or shear connectors where specified.

Final Answer:
All of these