Reinforced Concrete Column Design Flashcards
What are the two types of columns?
Braced and Unbraced
What is a braced column?
A column where the stability of the structure is provided by walls or bracing
What is an unbraced column?
A column where the lateral stability is provided by the column(s) only
Are braced columns designed to resist lateral load?
No
When is a column short?
When is a column long?
Short, slenderness < limiting value
Long, slenderness > limiting value
Where is the limiting value found?
Using a formula ‘Limiting’ from EC2
What is the slenderness ratio equal to?
Effective height / minimum cross section dimension
What is effective height?
The clear height between storeys
x
by the effective height factor from Table C13
How is the design ultimate load calculated for the floors supported by a concrete column?
Design ultimate load on floor
X
Area at each floor level
X
No. of storeys
What is the total Ultimate design load of a concrete column equal to?
Ultimate design load from floors
+
Ultimate design load from column self weight
What is Ned?
Total Ultimate Load (floors + self-weight)
What is condition 1 for end fixity conditions?
Beams connected to the column are at least as deep as the beam in the plane considered
What is condition two in end fixity conditions?
Beans or slabs either side are shallower than overall depth of column in the plane considered, but not less than half column depth
What is condition 3 in end fixity conditions?
Column does not provide more than nominal resistance to rotation
What are the end conditions used for?
Obtaining an effective height factor from table C13
