Reinforced Concrete Beam Design Flashcards
What is Fck?
Compressive strength of concrete (cylinder)
What is Fyk?
Characteristic yield strength of reinforcement
What is b?
Breadth of beam
What is h?
Overall depth of beam
What is d?
Effective depth of beam
What is effective depth?
Depth to centroid of tension reinforcement
What is As?
Area of tension steel
What is the partial factor of safety for dead loads?
1.35
What is the partial factor of safety for live loads?
1.50
How is design load per metre of a beam calculated?
(1.35 x Total dead Load/m) + (1.50 x Total live load/m)
What is total dead load?
The characteristic dead load + beams self weight
How is maximum shear force calculated?
Design ultimate load and effective span are used within the shear force equation
How is maximum bending moment calculated?
Ultimate design load and effective span are used in the bending moment calculation
What is effective span?
The smaller value between:
Distance between CL of supports
And
Clear span + Total depth
What is step one in calculating longitudinal reinforcement?
Calculate k factor
What value must k not exceed?
0.167
What is step 2 in calculating the area of longitudinal reinforcement?
Find z/d
What is step 3 in calculating longitudinal reinforcement?
Find Z
Z = d x (z/d)
What is step 4 in calculating longitudinal reinforcement?
Find As
What is step 5 in calculating longitudinal reinforcement?
Check As exceeds min percentage required
What is step 6 in calculating longitudinal reinforcement?
Choose reinforcing bars that give a reinforcement of at least As
What table is used to determine longitudinal reinforcement (main bar)?
Table C5 of EC2
What Eurocode is used for reinforced concrete?
EC2
What is effective depth = to?
Total depth - min cover - shear link dia. - (half main bar dia.)
How is cover found?
Using table C1 and the duration of fire resistance, the value of ‘min axis distance from soffit’ = cover
How is the exposure class found?
From table C2 using the exposure conditions in the question.
Where is shear force maximum in a beam?
At the supports
How is Ved Max calculated for a simply supported beam?
WL/2
What locations are:
Ved1, Ved2
Calculated at?
Ved1 = the face of support
Ved2 = a distance ‘d’ away from the support face
How are shear forces in a beam converted to shear stresses?
/ 0.9 x beam width x effective depth
What are shear stresses compared to?
Concrete strut capacity, Vrd
Where is Vrd found?
Table C4 of EC2
What value is used for minimum area of shear reinforcement required?
Whichever the greater value of Asw/s is between the calculated and the value from table C5
How is maximum link spacing calculated?
0.75 x d
How is a beam checked for deflection?
Permitted span/d ratio > actual span/d ratio
If possible, how many reinforcing bars should be used?
4
How many sections are there to the eurocodes?
10
What is the relationship between bending moment (BM) and shear force (SF)?
Where BM is max, SF is zero, and vice versa
What is cover equal to?
Higher value between nominal cover to reinforcement and
Min axis distance to soffit - shear dia. - half main bar dia.
