Reinforced Concrete Beam Design

Question 1

What is Fck?

Answer 1

Compressive strength of concrete (cylinder)

Question 2

What is Fyk?

Answer 2

Characteristic yield strength of reinforcement

Question 3

What is b?

Answer 3

Breadth of beam

Question 4

What is h?

Answer 4

Overall depth of beam

Question 5

What is d?

Answer 5

Effective depth of beam

Question 6

What is effective depth?

Answer 6

Depth to centroid of tension reinforcement

Question 7

What is As?

Answer 7

Area of tension steel

Question 8

What is the partial factor of safety for dead loads?

Answer 8

1.35

Question 9

What is the partial factor of safety for live loads?

Answer 9

1.50

Question 10

How is design load per metre of a beam calculated?

Answer 10

(1.35 x Total dead Load/m) + (1.50 x Total live load/m)

Question 11

What is total dead load?

Answer 11

The characteristic dead load + beams self weight

Question 12

How is maximum shear force calculated?

Answer 12

Design ultimate load and effective span are used within the shear force equation

Question 13

How is maximum bending moment calculated?

Answer 13

Ultimate design load and effective span are used in the bending moment calculation

Question 14

What is effective span?

Answer 14

The smaller value between:

Distance between CL of supports

And

Clear span + Total depth

Question 15

What is step one in calculating longitudinal reinforcement?

Answer 15

Calculate k factor

Question 16

What value must k not exceed?

Answer 16

0.167

Question 17

What is step 2 in calculating the area of longitudinal reinforcement?

Answer 17

Find z/d

Question 18

What is step 3 in calculating longitudinal reinforcement?

Answer 18

Find Z

Z = d x (z/d)

Question 19

What is step 4 in calculating longitudinal reinforcement?

Answer 19

Find As

Question 20

What is step 5 in calculating longitudinal reinforcement?

Answer 20

Check As exceeds min percentage required

Question 21

What is step 6 in calculating longitudinal reinforcement?

Answer 21

Choose reinforcing bars that give a reinforcement of at least As

Question 22

What table is used to determine longitudinal reinforcement (main bar)?

Answer 22

Table C5 of EC2

Question 23

What Eurocode is used for reinforced concrete?

Answer 23

EC2

Question 24

What is effective depth = to?

Answer 24

Total depth - min cover - shear link dia. - (half main bar dia.)

Question 25

How is cover found?

Answer 25

Using table C1 and the duration of fire resistance, the value of ‘min axis distance from soffit’ = cover

Question 26

How is the exposure class found?

Answer 26

From table C2 using the exposure conditions in the question.

Question 27

Where is shear force maximum in a beam?

Answer 27

At the supports

Question 28

How is Ved Max calculated for a simply supported beam?

Answer 28

WL/2

Question 29

What locations are: Ved1, Ved2 Calculated at?

Answer 29

Ved1 = the face of support Ved2 = a distance ‘d’ away from the support face

Question 30

How are shear forces in a beam converted to shear stresses?

Answer 30

/ 0.9 x beam width x effective depth

Question 31

What are shear stresses compared to?

Answer 31

Concrete strut capacity, Vrd

Question 32

Where is Vrd found?

Answer 32

Table C4 of EC2

Question 33

What value is used for minimum area of shear reinforcement required?

Answer 33

Whichever the greater value of Asw/s is between the calculated and the value from table C5

Question 34

How is maximum link spacing calculated?

Answer 34

0.75 x d

Question 35

How is a beam checked for deflection?

Answer 35

Permitted span/d ratio > actual span/d ratio

Question 36

If possible, how many reinforcing bars should be used?

Answer 36

4

Question 37

How many sections are there to the eurocodes?

Answer 37

10

Question 38

What is the relationship between bending moment (BM) and shear force (SF)?

Answer 38

Where BM is max, SF is zero, and vice versa

Question 39

What is cover equal to?

Answer 39

Higher value between nominal cover to reinforcement and Min axis distance to soffit - shear dia. - half main bar dia.