Strength Analysis of a Rectangular Beam
Objective: Check the mode for calculating reinforced concrete structures in the “Reinforced Concrete” postprocessor of SCAD
Task: Check the strength of the beam section for the specified reinforcement
References: Guide on designing of concrete and reinforced concrete structures made of heavy-weight concrete (no prestressing) (to SP 52-101-2003), 2005, p. 28.
Initial data file:
SCAD 6 SP.spr
report – SCAD 6 SP.doc
Compliance with the codes: SP 52-101-2003.
Initial data:
| b×h = 300×700 mm | Section sizes |
| а = 70 mm | Distance to the c.o.g. of tensile reinforcement |
| а/= 30 mm | Distance to the c.o.g. of compressed reinforcement |
| As = 4826 mm2 (6Ø32) | Cross-sectional area of tensile reinforcement |
| A/s = 339 mm2 (3Ø12) | Cross-sectional area of compressed reinforcement |
| l = 6,0 m | Beam span |
| q = 140 kN/m | Load on the beam |
| М = 630 kNm | Bending moment |
| Concrete class | В20 |
| Class of reinforcement | А400 |
Results of the SCAD analysis:
|
N Max. 0 T
Max. 0 T |
My Max. 0 kN*m
Max. 630 kN*m |
Mz
|
|
Mk
|
Qz Макс. 42,81 Т
Max. -42,81 T |
Qy
|
|
|
Length of the bar 6 m |
|
Structural group Beam
Distance between the rebars in the first row S1 is less than the allowable value (see Sec. 8.3.3 of SP 52-101-2003) .
Elements: 1
Importance factor γn = 1
Member type - Flexural
Stress state - Uniaxial bending
|
Coefficients allowing for seismic action |
|
|---|---|
|
Normal sections |
0 |
|
Oblique sections |
0 |
|
Distance to the c.o.g. of reinforcement |
|
|---|---|
|
a1 |
a2 |
|
mm |
mm |
|
70 |
30 |
|
Reinforcement |
Class |
Service factor |
|---|---|---|
|
Longitudinal |
A400 |
1 |
|
Transverse |
A240 |
1 |
Concrete
Concrete type: Heavy-weight
Concrete class: B20
|
Service factor for concrete |
||
|---|---|---|
|
γb1 |
allowance for the sustained loads |
1 |
|
γb2 |
allowance for the failure behavior |
1 |
|
γb3 |
allowance for the vertical position during concreting |
1 |
|
γb4 |
allowance for the freezing/thawing and negative temperatures |
1 |
Humidity of environmental air - 40-75%
Crack resistance
Limited crack opening width
Requirements to crack opening width are based on the preservation of reinforcement
Allowable crack opening width:
Short-term opening 0,4 mm
Long-term opening 0,3 mm
Structural group Beam. Element No. 1
Member length 6 m
Specified reinforcement
|
Segment |
Reinforcement |
Section |
|
1 |
S1 - 6Ø32 S2 - 3Ø12
|
|
|
Results |
|||
|---|---|---|---|
|
Segment |
Utilization factor |
Check |
Checked according to SNiP |
|
1 |
1,02 |
Ultimate moment strength of the section |
|
Comparison of solutions:
|
Check |
Strength of the section |
|
Guide |
630/606,2 = 1,039 |
|
SCAD |
1,02 |
|
Deviation, % |
1,9 % |