Tee Slab Deflection Analysis

Objective: Check of the slab deflection analysis

Task: Verify the correctness of the deflection calculation

References: Guide on designing of concrete and reinforced concrete structures made of heavy-weight or lightweight concrete (no prestressing) (to SNiP 2.03.01-84), 1989, p. 140-141.

Initial data file:

Example 59.SAV
report – Arbat 59.doc.

Compliance with the codes: SNiP 2.03.01-84*. 

Initial data:

l = 5,7  m Slab span
b×h = 80×300 mm Slab section sizes
а = 31 mm Distance from the center of gravity of the reinforcement to the compressed edge of the section
As = 380 mm2 (1Ø22) Cross-sectional area of reinforcement
ql = 8,75 kN/m Permanent and long-term distributed load

Concrete class
Class of reinforcement

В25, D1600
А-II

ARBAT initial data:

Importance factor  γn = 1

Structure:

Section:

b = 80 mm
h = 300 mm
b1 = 730 mm
h1 = 30 mm
a1 = 20 mm
a2 = 20 mm

 

 

 

Reinforcement

Class

Service factor

Longitudinal

A-II

1

Transverse

A-I

1

 

Specified reinforcement:

Span

Segment

Length (m)

Reinforcement

Section

span 1

1

5.7

S1 - 1Ø22

 

 

Concrete:

Concrete type: Lightweight
Concrete class: B25
Grade by average density: D1600
Aggregate: Artificial dense
Density of concrete 1.6 T/m3

Hardening conditions: In steam-curing chambers
Hardening factor 1

 

Service factor for concrete

γb2

allowance for the sustained loads

1

 

resulting factor without γb2

1

 

Conditions of operation:

Mode of concrete humidity - Natural humidity
Humidity of environmental air - 40-75%

Comparison of solutions:

Check

maximum deflection

Guide

23,2 mm

ARBAT

22,905 mm

Deviation, %

1,3 %

Comment. The difference in the results is due to the fact that approximate empirical formulas are used in the Guide.