
Concept explainers
A suitable thickness of the concrete pavement if the working stress of the concrete is

Answer to Problem 20P
The suitable depth of concrete pavement is
Explanation of Solution
Given:
Design life is
Annual rate of traffic growth is
Sub grade
Stabilized sub-base is of
Modulus of rupture of the concrete is
Traffic volume data on the highway indicate that the AADT during the first year of operation is
The pavement has aggregate interlock joints (no dowels) and a concrete shoulder.
Formula used:
The design equivalent single axle load is given by,
Here,
The total ESAL is given by,
Here,
The stress ratio is given by,
Here,
The damage percent is given by,
Here,
Calculation:
The design equivalent single axle load for
Substitute
The design equivalent single axle load for
Substitute
The design headwater depth is calculated as,
Substitute
The sub grade value of
From table 20.22, "Deign
Assume a slab
From table 20.24, "Equivalent stress values for single axles and tandem axles" of book "Traffic and highway engineering" equivalent stress values can be obtained and for
The stress ratio is calculated as,
Substitute
From table 20.27, "Erosion factors for single axles and tandem axles (doweled joint, concrete shoulder" of book "Traffic and highway engineering" for
From figure 20.26, "Allowable Load Repetitions for Fatigue Analysis Based on Stress Ratio" of book "Traffic and highway engineering" for
Thus, the Fatigue analysis for
From figure 20.27, "Allowable Load Repetitions for Erosion Analysis Based on erosion factors" of book "Traffic and highway engineering" for
From figure 20.26, "Allowable Load Repetitions for Fatigue Analysis Based on Stress Ratio" of book "Traffic and highway engineering" for
From figure 20.27, "Allowable Load Repetitions for Erosion Analysis Based on erosion factors" of book "Traffic and highway engineering" for
The table showing the allowable repetitions for
Load | Fatigue analysis | Erosion analysis |
| Unlimited | Unlimited |
| | |
Table (1)
So the
Assume a slab
Calculate the equivalent stress.
From table 20.24, "Equivalent stress values for single axles and tandem axles" of book "Traffic and highway engineering" equivalent stress values can be obtained and for
The stress ratio is calculated as,
Substitute
From table 20.27, "Erosion factors for single axles and tandem axles (doweled joint, concrete shoulder" of book "Traffic and highway engineering" for
From figure 20.26, "Allowable Load Repetitions for Fatigue Analysis Based on Stress Ratio" of book "Traffic and highway engineering" for
Thus, the Fatigue analysis for
From figure 20.27, "Allowable Load Repetitions for Erosion Analysis Based on erosion factors" of book "Traffic and highway engineering" for
From figure 20.26, "Allowable Load Repetitions for Fatigue Analysis Based on Stress Ratio" of book "Traffic and highway engineering" for
From figure 20.27, "Allowable Load Repetitions for Erosion Analysis Based on erosion factors" of book "Traffic and highway engineering" for
The table showing the allowable repetitions for
Load | Fatigue analysis | Erosion analysis |
| Unlimited | Unlimited |
| unlimited | |
Therefore, the
Conclusion:
Therefore, the suitable depth of concrete pavement is
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Chapter 20 Solutions
Traffic And Highway Engineering
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