Question

For a 25 cm thick cement concrete pavement, analysis of stresses given the following values:
Wheel load stress due to corner loading
$=30kg/c{m}^2$
Wheel load stress due to edge loading
$32kg/c{m}^2$
Warping stress at corner region during summer
$=9kg/c{m}^2$
Warping stress at corner region during winter
$=7kg/c{m}^2$
Warping stress at edge region during summer
$=8kg/c{m}^2$
Warping stress at edge region during winter
$=6kg/c{m}^2$
Friction stress during summer
$=5kg/c{m}^2$
Friction stress during winter
$=4kg/c{m}^2$
The most critical stress value for the pavement is

• A. $45kg/c{m}^2$
• B. $42kg/c{m}^2$
• C. $44kg/c{m}^2$
• D. $40kg/c{m}^2$

Answer 1

The correct option is B $42kg/c{m}^2$

Frictional stress will be zero at the corner, and nature of frictional stress will be compressive during summer and tensile during winter.

During summer:
Critical stress at edge
= wheel load stress + warping stress - frictional stress
$=32+8-5$
$=35kg/c{m}^2\text{tensile}$

Critical stress at corner
= wheel load stress + Warping stress
$=30+9$
$=39kg/c{m}^2\text{tensile}$​

During winter:
Critical stress at edge
= wheel load stress + warping stress + frictional stress
$=32+6+4$
$=42kg/c{m}^2\text{tensile}$

Critical stress at corner = Wheel load stress + Warping stress
$=30+7$
$=37kg/c{m}^2\text{tensile}$​

Hence, most critical stress
$=42kg/c{m}^2\text{tensile}$​