Thermal Expansion of concrete

[The_Fritz]

Homework Statement

A concrete highway is built of slabs 14 m long (20 degrees Celsius)
How wide should the expansion cracks between the slabs be (at 15 deg Celsius) to prevent buckling if the range of temperature is - 30 deg Celsius to 48 deg C?

Homework Equations

$$\Delta$$L=$$\alpha$$L_0$$\Delta$$T

The Attempt at a Solution

Coefficient of Linear expansion ($$\alpha$$)for concrete at 20 deg C = 12*10^-6

$$\Delta$$L = (12*10^-6)(14m)(48-15 deg C) = .005544 m

$$\Delta$$L = (12*10^-6)(14m)(-30-15 deg C) = -.00756 m

Total range = .0055m + .0076m = .013m

 

[anathema]

To prevent buckling, the expansion cracks should be at least 1.3 cm wide. This will allow for enough expansion and contraction of the concrete without causing buckling. However, it is recommended to have a slightly wider expansion crack (around 2-3 cm) to account for any potential variations in temperature and to ensure the safety and stability of the highway.

 

[kerimek]

To prevent buckling, the expansion cracks should be spaced at least .013m apart. However, it is recommended to add a safety factor of at least 10% to account for any unforeseen circumstances. Therefore, the expansion cracks between the slabs should be spaced at least .0143m (14.3 cm) apart to prevent buckling. It is important to also consider the type and thickness of the concrete, as well as the amount of traffic and weight on the highway, to ensure the safety and stability of the structure.