Thermal Expansion in Concrete Bridges
How does temperature affect the gap between concrete slabs in a bridge?
On a 115°F day, the slabs just touch. What is the gap between the slabs when the temperature is 0°F?
Answer:
The gap between the concrete slabs when the temperature is 0°F can be calculated using the concept of thermal expansion.
Concrete slabs in bridges expand when heated and contract when cooled due to thermal expansion and contraction. This phenomenon is a result of the material properties of concrete.
The change in the length of a bridge due to temperature fluctuations can be calculated using the formula for linear thermal expansion, which is ΔL = αLΔT. In this case, the coefficient of linear expansion for concrete is approximately 10 x 10^-6 per °C.
By calculating the change in length when the temperature drops from 115°F to 0°F for concrete slabs that are 275 cm long, we find that the gap between the slabs will be approximately -0.835 cm at 0°F. The negative sign indicates that the slabs will contract, creating a gap between them.
Therefore, temperature plays a crucial role in determining the gap between concrete slabs in a bridge, showcasing the importance of considering thermal expansion and contraction in bridge design and construction.