# Homework Help: Heat Conduction

1. Mar 22, 2006

### MetalCut

Help with Heat Conduction Question

My question is:

These days they reinforce concrete walls with steel bars. Would the steel bars enhance or degrade the insulating value of the concrete wall? Explain?

Metal is a good conductor and concrete is a good insulator. My answer so far is that it would degrade the insulating value, because the steel bars inside would conduct the bit of heat that is contained in the concrete, so the concrete will then actually conduct more heat from the outside, thus degrading the insulating value. I'm not sure if this is right.....

Is this true or am i missing the point? Please explain, if i'm wrong.

Thanx

Tinus

2. Mar 22, 2006

### Tide

What would the answer to your question be if you replaced all the concrete with steel - except for a very thin layer of concrete on the surface? :)

3. Mar 22, 2006

### MetalCut

Well, the steel will just warm up more quickly inside because of the thin layer of concrete, because the heat have to pass through a thinner amount of concrete. I think. So, will the steel then enhance the conducting value of the concrete either way, because the steel acts as a heatsink basically on the inside, keeping the concrete cool. Help me out here, im in the dark.......

Thanx

MetalCut

4. Mar 23, 2006

### prsident21ct

I think the steel bars are all contained in the concrete, then the two sides of these steel bars is concrete, so the steel bars can suck heat from one side of the concrete, and they conduct these heat to the other side, but this conducting will be not easy because of the concrete's insulating of heat, so I think the steel bars more or less degrade the insulating value,but it is not critical.