Integers and Temperature

I love using real life examples of temperature up here in Alaska because we go down below zero.  Instant negative numbers with drops and rises so you are at -30 and drop ten degrees to a final temperature of -40.  Or it might be -30 and the temperature rises ten degrees to -20.

Unfortunately, this is not an easy concept to teach in many parts of the country since low temperatures may get down to 52 degrees.  I was in Hawaii, one winter, and the front desk worker was shivering because it was a cold 52 degrees F.

I laughed because that is warm to someone who'd just come from -40 or so.  In Alaska, we understand temperatures below zero but not everyone does.  We also understand that temperatures can effect the way things are built.

In many places, there are ice rinks which must be set up so the water spread over the area is frozen properly and the temperature maintained for weeks.  The temperature of the hockey rink has to be maintained between 17 and 23  degrees F (considered hared ice) which lowers the temperature of the surrounding air to between 50 and 60 degrees.  This temperature is sufficient so anytime water is spread over the existing ice, it will freeze.  On the other hand, the ice in ice skating rinks are generally kept between 24 and 29 degrees F for a softer ice that works best for ice skaters.

Many building materials react to changes in temperatures such as concrete. If the temperature drops too fast and freshly poured concrete is not properly protected, the water in the concrete freezes, creating ice crystals and the concrete looses strength.  In addition, steel can expand if the temperature goes up and it contracts if the temperature drops.

I see the results of soil being frozen during the winter at my apartment.  Someone in the past demanded they put solid skirting around the base of the building.  This meant the soil under the place didn't get as cold as that surrounding the building and its buckled causing the walls to separate from the ceiling.  I have gaps up to an inch which weren't there 13 years ago when I moved in.  Its only gotten worse over the years.  yes, occasionally they've tried leveling the building but it only lasts till everything freezes and the whole place starts pulling apart again.

What this all means is that if you are in construction, you have to plan ahead so you work at optimum temperatures for the material.  For instance, if you are pouring a concrete road in winter, you pour the concrete when temperatures begin to rise before covering it so it has a chance to set properly, otherwise it doesn't set properly and you've wasted money. On the other hand, if its the middle of summer, you might pour concrete at night when temperatures are much lower and have less effect on the setting of concrete.

There is another issue with extreme cold.  If you have a material that contracts while you are painting it or gluing it, either the paint or the glue could crack or wrinkle when the temperatures rise and the material contracts again.  This means anytime a contractor creates a quote for a project, they have to keep in mind the time of year, the temperatures, and how these temperatures could effect the timing of the project.

Just a bit on how temperature can effect buildings, construction, and materials while looking at it in terms of positive and negative numbers.  Let me know what you think, I'd love to hear.  Have a great day.