Thermal Effects in Beams
Beams are responsible for supporting surrounding structures by not bending when a load is applied to them. Materials commonly used for forming beams include wood, reinforced concrete and steel. These different beams vary in their cost, aesthetics and physical properties. In this context, thermal resistance refers to a beam's ability to maintain its structural integrity when subjected to artificial and natural changes in temperature.-
Steel
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Steel beams are made from a special type of steel known as structural steel. The properties of structural steel -- such as its hardness, yield strength, elastic modulus, tensile strength, density, tensile strength and its Poisson's ratio -- must fall within a certain range. The thermal properties of structural steel include the measurement of how much heat must be added to it before its temperature is raised by a certain amount. This is known as its specific heat. In structural steel made from alloys, this is between 452 and 1499 joules per kilogram-Kelvin. In structural steel made from carbon, it is between 450 and 2081 joules per kilogram-Kelvin.
Concrete
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The concrete beams used in construction are normally reinforced with steel bars to give them added tensile strength. One of the most important physical characteristics of reinforced concrete is its coefficient of thermal expansion is similar to that of steel. All materials have a tendency to change volume according to changes in temperature. Because steel and concrete expand at similar rates, reinforced concrete does not undergo large internal stresses caused by changes in temperature.
Wood
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Wood is the oldest form of material used for constructing beams. The effects of ambient temperature on wooden beams vary widely. Dry conditions can cause wood to expand, while wet conditions can result in shrinkage. Wood swells in the heat due to the water contained in the wood fibers expanding. The more water contained in the wood, the more it will expand. Wood exposed to higher temperatures is more likely to absorb water. The effects of fluctuating temperature can, over time, cause wooden beams to crack or warp.
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