Bridge construction types

Beams:

Cross-section beams used in buildings may vary in size. Some are solid or hollow. Below are three different size beams. The first one box beam section, the second one beam section and the third one I have L section beam. Solid bars are hollow with huge smiles. As you strength and hardness of a special section bars below. He beams as strong as large, but too many can be lighter. We a good power / weight ratio as described in can.




Reinforced concrete beams

Solid doors and windows on buildings used as pieces support horizontal beams. These are called lintels. Engaged in concrete reinforced with steel rods These lintels are. Steel bars are usually placed under the neutral axis. More than one material is a combination of reinforced concrete composite materials. When under stress increased the strength of steel concrete increases.
Concrete is very strong in compression but weak in tension. One of the qualities of concrete as we describe it.

Task

1. Card and glue used three times. Test structural strength and load resistance (compression and tension in tension) for the separate beams. Between two desks or chairs we achieve this can keep time. If weight or suspended beams, we finally witness must be able to change the size of beams is kept on the top. He gives a sign of weakness. They fold or bend, depending on how much weight is hanging from them, maybe.

2. Test rapidly with heavy weight one tree. Although weight loss and weight recorded episodes of both structural size hanging if time. Place in a spreadsheet or change these results describe a graph with notes and record your results.
You watch episodes of one Newton meters or may consider using line test.

3. Once you finish your experiment illustrated folding beam or by any means the longest length of time without crumpling on was heavy weights.

4. Why was once the other two types of structurally stronger explain?

5. Such architectural structure which is used once to send?

6. With efforts to increase the power of additional beam map? Remember many additional cards, the time surcharge. The weight ratio with low power will be over.