Making a strong paper bridge requires concentration, attention to detail and a desire to learn and have fun. Many teachers ask their students to build paper bridges to teach them about the purpose and construction techniques of real bridges. Bridges are under two types of force: compression and tension. Both are in action when any weight is placed on a bridge. Compression pushes weight down on the structure and tightens it. Tension stretches the structure of the bridge. In bridge construction, the triangle is used because it supports both compression and tension.
Things You'll Need
Two wooden blocks of the same size
Several pieces of paper
Find a solid surface, like a table or the floor, that is even. Place the wooden blocks on the surface about six inches away from each other.
Use a truss bridge as the model for your construction. Roll the paper into dense tubes and tape the tubes closed. Rolling the paper will ensure that the bridge will not buckle and that it will be able to sustain compression.
Construct the truss bridge by mirroring the design of a real truss bridge. This means that you will have to design two railroad-looking formations with the paper that you have rolled. The railroad formations will provide the horizontal structure of the bridge.
Attach the railroad formations on top of each other by gluing paper rolls to evenly spaced sections of the formations. These paper rolls will be perpendicular to the railroad formations. To add even more strength to the paper bridge, glue paper rolls diagonally across the squares that were formed between the two railroad formations. Each square in the bridge will look like it has four triangles within it. You can also glue extra pieces of paper to the areas on the bridge where the perpendicular sections meet the horizontal sections. Doing this secures the attachments even more.
Place the paper bridge so that it spans the length of the wooden blocks. Add an increasing number of coins to different sections of the bridge to test how strong the bridge is.