Building Bridges – Experiment

Bridges are structures that help people and vehicles cross over obstacles like rivers, roads, valleys, or railways. 

Materials Needed:

  • Toothpicks
  • Mini Marshmallows or Gum Drops
  • Paper Cups
  • A flat surface for building
  • Optional: Paper and pencils for planning designs

Steps to build the bridge:

  • Base/Foundation: Use marshmallows or gumdrops as joints and toothpicks as beams to create a sturdy base. A wide base provides stability.
  • Structure: Build the bridge’s main structure by connecting toothpicks with marshmallows or gumdrops. Use paper cups as pillars for support.
  • Deck: Construct the deck (the part where cars would drive) on top of the structure. Make sure it’s even and firm.
  • Test: Test the bridge by placing small weights on the deck, such as coins or small toys. Add more toothpicks to stabilize as needed.


Science Behind Building A Bridge

Parts of a Bridge

  • Beams are long, horizontal parts that support the weight of the bridge deck.
  • Joints are points where different bridge parts connect, allowing for movement and flexibility.
  • Supports are strong structures like pillars that hold the bridge up and transfer its weight to the ground.

What makes a bridge strong?

  • Strong materials, such as steel and concrete, help support heavy loads.
  • Using triangles in the design helps distribute weight evenly and adds strength.


Fun Facts

Here are some interesting facts about bridges:

  • Suspension bridges, like the Golden Gate Bridge, use cables to hold the bridge deck.  
  • Truss bridges use a network of triangles to add strength and stability. The Forth Bridge in Scotland is a famous railway bridge. 
  • Arch bridges, such as the Sydney Harbor Bridge in Australia, have a curved shape that helps distribute forces evenly.



Let’s quickly recap what we learned about building bridges:

  • What are the three main parts of a bridge? Beams, Joints, and Supports
  • What materials are used in bridges to support heavy loads? Steel and Concrete
  • What shape is used in bridges to help distribute weight evenly and add strength? Triangle
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