Materials science — concrete, steel, timber

What you'll learn

1. 1

   Imagine you're building a bridge. You need materials that are strong, cheap, and last a long time.

2. 2

   Which of these is NOT a building material we're looking at?

3. 3

   Concrete is like a man-made rock. It's made by mixing cement, sand, gravel, and water. It's great at squishing (compression) but weak at stretching (tension).

4. 4

   Steel is a strong metal. It's fantastic at both squishing AND stretching. That's why you often see steel beams and cables in buildings and bridges.

5. 5

   Timber is wood from trees. It's renewable, lightweight, and good at squishing along the grain. But it can rot or burn if not treated.

6. 6

   Let's compare concrete and steel for a bridge beam.

7. 7

   Which material is the BEST at resisting tension (stretching)?

8. 8

   Timber is a renewable material. What does 'renewable' mean?