Bridge Unit Study - Lesson 1: Concrete

Lesson 1: Concrete

My son made concrete, built two model bridges and tested them to see which one was stronger.

I couldn't be happier with the book Bridges: Amazing Structures to Design, Build & Test (Kaleidoscope Kids), which I purchased to give my son another hands-on engineering experience. With two parents holding engineering degrees, it's only natural that my son would have an engineering mind.

The book begins by describing the three main types of bridges: beam, arch and suspension. It gives examples of each, explains how they carry loads and discusses the advantages and disadvantages of each type. Perfect! The book starts with the big picture, explains in simple language and builds with each chapter so that kids come away with a thorough understanding of bridge construction. Although it is written for educators to use as a spine for group lectures, I just gave it to my son, instructed him to read it and do any activities he thought would be interesting. He jumped right in.

One of the first projects he did was make concrete.

To make concrete he needed to gather some sand, and some rocks.

Then he added some cornstarch and water and used an old pot to heat the mixture.

Following the directions in the book, he took the mixture and formed it into an arch bridge and a beam bridge.

Once it cooled down, he placed a load onto each bridge and added coins for weight.

Eventually the beam bridge gave way. Super. He learned the ingredients in concrete and that arches are stronger than beams.