The Amazing Concrete Mixer: How Liquid Turns Into Rock
In The Amazing Concrete Mixer: How Liquid Turns Into Rock, presenter and motorbike racer Grace Webb takes us inside a self-loading concrete mixer! She explains how concrete starts as a liquid made from sand, cement, rocks, and water, and then hardens into rock. Join Grace as she shows off the driver's cab with its spinning seat and controls, then fills up the mixer and watches the liquid flow out, ready for building! This video is excerpted from BBC’s Grace’s Amazing Machines, a children’s show that introduces kids to some of the biggest, fastest, and most amazing machines in the world.
Lesson Express
Q: Why is it important for the concrete to be mixed well in the spinning barrel drum?
A: Mixing the concrete well ensures that all the ingredients blend evenly, which makes the concrete strong and reliable. If it's not mixed properly, the concrete might not harden correctly, which could lead to weak buildings.
Q: How does the driver’s cab help the operator control the concrete mixer?
A: The driver’s cab has a steering wheel and buttons that allow the operator to move the mixer and control the mixing process. This makes it easier to drive and ensures the concrete is mixed and poured correctly.
Q: What might happen if you didn’t add enough water to the concrete mixture?
A: If there isn’t enough water, the concrete might not mix well and could become too dry. This would make it hard to pour and shape, and when it dries, it might crack and not be very strong.