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Why do cement trucks turn? |
by Brian Griffin (whyzz writer) >> more about the author
Beach Building
Do you have sand that you can play with? Maybe at the beach or in a sand box at your home? Try building a sand castle and think about how the sand acts like cement.
Can you build a castle with very dry sand? Chances are, that will be tough! You need to wet the sand to make it sturdy, but if you add too much water, it will be a sloppy, muddy puddle! Can you find the perfect mixture to make a castle?
Have you ever seen a cement truck on the road? They are pretty easy to spot because they have a huge tank on the back that actually spins. Inside the tank is a combination of dry cement (or concrete) and water. The spinning tank is actually acting like a big mixer! Cement comes in a dusty, powdery form, but when you mix in water and let it dry, it actually hardens like a rock! Because of this, cement can be used for many construction projects, including the sturdy foundations of buildings.
Once cement hardens, it's permanent. You can't get wet cement again. That's why it's often mixed on the way to the construction site. Sometimes though, cement is mixed at a cement plant (where cement is made) and then delivered in a dump truck, but that only works if the construction site is nearby the cement plant. If the cement sits in the dump truck too long, it will harden, and then it will be stuck there!
By mixing on the go, cement stays wet! When it gets to the construction site it is ready to use.
Once cement hardens, it's permanent. You can't get wet cement again. That's why it's often mixed on the way to the construction site. Sometimes though, cement is mixed at a cement plant (where cement is made) and then delivered in a dump truck, but that only works if the construction site is nearby the cement plant. If the cement sits in the dump truck too long, it will harden, and then it will be stuck there!
By mixing on the go, cement stays wet! When it gets to the construction site it is ready to use.
Beach Building
Do you have sand that you can play with? Maybe at the beach or in a sand box at your home? Try building a sand castle and think about how the sand acts like cement.
Can you build a castle with very dry sand? Chances are, that will be tough! You need to wet the sand to make it sturdy, but if you add too much water, it will be a sloppy, muddy puddle! Can you find the perfect mixture to make a castle?
