Portland cement

Portland cement is kind of like a special glue that's used to make very strong concrete.

You know how you can mix water and flour to make a dough? Well, Portland cement is made by mixing different ingredients together too.

First, they take some rocks (usually limestone) and heat it up SUPER hot until it turns into a powder. Then, they mix that powder with other things like clay and iron.

After they mix all these things together, they heat it up again and add a few more things like gypsum. Then, it's all cooled down and turned into a kind of gray-ish powder.

When people want to make really strong concrete, they mix the powder with water and other materials like sand and gravel. Then, they pour this mixture into a mold and wait for it to dry.

The result is super strong concrete that can be used to build all sorts of things like buildings, bridges, and walls!