system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what happens to the water used to make concrete?

Can the concrete degrade, until the water escapes?
gpt
Concrete setting is a complicated process and depends on the materials used. But part of the process is the hydration of the ingredients. The water actually becomes part of the ingredients. The water remains but is part of the chemical components. Concrete is also produced which will set under water. The Romans understood how to make concrete including underwater concrete. It is part of how they were so good at construction.