What do you want to use them for? I have a friend that used a broken sidewalk for a retaining wall. They just let the exposed edge show. Guess it depends on your style. Billie

Here's an example of what Billie mentioned. Depends on how much you have.

tj

Here is a link that might be useful: Broken concrete wall

Here in the U.S., those chunks of concrete are called 'urbanite', and is considered a low-cost (but heavy) building material. It appears to be used just like stone.

One article on it is below.

Here is a link that might be useful: 'Urbanite for Suburbanites'