This is a paid asset, but now you can download Concrete Colors Materials Free.
Detail this asset from Unity Store: Original Link
Concrete Colors Materials v1.0
Cement Colors Textures:
11 different cement materials showing concretes, walls, floors.- All textures, come as PNGs 512×512 pixels, with full bumpmap, and all textures are tileable (seamless), to use in different tiling scales.
An example materials in web format: Click here
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