Concrete Masonry Unit 3D model is available on CGTrader for $5. Original author: imageobject. Specs: 9054 polys, 9054 verts.
OBJ (OBJ, filesize: 268 KB), BLEND (Blender, filesize: 1 MB), FBX (Autodesk FBX, filesize: 351 KB), TEXTURES (Textures, filesize: 103 MB), PNG (PNG, filesize: 103 MB), MAX (Autodesk 3ds Max, filesize: 103 MB)