A new cement block found under Decor / Structures, costs 0. It's preferable to be used in CAW as it might be a mission to do it in the World Editor. Use it only in World Editor as a last resource. In CAW you'll have to have 2 of the co-ordinates assigned the same values right through in every block ( pressuming your lot is placed at right angles ), to make the blocks perfectly straight and level. They measure 4,0 x 0,5 x 0,1 metres, 0,5 metres being the minimum possible gap between 2 lots. I've given it a all round ridge so they don't look like solid blocks. You can double them up where the gap between lots is greater then 0.5 metres, the Y co-ordinates values have to be identical so that it looks like one solid block and the ridges won't show in the middle of them and you can also rotate one of them slightly where the gap between lots is not parallel. The pattern used is a light asphalt. They can be tilted ( highly not advisable ). You need Ambitions or a later pack for the item to show in your game. There is an earlier post explaining how to install items in CAW.
Importing packages into CAW
Gap between lots cement block (MediaFire)
3 x gap between lots cement blocks for CAW
PS. If you're familiar with TSRW you may change the texture to suit your needs. Just make sure you "Create a new project" and give it a unique "Project Name", in case you need the original package, otherwise instead of 2 you'll only have 1 item showing in the game. It's always safer to create a new project because you always have the original if everything else fails. You might even use a flower pattern to fill up the gap.