BUILDING CONCRETE SLABS FOR STREET AND HIGHWAYS I'm beginning to favor the technique described below as it gives me more modeling options. At any rate, I don't end up with overly antiseptic look working with plastic.  The cardboard I use is from an old Priority Mail box because it's the thickness that works best. Using a carpenters square, I cut my slabs in rectangles 2' X 2 1/2". Side walks are installed first and can be made with thicker cardboard, Masonite or even soft pine paint stir sticks. The above picture has thicker cardboard. The gas station below is built on a thin Masonite base that include the sidewalks, and the buildings to the right have paint stir sticks. Working with six slabs at a time, coat the layout base with Carpenter wood glue and press them in place. Because the cardboard will curl, now coat the top of the cardboard. Use a cardboard scrap to trawl the glue flat for both applications. Now sprinkle the #1290 Concrete powder on the wet glue. Use a pallet knife to trawl the powder flat. When the powder gets to gluey from the glue below, hit the area with a light water spray to make it workable. A occasional slab can be shimmed up slightly on one edge to model a frost heave, but don't over do it.  Before the glue sets hard, clean out the joints with a sharp tool. I use a piece of brass angle as a corner tool for curbs and gutters. After everything is dry, sand away any lumps and rough edges. To model large cracks, I'll cut some of that unfinished cardboard in random jagged pieces and then install in the method described above.  I photoed the scene before everything had a chance to dry and couldn't sweep up the loose powder on the street. This does show how deep cracks in the concrete looks. I'll try to find time next week and finish everything up. The switch leads off to where the bulk tanks for all those gas stations store their fuel products and that hasn't even been started yet.