I have an architect that wants me to build a winery a road. He doesn't want the look of pavement or the expense of concrete. So he wants me to put down a 6" 21A base (crusher run) and 3" of brown pea gravel, then spread 100lbs of portland for every 2 lineal ft. I am looking for any tips on how to make this work. The architect wants a hard road with that brown gravel look. I don't see how the portland is going to hold the brown gravel. So should I put the portland on top of the 21A base and then roll and vibrate that, then go with the pea gravel? Also on a 12' wide road do you guys think it is critical to crown the road with 2 ditches or have positive drainage across the whole road and into one ditch? Thanks for your advice.
Jim,
Your best chance to make the Portland scenario work in my opinion would be. Get your material(s) and process them together through a Pug Mill, adding the optimum moisture at that time.
I would construct your subgrade with a super elevated profile... a crown is going to be too difficult to accurately construct on a road this narrow, furthermore, most likely there is nothing that would require it. I would place this material with a paving machine; I think this would be the most effective at achieving the results you specified. You could also place and grade it with a grader and use a roller and possibly get the 3/8" pea gravel worked to the top for the desired appearance.
I think the Pug Mill will process the materials more effectively than anything short of having a batch plant mix up some 1 or 2 sack slurry.
Running aggregates through the augers on a paving machine for extended periods of time is hard on things due to the fact there are no oils to help lubricate as there is with asphalt.
See my article on road maintenance where I talk about crowns versus super elevated road designs.
I would run the numbers on the aforementioned options and see how they stack up? I am anxious to see how you proceed.