Check with the Florida Concrete and Products Association. They have some pretty good info on pervious pavements. Also check the Portland Cement Association....Google "Pervious Pavement" there's tons of info.
Check with the Portland Cement Association (PCA) and the National Ready Mix Association (NRMCA).
They have more volumes of information on mix designs and procedures than anyone.
Pay attention to aggregate shape/type (rounded, angular or crushed), since in many cases it can be the major factor. - It has to do with interlock (mechanical strength) in addition to cement requirements (bonding, etc.).
aaronc,
As you could gather from my previous post, I know nothing about pervious pavements. But pavements in general work best when water is kept out. Defects in the surface lead to water infiltration and potholes. So if the intent is to let water in, a different type of pavement structure below the wearing course will have to be used. Your problem may not be the mix design, but rather what is under the top layer.
aaronc..Hokie66 is correct. The subbase is important both from a support standpoint and a drainage consideration.
Also, keep in mind that pervious pavement ultimately becomes less pervious as the voids fill with debris. Some will tell you they are "self flushing". They're not. Minor flushing occurs at the surface, but below that no flushing occurs. If you are using it as part of your stormwater runoff system, consider that the runoff coefficient will be greater than gravel, but less than asphalt, at least initially.
Pervious pavements are used in some projects for LEED sustainability requirements so water from rainfall stays on the site instead of being redirected to piping/culverts which take it off the site.
aaronc,
As far as I know, the pervious pavements in current use are not appropriate for vehicular traffic.
I went to an FCPA (Florida Concrete and Products Association) seminar recently and the presenters said that pervious rigid pavement should not be used in trafficked areas.
They can be used in parking lots, but even then the aggregate will debond over time if the parking space is used frequently.
I assume you are talking about rigid pavement.
Pervious asphaltic pavement (open graded mixes) have the same problem in that there is not enough cement to properly hold the aggregate in place.
I also agree with the above statements that the pores will clog over time if not cleaned regularly.
Pervious Pavement for Roads Has been the Dream of most
environmentalist. The idea of a Reservoir under the pavement
seems enticing but sadly though no one has come up with a cheaper solution in the maintenance of your sublayers cause definitely they need yearly cleaning or replacement.
If your state is encouraging pervious pavement why used mixed design why not used Bricks their more structurally sound,durable and easier to remove for your sub
layer maintenance although significantly more expensive.
There are so many specialist in pervious surface now a days
like Unilock but mostly though theyre only doing it on parking lots and alleys.
Check them out and asked for the mixed ur asking (Unilock)
They have good inhouse case study data about pavement performance: pavers, pervious asphalt & concrete. Sorry I don’t have a contact from their presentation at AWPA last spring. They would be my recommended starting point for any northern climate design.
Thanks for the links. Doing current hillside work in the City of Los Angeles is very interesting with impervious areas and stormwater cleaning requirements right now. I hope to learn just how far we can take grasscrete or similar designs on certain projects.
CDG, Los Angeles Civil Engineering specializing in Hillside Grading
