Sand wash used as driveway

[rustybe]

The access to our project is along a soft sand wash. 4 wheel drives have problems and the wash is in a flood plain so we need materials that can withstand flooding but not erosion. Any ideas on materials that would help compact the sand. Considering gravel, crushed rock and even plant material.

 

[cvg]

go with a well graded crushed rock, at least for a base course. gravel and sand will generally not compact sufficiently to drive on.

 

[GoldDredger]

You might consider cement treating the sand, forming a low strength grout.

Is a concrete drive out of the question?

 

[cvg]

good idea, if the fines content is low - 4 - 6 percent cement will give you about 700 psi at 7 days compressive strength. If fines are high, than you will need more cement. Best way to do this is a mixing plant. Mixed in place is not quite as good.

 

[oldestguy]

Don't use ordinary crushed rock at 3/4" max size, commonly used for roadway base course. It can erode easily under fast flowing water, even if compacted with traffic. I know having had to deal with this for our local community under heavy flow conditions.

To stabilize uniform sand, which you may have there, I'd go for a layer of what we call "beaker run rock". This usually is well graded blasted dolomite from about 4" down to fines having been run through a rock crusher. It can be worked into that sand in layers to stabilize it also.

Once you experiment with thin layers on the sand, you will see what it takes to make it stable. I'd guess at least 6 inches.

In this area some communities use this for a base layer upon which they later spread the 3/4" gravel because breaker run is difficult to blade smooth.

If you have no such quarry rock breaker run, maybe coarse gravel, with cobbles and boulders run through the crusher will also do it. You need the big sizes in the mix.

 

[Ron]

Use crushed concrete. It is a good base material, can be mixed with sand to stabilize and will go through some autogenous cementation to create a very stable material.

 

[cvg]

crushed concrete can be good, but it depends somewhat on what the original concrete mix used for aggregate and how well it was crushed. If the concrete used just pea gravel instead of crushed rock (such as is sometimes used for grout), it won't be so good.

 

[Ron]

cvg...the original aggregate, assuming soundness, has little to do with the performance of crushed concrete. It is the crushed particles and their angularity that act as new aggregate to give interlock and graded continuity.

 

[cvg]

Ron
agreed it is the crushed particles that give the performance - but you are making my case. It depends on the qualities of the crusher run. There are no specs for recycled aggregate, so you get whatever the recycler has made. What is the size of the final product and how well is it graded? Has it been crushed to a large size or clear down to the original aggregate? It might be excellent material for this application and it might not, depends. It would require a trip to the recycler to look at the stockpile and then determine if it will be acceptable for the job. Before spending a lot of money importing the material to the job, best to find out what you are buying.

 

[Dozerman56]

A maybe 8" - 12" lift of something like railroad ballast 2" - 4" aggregate could turn the trick.