# Whats The Best Base Material For Concrete Driveway



## SeniorSitizen (Sep 10, 2012)

Compactable sand and forget the un-necessary plastic.


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## BaseMaterial (Oct 2, 2015)

Everything I read and everyone I talked to said sand is the worst...

Is compactable sand different from normal sand?


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## concretemasonry (Oct 10, 2006)

Use what is commonly referred to as "Class 5", which is used state-wide by many organizations. Some people feel the a material with some crushed rock is better, but with the amount and number good aggregates, even great bases can be made/blended with the very common rounded glacial aggregates. In the end, you need a proper gradation for the aggregates blended if they are not available as-is in the ground.

Dick


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## SeniorSitizen (Sep 10, 2012)

BaseMaterial said:


> Everything I read and everyone I talked to said sand is the worst...
> 
> Is compactable sand different from normal sand?


I don't know if there is a normal sand. There is beach sand, mason sand, concrete sand and many other classes I suspect. But the sand pictured is common for construction such as a base for concrete pours and it resembles yet another class of sand commonly referred to as foundry sand. At a preferred moisture content it can be compacted for castings but will crumble in the hand when dryer. This is about the simplest base available without mixing several ingredients so it's preferred by contractors because of cost and it has worked for years.


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## Canarywood1 (May 5, 2012)

BaseMaterial said:


> Hi
> 
> Can someone please tell me the difference between these and which is the best for Southern Minnesota? Long cold winters and clay soil
> 
> ...




With your clay soil i'd go with either gravel or crushed concrete as your base, just be sure you compact it in lifts according to depth.


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## Msradell (Sep 1, 2011)

Gravel is the preferred medium for base material all over the country and if noted by previous posters is what's used by highway departments. Sand is much easier to use because it can be graded and compacted very easily. The problem with it is it doesn't drain the water can build up in it and cause heaving when the temperatures get cold.


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## SeniorSitizen (Sep 10, 2012)

Have you ever seen the highway department try to compact gravel for a base when building a concrete or asphalt highway. I doubt it.


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## Msradell (Sep 1, 2011)

SeniorSitizen said:


> Have you ever seen the highway department try to compact gravel for a base when building a concrete or asphalt highway. I doubt it.


It's done all the time! On the other hand I've never seen a highway department in sand base when building highway at all.

For reference what you read this specification manual from Illinois: http://www.idot.illinois.gov/assets...uction/standard-specifications/12specbook.pdf
Section 300, specifically 311 Talks about compaction of the subbase.


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## ron45 (Feb 25, 2014)

SeniorSitizen..

In my neck of the woods...
The dirt you showed looks like what we call select. It's used for highway, main roads, some secondary roads, and back filling for trenches, etc.. Basically, anywhere the existing dirt is considered no good.

We normally use crush & run.


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## BaseMaterial (Oct 2, 2015)

Canarywood1 said:


> gravel or crushed concrete


whats the advantages and problems of both? Which is better? Thanks!


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## Canarywood1 (May 5, 2012)

BaseMaterial said:


> whats the advantages and problems of both? Which is better? Thanks!



I don't believe there's an advantage or problem of using either one for your purpose, since they are both accepted by the Federal government and probably most state governments, whatever is readily available at the best price.


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## SeniorSitizen (Sep 10, 2012)

Msradell said:


> It's done all the time! On the other hand I've never seen a highway department in sand base when building highway at all.
> 
> For reference what you read this specification manual from Illinois: http://www.idot.illinois.gov/assets...uction/standard-specifications/12specbook.pdf
> Section 300, specifically 311 Talks about compaction of the subbase.


Put rocks in a wood box and try to compact them.


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## Canarywood1 (May 5, 2012)

SeniorSitizen said:


> Put rocks in a wood box and try to compact them.


 If you have a difficult site where compaction of a stone base is a problem, you could simply switch to pug mill, and the problem is resolved.


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## Daniel Holzman (Mar 10, 2009)

From a geotechnical standpoint, the only difference between gravel, sand and silt is the size of the particles. Gravel particles are the largest, typically 1/8 inch or larger, sand is in the middle, and silt particles are very small (not visible with the naked eye).

Sand is often made of silicon dioxide, but can be made of any material that is hard enough to retain shape (crushed granite, crushed limestone, crushed concrete are considered sand if the size is correct).

The advantage of sand and gravel in road base is that they drain well. Silt, organics and clay drain poorly, so are normally excluded from road base. If the road base consists of graded material (many different sizes of particles), it can be compacted using vibratory equipment or rollers. Well compacted subbase is stronger than uncompacted subbase, will not settle much under load, and is therefore preferable.

Sand or gravel of uniform size compacts poorly, hence is considered inferior for road base to well graded material. Think of it this way, if you have a base consisting entirely of 1 inch stone, you can fill in the gaps using sand, and get a denser material that is stronger and will better support the road above.

Angular material compacts better than rounded material, so there is an advantage to using angular sand or gravel versus round sand or gravel. Beach sand is often rounded due to the action of waves, and is not as good for road base as angular sand formed by the breakdown of rock.

Conclusion: The best road base consists of a well graded mix of angular gravel and sand, properly compacted. The more silt, clay and organic in the mix, the worse it is. The more rounded the particles, the worse the mix.


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## ron45 (Feb 25, 2014)

Are we talking abut a driveway.?


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## carpdad (Oct 11, 2010)

Didn't know too much about it, but thinking that the paver driveways use stone dust (moves but supports and drains), it looks like class 5 and crusher run bases are common and historically reliable.
Search the definition of these and you'll probably conclude the same. Class 5 says some mix of clay. I think that means a "pure" mix without the contamination of clay is probably very expensive to get.


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## stadry (Jun 20, 2009)

sand does NOT compact as mentioned,,, granular base material is preferred & specified for conc by any govt agency,,, sand is not included in this definition


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## ron45 (Feb 25, 2014)




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## Bondo (Dec 8, 2007)

> *Angular material compacts better than rounded material,* so there is an advantage to using angular sand or gravel versus round sand or gravel.


Ayuh,..... I'm blessed livin' up here in Jefferson county, there's very little glacial gravel deposits 'round here,...
But,....
There's limestone bedrock quarries all 'round,....

All the driveways I build, started out as solid rock, then crushed, 'n graded to size,...
1, 1/2" minus crusher run is the most common We use,....
Easy to grade with a dozer, 'n compacts extremely well,...
Top it off with 3/4" minus, cause it's easier rakin' for final grades, before blacktop,....

Crushed stone is like a jigsaw puzzle ya pound together with the roller,...

12" / 18" of compacted crushed limestone will carry a residential driveway, Forever,....
2' for standard commercial,...
4' or more for heavy commercial, startin' with 4" minus, workin' up to 1, 1/2" minus,....

If it's over wet clay, geotextile under it, 'n ya build a bridge over the goo,...
'course, drainin' the clay if possible is even better,....


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## BaseMaterial (Oct 2, 2015)

Thanks everyone for the replies!:thumbup:


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