Concrete driveway extension 4" or 6" for DP 37-40??

[Contender]

Getting ready to get a DP - 37-40' and need to widen my driveway 8' - should I go 4", 5" or 6" - THX !!

[jcgribks]

I'd go 6". I was going to put in a driveway lead in and was told it had to be 6". You don't want it to start to crack all up.

[1doodadd]

Order 3000 psi mud 1" minus rock if you can get by without a pump. Pump the mud you will have to go owith 3/8" rock but still 3000 psi. I would go with 5" and at least #4 rebar. I just did and extension and Had #5 on hand and used that. My coach is 53000 lbs

[Sweetbriar]

Might be easier on the budget to go with a high PSI grade of material then to increase the thickness.

[tnedator]

Originally Posted by 1doodadd

Order 3000 psi mud 1" minus rock if you can get by without a pump. Pump the mud you will have to go owith 3/8" rock but still 3000 psi. I would go with 5" and at least #4 rebar. I just did and extension and Had #5 on hand and used that. My coach is 53000 lbs

What kind of centers did you lay the rebar mat?

I'm about to pour a slab for an RV garage. I've had an 8" plus base (some thicker where it was lower) of hard packed sp something or other (can't keep the SPs straight), and then in all but the footers, another 7" of drain rock with a plan for 5"-6" of concrete (5" being the minimum we are shooting for), with a 12" monolithic footer around the edges for the building to rest on.

They are telling me a 3' mat is plenty for this use, especially considering how well the base has been laid. They were suggesting 4000 PSI and I was also thinking about having fiber added for a belts and suspenders approach (they feel the fiber is overkill).

[MRUSA14]

I would rather overkill than underkill. Spending a bit more now could save you from spending a lot more later.

[1doodadd]

4 foot centers. I went with 3000 but you may need to go with 4000 with that thick of base. You should go for at Least 90% compaction for your base material, 95% is common an most projects. You haven't said where you live and are doing this project? Does it freeze where you are? A lot of rain? If you really want the best results and Yes for the 2 questions, I would go with 4000 and fiber but still stay with #4 at 4 foot centers. Just make sure you have perimeter steel also Don't tie into the footing with the steel rebar from the slab, let it float, thats what your perimeter steel is for

[deaton]

I did my whole drive with 6 inch, 3500 psi, with #4 rebar tied on 1 foot centers. This was over Eight inches (nominal) of compacted road base with natural limestone rock underneath.

So far, not a crack!

Given what it takes to do this work I think you will find, after running the numbers, that a little extra on the front end to avoid problems down the road is worth the difference.

[tnedator]

Originally Posted by 1doodadd

4 foot centers. I went with 3000 but you may need to go with 4000 with that thick of base. You should go for at Least 90% compaction for your base material, 95% is common an most projects. You haven't said where you live and are doing this project? Does it freeze where you are? A lot of rain? If you really want the best results and Yes for the 2 questions, I would go with 4000 and fiber but still stay with #4 at 4 foot centers. Just make sure you have perimeter steel also Don't tie into the footing with the steel rebar from the slab, let it float, thats what your perimeter steel is for

That was the plan, perimeter steel, but not tied into the slab mat. I'll have to check on the compaction. It's Arkansas, so mild freezing for short periods.

I'll have to check on the compaction. I didn't actually talk compaction with him. This is Arkansas, so unfortunately many times things are eyeballed more than precise.

I know that we removed 6+" of top soil and then filled back with with crushed stone which requires minimal compaction, but I'm not sure how he did final compaction of the crushed stone.

Unfortunately, with my schedule I haven't been out there all the time (it's actually on my brother in laws property).

[Hgrace56]

Base is most important. Did our front drive 8" recycled concrete base on compacted earth then pavers. Rated go 60k lb coach. Has been great.

[coachmanjay]

A couple of quick thoughts about concrete. The important load factor is not the weight of the MH but the tire pressure. There will be two types of cracking Flexure or bending and shrinkage. The rebar is to control the stress cracks from bending along with minimizing shrinkage cracks, fiber does a good job of controlling shrinkage cracks. Wire mesh and fiber is a good combination. Another fact, the higher the strength the more brittle the concrete and thus longer cracks, think of glass vs hard rubber. 3500 psi is more than adequate as you have a good base, just make sure it is well compacted. Another useless fact, a women,s high heal will exert pressure on the slab around 800 psi vs 120 psi in your MH tires.

[Busskipper]

Originally Posted by Contender

Getting ready to get a DP - 37-40' and need to widen my driveway 8' - should I go 4", 5" or 6" - THX !!

Without the proper Base/Gravel/Crusher run the thickness and the rebar are just Guesses.

Get a Good Base and any of your options will work.

JMHO,

[CountryB]

Originally Posted by tnedator

I was also thinking about having fiber added for a belts and suspenders approach (they feel the fiber is overkill).

Don't bother with the fiber - the fiber strands are too short to provide any crack protection, and they make finishing the surface a pain.