Exposed road base - driveway construction question

[BigBassBrent]

I was hoping I could get some help planning my driveway construction. Searching didn稚 produce any answers to my specific situation but I read many posts about road construction and gained some great knowledge. Thanks TBN.

The initial portion of our driveway is going to be 12' x 200' and travels downhill at a 4-5% slope. The soil is high clay content and has a pretty high rate of shrink / swell. (So the soil reports says.)

For the road subbase, we will remove top soil down to 8 which is where the red clay begins. After the subbase is leveled and compacted we will be installing geotextile woven fabric. Then we will put 8 of 3肺1 crushed limestone for the road base. There is no fine materials in this rock. It will initially be compacted with loaded vehicles. My plan is to get this portion of road built so we can begin construction of the home site.

We hope to leave the road like this (no top coat) for the heavy construction equipment to drive on. Once construction is complete (could be up to a year) we plan to come back, add more base rock to any low spots, reshape, then add 4 of top coat gravel. For the top coat plan to use a 1 3/4" limestone road base aggregate (called city base in my area) containing a lot of fines. I may come back later and add a layer of small limestone gravel for apperance.

My question is, will I be doing any harm to my subgrade and road base by leaving it exposed to rain during home construction? Without the top coat, the water will easily enter the rock base and permeate the subbase. To help with drainage during this time, I plan to put a temporary drainage ditch at the end of the road so that water that makes it to the subbase will drain out and not collect.

Is this an OK plan or should I install a top coat before the big trucks drive on it?

Sorry for the long post, lots to explain. Thanks for any help.

Added a pic since everything is better with pics~

 

[horses2]

I am going to follow this one closely, as I have a similar project. There is a right of way running thru the middle of my hayfield and it seems the only time it is used is when the ground is soft. so the ruts are huge and the folks using it tend to run into the hayfield to avoid the ruts and they make new ruts. i am going to move the right of way in stages and am also looking for pointers on gravel road construction. I do have to remove some trees and the stumps to reroute the road. sorry if this seems like a hijack, it was not intended as such, just looking for some gravrel roadbuilding tips.

 

[Billrog]

I wouldn't be concerned with getting the top coat on maybe get an extra load set to one side in case any soft spots show up. This is normal practice here in clay so the site is accessible when it's wet. We don't have lime stone but use 3 or 4" crushed rock.

 

[Billrog]

Pic. looks like a nice place btw.

 

[SirReal63]

I won't profess to be an expert road builder, however this is what we did with our black clay muck. We did nothing for the road during construction of the infrastructure and buildings, we let the heavy equipment roll right over it and pack it. We did not let anyone drive on it during rain and waited a few days after so it dried a little. Once most of the heavy trucks were done I scarified it to remove grass and leveled it out. We did not use any fabric, just hard packed good road base. It is about 4-6" deep in most places, a little deeper in others. It has worked beautifully, it has packed down with rain and traffic to almost like concrete. The more it rains and we drive over it the harder it has packed.

Start at post 219 here for a better idea of what we used.
http://www.tractorbynet.com/forums/south/313136-small-texas-farm-beginning-22.html

My concern with your plan is without the fines, the sub base will just get pushed to the sides from the heavy trucks and tear the fabric. It is the fines that lock the pieces together as I am sure you know, without them there is nothing to keep the sub base in place. The way we did it may not be perfect but it has worked beautifully. We may go back over it with decomposed granite but we also may not, it looks good and is very densely packed. It has been a great road for being over clay.

 

[BigBassBrent]

I won't profess to be an expert road builder, however this is what we did with our black clay muck. We did nothing for the road during construction of the infrastructure and buildings, we let the heavy equipment roll right over it and pack it. We did not let anyone drive on it during rain and waited a few days after so it dried a little. Once most of the heavy trucks were done I scarified it to remove grass and leveled it out. We did not use any fabric, just hard packed good road base. It is about 4-6" deep in most places, a little deeper in others. It has worked beautifully, it has packed down with rain and traffic to almost like concrete. The more it rains and we drive over it the harder it has packed.

Start at post 219 here for a better idea of what we used.
http://www.tractorbynet.com/forums/south/313136-small-texas-farm-beginning-22.html

My concern with your plan is without the fines, the sub base will just get pushed to the sides from the heavy trucks and tear the fabric. It is the fines that lock the pieces together as I am sure you know, without them there is nothing to keep the sub base in place. The way we did it may not be perfect but it has worked beautifully. We may go back over it with decomposed granite but we also may not, it looks good and is very densely packed. It has been a great road for being over clay.

Your road looks great Jack! Thanks for the help. I had not considered the fabric tearing under the shifting loose rock. I think your on to something. I already got my truck stuck on the temp road when it was too soft. Lesson learned. I think for our situation, we may still want to get rock down for the big trucks since it typically takes 4-5 days after a rain for the temp road to be driveable. The slight uphill grade to get back to the county road makes things more difficult without some rock to roll on.

After seeing what you did and the good results you had, I think we will still follow most of our plan but instead of 8" of the 3 x 1" crushed limestone, we will put down 8" of city base and have a pile on hand to add to low spots as they show up. Then after construction, I can add a couple more inches of the city base and reshape.

The city road base I plan to use is here.

And thanks Bullrog, we looked for a long time before we found a property that we were happy with. We are very excited about getting moved out there! The wildlife is amazing, although I think the animals are a little shaken since I started running the Kubota out there!

-Brent

 

[SirReal63]

We have been very pleased with how it turned out. The guy we used has been doing it in this area for about 30 years, his suggestion appears to have been a good one. We were fortunate that we did not have a lot of rain over the summer and fall to contend with so the road got packed very well. The areas not driven on are as soft as carpet to walk on, the soil is very loose. We still about 1000' of road to do up to the backside of the property.

Most people use the limestone or caliche base here, our main road to the property is made with it. It gets dusty and the large pieces become uncovered and it makes a bumpy ride. It will be fine once it is topped though. Our base is what they called a "premium base" and all pieces are quarter size or smaller with a whole lot of fines in it. I will try a snap a pic later today of what it looks like now after the torrential rains we had in December and January.

I love your area, in Texas terms we are practically next door neighbors.

 

[GLyford]

I think you should plan on the drainage being permanent, not temporary, and built to last...the clay will tend to act like a channel keeping the water in the gravel, even after more layers are on. If you plan now on how to manage that water, I think you will be a step ahead...?

 

[BigBassBrent]

I think you should plan on the drainage being permanent, not temporary, and built to last...the clay will tend to act like a channel keeping the water in the gravel, even after more layers are on. If you plan now on how to manage that water, I think you will be a step ahead...?

I totally agree. I plan on having the ditches set up properly in this first phase. The drainage I was suggesting was because I had previously planned on using the crushed limestone with no fines as the road base and was going to leave it exposed during construction, which meant that water was going to enter the area where I had dug out the top soil to 8" below grade. I didnt want the water to collect at the bottom of the road below the road base rock. However, this is no longer an issue if I go with the city base with fines since it will compact and shed the water to the ditches. Thanks!

 

[BigBassBrent]

Jack, I am very familar with your area. We like to stop at that little El Rancho Mexican food place in Bertram after a good day of bass fishing on LBJ. We also have several friends in Liberty Hill. In my book, we are neighbors!

I look forward to seeing more pics of the road if you get a chance. Thanks.

I decided to share a pic of the same area before we started any work. It took a lot of "vision" to see what this place could be once things were cleaned up. Lots of dead oaks and overgrowth to contend with so far. The property has not been maintained, ever. It's a great feeling when things start coming together.