Grading Road base, Thickness and compaction

[Ashanstevie]

Hi all,
I was just wanting some advice and there's probably no better place than here
I've only been on a grader for around 500 hours or so.
The project I'm working on is a heavy vehicle access road and the
contractors road specs are:

12m wide road with a 3% cross fall from crown, then a 1:4 batter from shoulder to invert of drain.
I nearly have the sub-grade preped and should be ready to run gravel soon.
The road base is a 20mm aggregate and they want it 450mm thick.

So my question is what would be the most efficient/effective way of laying this?
Obviously I wouldn't run the entire 450mm lift in one go, as it would lack compaction.
Would two lifts maybe three be the best way?

Also for the final lift what thickness would You lay that, and how much higher than finished level would you go to allow for compaction and trimming?

Sorry if I made that hard to understand but
any advice would be much appreciated.

How much higher does everyone normally leave there gravel to allow for
compaction and trimming?

I'm using:
Cat 140h II with TopCon 3D gps
Cat Cs54xt vibrating Roller
Cat cw34 multi wheel roller

 

[AusDave]

The road base is a 20mm aggregate and they want it 450mm thick.

Do you really mean almost half a metre thick layer of road base?

 

[Ashanstevie]

Yes that's correct
Sub-grade is 474mm below finished level
450mm road base
24mm two coat seal

I know it's a lot of road base but that's the company's specifications

 

[Ashanstevie]

The job is on the APLNG line, West Queensland, Australia

 

[biggrader]

IMO, I would shoot for 3 lifts of 150mm each. Allow for a 10-15% compaction.( ie lay the first one out at 165mm thick... compact and proceed to the next lift.) I see that you have topcon gps and I am guessing that you have the road profile programmed into it so set the first lift at 285 mm below finished grade....compact and proceed to the next lift. Not sure of the road base you are using but after the first lift you should be able to get a better grasp of the actual compaction factor as you move to the second and third lift.

 

[Queenslander]

The job is on the APLNG line, West Queensland, Australia

We have to do a similar job on the other line just to the East.
500 mm of compacted gravel but no seal.
More big rain forecast for the next few days,not good for building pipelines.
Cheers,Greg

 

[Simpson]

Hey Queenslander,

Can you recommend any equipment dealers in Queensland? Anywhere where I could pick up a truck mounted compressor or welder (or both.) I guess they don't necessarily need to be in Queensland

 

[Queenslander]

Simpson,
I assume you will be working over here,if so, in what area?
Qld is a big state.
Cheers, Greg

 

[Simpson]

haha yea, I guess so. Brisbane area

 

[Queenslander]

The reason I asked is that we are about four hours inland, so when buying this sort of gear I try to stay as local as possible to help with after sales problems.
But if you're going to be in Brisvegas you won't have any problems getting what you need there.
What sort of application are you talking about?
Cheers, Greg

 

[JDOFMEMI]

When we lay roadbase here, the spec usually calls for no more than 6" loose lifts, sometimes 4" on tight jobs. That would roughly translate to 150 mm or 100 mm, if I am correct.

 

[Simpson]

The reason I asked is that we are about four hours inland, so when buying this sort of gear I try to stay as local as possible to help with after sales problems.
But if you're going to be in Brisvegas you won't have any problems getting what you need there.
What sort of application are you talking about?
Cheers, Greg

I'm looking for maybe a diesel or hydraulic drive compressor, a Lincoln Ranger; possibly a Miller 302 Air Pak, or some other type of multifunction unit like the enpak.