Asphalt Pavement Reconstruction Options

[Geotech_Pavement]

Here is information on the current road condition:

0.6 mile arterial road (north bound only) with PCI of 35. The road is 32 years old.

Options are full reconstruction and full depth reclamation

Field investigation has not been performed yet. Here is what I was thinking to do for investigation:

coring/boring at 5 locations to get thickness of asphalt, base, depth & type of cracks

Subgrade Samples: bulk soil samples for R-value (used for pavement thickness design), moisture, expansion index, plasticity index

Aggregate Base: Not sure what tests need to be done for this? I appreciate your feedback on this. Some cities like to use the existing base in place to save money. How do I assess the condition of the aggregate base is good base on field and lab tests ?

perform dynamic cone penetrometer (DCP) on aggregate base and subgrade to get CBR and in-situ strength. The in-situ CBR can be compared to R value for pavement thickness design. I am not sure if DCP on aggregate base is that helpful.

What lab tests need to be done for full depth reclamation ?

I am hesitant to use FWD because it is very expensive and I am not very familiar with it. How do I convince the client to do FWD ? Some people mentioned GPR but again that can be expensive and hard to convince client.

 

[TigerGuy]

How restricted are you on elevation changes? Can you pulverize in place and build right on top of the existing pulverized material?

 

[ACtrafficengr]

What is your AADT and truck percentage?

We have had luck with cold-in-place recycling with a PCC admixture. The PCC halves the curing time and seems to improve strength. Then again, we have used it mostly on our rural collectors and local roads, not arterials.

With FDR, you're going to have a top course and probably binder course on top, which will raise the road and affect closed drainage, driveways, etc. in urban areas. In rural areas, you'll require a fair amount of fill to restore your clear roadside area and eliminate the edge drop-off.

My glass has a v/c ratio of 0.5

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[EireChch]

If you aggregate base is gravel then DCP is worthless, It will just hit a large gravel and refuse.

You need to cut out a 0.7m dia section and get a 0.6m diam plate and do a two cycle plate load test to get CBR and EV1 and EV2.

Id imagine your aggregate base is in the order of 0.6m if you ground is ok. I woudl use a 450mm dia plate, In this instance your plate will stress down to 2*450 so 900mm. The bottom 300mm of the test will be impacted by the soil supporting the aggregate base. However, since its only bottom 300mm then it is less influential on the result.