ESAL for a typical asphalt paving

[sengr]

For a 3" thick asphalt wear course, over an 8" thick base, over an 8" thick sub-base; what is the ESAL loading for this flexible pavement? One geotech engineer say roughly 1,000,000 ESAL. I think that is too high. I have used a design software and came up with 122000 ESAL. Does this sound about right? Trying to get a feel for pavement design as it is not my area of expertise. Thanks very much.

 

[LHA]

When you say 8" base do you mean binder course bituminous? If so, you have got a very beefy section there.

In general, the SN you get from 3" TOTAL asphalt (wear and binder) and 6" subbase will be good for the 500,000 to 2M range.

Engineering is the practice of the art of science - Steve

 

[LCruiser]

Depends on what it's on top of too...

 

[Ron]

sengr...you should be over 1,000,000 with that pavement section. Your structural number is on the order of 3.2 which will support a lot of traffic.

 

[LCruiser]

What if it's built on muck?

 

[Ron]

LCruiser....assumed constructability and a competent subgrade. Anything else would not be reasonably constructable (can't get compaction on soft or unstable subgrade)

 

[sengr]

Mr. lha, the 8" base is crushed limestone course only, not bituminous.

I used SpectraPave2 from Tensar Corporation, I did get SN of 3.02 but it is telling me that the allowable traffic load (ESAL's) is 122000. This does not agree with what was said. Could you guys help explain? Thanks very much.

 

[fattdad]

Provide the design CBR value and the design life for the intended pavement and we can then tell what the ESAL for the pavement section would be. As it stands, there's not enough information.

f-d

¡papá gordo ain’t no madre flaca!

 

[sengr]

Here is what the soil report says:

"We did not perform any California Bearing Ratio tests on the surficial soils at the project site. However, based on our experience we recommend a CBR value of 6 to 8 for 8-inches of lime-fly ash stabilized sandy/silty clays overlying the fill soils. A higher CBR may be obtained by increasing the thickness of stabilized soils."

Regarding the design life, that is another subject by itself. I posted the subject on this board and it ranges from 10 to 15 years. I think I am going to design it for 10 years. I did an estimated traffic calculation using common sense only. I used 1000 cars (0.36 ESAL per day), 1000 pick-up trucks (2.27 ESAL per day), 10 delivery trucks (1 ESAL per day), 50 semi trailer truck (67.5 ESAL per day), and a crane every other truck (13.3 ESAL per day); I got 308170 ESAL's for 10 years. By the way, the road is located inside an industrial plant / chemical plant. Thanks in advance.

 

[sengr]

Sorry, I meant to say a crane every other day = 0.5*26.6 = 13.3 ESAL per day.