SUPERPAVE Digest 196

Topics covered in this issue include:

6) need opinions on Voids Total Mix

by

9) Re: need opinions on Voids Total Mix

by "Christopher Bacchi" <>

12) Re: need opinions on Voids Total Mix

by

13) Re:need opinions on Voids Total Mix

by "Richard L. Bradbury" <>

15) Re: need opinions on Voids Total Mix

by

·  To:

·  Subject: need opinions on Voids Total Mix

·  From:

·  Date: Fri, 18 Jun 1999 11:11:31 EDT

Hypothetically, lets choose a 19.0 mm SUPERPAVE mix to be placed at a depth

of 50 mm to 100 mm in a pavement structure designed for 0.3 to 3.0 Mill

ESAL's. Let's also assume that all field conditions are ideal and that all

rolling is performed correctly (this is a BIG assumption).

In Your opinion, which of the following voids criteria would give you

a better HMA product?

#1 VTM = 3.5% (% passing #200 = 5.0%)

#2 VTM = 4.5% (% passing #200 = 4.4%)

Please assume the mixes are exactly the same with the exception of the %

passing the #200 sieve.

I would really appreciate anyone's opinion on this matter.

Thank you

Mike S. (202-635-3716)

Fort Myer (Washington DC)

·  To:

·  Subject: Re: need opinions on Voids Total Mix

·  From: "Christopher Bacchi" <>

·  Date: Fri, 18 Jun 1999 13:38:15 -0400

We feel that the 4.5% void mix would be better. It should be less likely to

rut and should also be somewhat stiffer due to less 200 material....

Chris Bacchi

NCDOT

·  To:

·  Subject: Re: need opinions on Voids Total Mix

·  From:

·  Date: Fri, 18 Jun 1999 13:40:15 -0500

My vote is for option 2.

You may find that option 1 is more workable. We expect 94% roadway density with

1% total average variance and none over 2% variance from density.

·  To: ,

·  Subject: Re:need opinions on Voids Total Mix

·  From: "Richard L. Bradbury" <>

·  Date: 18 Jun 1999 15:31:50 -0400

Theoretically, I say probably No. 2 is better. Realistically, I'm not sure you'd

see much difference on the road.

·  To:

·  Subject: Re: need opinions on Voids Total Mix

·  From:

·  Date: Fri, 18 Jun 1999 19:11:50 EDT

we just put down 1500 tons of 19mm with 4.5 design voids. Looks very open but

should resist rutting (fingers Crossed)

SUPERPAVE Digest 198

Topics covered in this issue include:

1) Re: need opinions on Voids Total Mix

by Douglas Coleman <>

·  To:

·  Subject: Re: need opinions on Voids Total Mix

·  From: Douglas Coleman <>

·  Date: Sun, 20 Jun 1999 08:08:00 -0500

I believe no. 1 may be best for your conditions however I would make sure the

fines / % ac is less than 1.2. This mixture can be compacted in the field

to lower voids, which will reduce the changes of striping, and because your

traffic volumes are low i do not believe rutting will be an issue.

SUPERPAVE Digest 199

Topics covered in this issue include:

1) Re: need opinions on Voids Total Mix

by

·  To:

·  Subject: Re: need opinions on Voids Total Mix

·  From:

·  Date: Mon, 21 Jun 1999 10:33:29 -0400

NYSDOT has chosen to go with 4.0% VTM, so we're right in

between your two options. Of course, most of our contractors would

prefer 3.5% since this would theoretically be easier to compact in

the field. However, the -200 content (fines/AC actually) needs to be

monitored carefully.

Milt LaSalle