SUPERPAVE Digest 27

Topics covered in this issue include:

1) Estimate VMA?

by "Kenneth Hobson" <>

2) RE: Estimate VMA?

by

3) RE: Estimate VMA?

by "Robert B. McGennis" <>

Date: Tue, 19 Aug 97 08:59:59 +0600

From: "Kenneth Hobson" <>

To: "Superpave Listserve" <>

Subject: Estimate VMA?

Does anyone have a method for estimating the %VMA? We know the effective specfic gravities of all

aggregates, fine angregate angularity as well as other aggregate properties. We could do bulk gravities on

each aggregate.

I am thinking of some kind of relationship that will get us in the ball park. My main enphasis is for superpave

designs but it should apply to other design methods.

------

Work email:

Home email:

Home Page: http://www.telepath.com/khobson

Wpwin Tips: http://www.telepath.com/khobson/listserv.html

Work Phone: 405-521-2677

Work Fax 405-522-0552

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Date: Wed, 20 Aug 1997 01:38:00 -0500

From:

To:

Cc:

Subject: RE: Estimate VMA?

Great question!

Call IL DOT. IL estimates available voids by using a Unit Weight bucket

(borrowed from Portland cement concrete mix designs.) I believe that

this method has proved successful for them.

------

Phil Blankenship

Koch Materials Company

PO Box 1875

Wichita, KS 67201

Voice (316) 828-8495

Fax (316) 828-7385

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From: Kenneth Hobson

To: Superpave Listserve

Subject: Estimate VMA?

Date: Monday, August 18, 1997 9:59PM

Does anyone have a method for estimating the %VMA? We know the

effective specfic gravities of all

aggregates, fine angregate angularity as well as other aggregate

properties. We could do bulk gravities on

each aggregate.

I am thinking of some kind of relationship that will get us in the ball

park. My main enphasis is for superpave

designs but it should apply to other design methods.

------

------

Work email:

Home email:

Home Page: http://www.telepath.com/khobson

Wpwin Tips: http://www.telepath.com/khobson/listserv.html

Work Phone: 405-521-2677

Work Fax 405-522-0552

Date: Wed, 20 Aug 1997 07:15:11 -0500 (CDT)

From: "Robert B. McGennis" <>

To:

Subject: RE: Estimate VMA?

Estimating VMA is a real tricky issue. I've not had much success in that

area.

One method is described in the Proceedings of the Association of Asphalt

Paving Technologists, Vol. 34, 1965, page 574. The authors are Hudson and

Davis. The procedure is based on aggregate voidage reduction factors based

on size and aggregate type. I've used that procedure a few times with mixed

results. The AAPT paper is pretty thorough. Actually, Dick Davis is still

active as a consultant. He can be reached at 1177 Pinewood Dr, Pittsburg,

PA 15243-1809. If anybody is interested in contacting him by phone, e-mail

me and I'll give you his number.

M. J. Hensley of Asphalt Institute in Little Rock, Arkansas adapted the

Hudson and Davis procedure for some of the mixes in his area. Jay can be

reached at .

Finally, Fred Martinez of ATSER in Houston has a method of estimating VMA. I

am not familiar with the methodology though.

Hope this info helps.

Bob

Robert B. McGennis

The University of Texas at Austin

512-475-7912 voice

512-475-7914 fax