TROXLER 3191 User Manual

Manual of Operation and Instruction

Model 3191

True Mold Angle

Device

for the

Model 4141 Gyratory Compactor

Troxler Electronic Laboratories, Inc.

3008 Cornwallis Road • P.O. Box 12057

Research Triangle Park, NC 27709

Phone: 1.877.TROXLER

Outside the U.S.A.: +1.919.549.866 1

Fax: [phone]

www.troxlerlabs.com

Troxler products are protected by U.S. and foreign patents

Copyright © 2002 – 2005

Troxler Electronic Laboratories, Inc.

All Rights Reserved

No part of this manual may be reproduced or transmitted in any
form or by any means, electronic or mechanical, including
photocopying, recording, or information storage and retrieval
systems, for any purpose without the express written permission of
Troxler Electronic Laboratories, Inc.

PN 109903
February 2005
Edition 2.0

ii

TROXLER SERVICE CENTERS

Troxler Corporate Headquarters

3008 Cornwallis Road

Research Triangle Park, NC 27709

Phone: 1.877.TROXLER (1.877.876.9537)

Outside the U.S.A.: +1.919.549.8661

Fax: [phone]

Web: www.troxlerlabs.com

Technical Support

Phone: 1.877.TROXLER (1.877.876.9537)

E-mail: [e-mail]

Midwestern Branch Office

1430 Brook Drive
Downers Grove, IL 60515
Fax: [phone]

Western Regional Branch Office

11300 Sanders Drive, Suite 7
Rancho Cordova, CA 95742
Fax: [phone]

Southwestern Branch Office

2000 East Randol Mill Road
Suite 611
Arlington, TX 76011
Fax: [phone]

P.O. Box 12057

Florida Service Center

2376 Forsyth Road
Orlando, FL 32807
Fax: [phone]

Canadian Branch Office

7125 Pacific Circle, Unit 13
Mississauga, Ontario L5T-2A5
Canada
Fax: [phone]

Troxler European Subsidiary

Troxler Electronics GmbH
Gilchinger Strasse 33
D.82239 Alling nr. Munich, Germany
Phone: ++49.8141.71063
Fax: ++49.8141.80731
E-mail: [e-mail]

Model 3191 True Mold Angle Device iii

NOTES

iv

INTRODUCTION

Troxler’s Model 4141 Gyratory Compactor provides safe, reliable
gyratory compaction of asphalt specimens at a compaction pressure
of 600 kPa and 1.25° angle of gyration. The Model 3191 True Mold
Angle Device (TMA) provides a real-time display of compaction
angles, enabling the compactor operator to accurately and
independently verify the true angle of the mold while the compactor
is in operation.

To complement the TMA’s real-time data display, a True Mold
Angle software package is provided with the unit. This software can
be used to upload and store angle measurement data on a computer.

The TMA attaches to the frame of the Model 4141, and measures
the mold angle externally.

The TMA is a passive measuring device that does not interfere with
the normal operation of the gyratory compacto r. The TMA does not
affect the mold angle being measured, or the relationship between
the surface of the sample and the active ram head or ram foot.

Because the TMA is external to the mold, it does not limit the
amount of sample that can be placed in the mold during the test.
This enables the TMA to perform dynamic measurements during the
preparation of actual specimens. There is no need to extrapolate or
project possible angles for full-sized samples from one-quarter or
half-sized samples with the TMA.

During compaction, residue from the asphalt sample may bind to the
mold wall creating an uneven surface. These irregularities will
adversely affect the angle measurement of an internal measuring
device if its measurement probes contact the inner walls of the
mold. The TMA, however, measures the angle using the external
surface of the mold.

Model 3191 True Mold Angle Device 1

TWO-POINT MEASUREMENT METHOD

The TMA measures mold angle using a simple and traditional two­point measuring method. Troxler has used this concept to measure
mold angle since the company started manufacturing the original
Model 4140 Gyratory Compactor.

The two-point measurement uses a simple trigonometric function to
calculate gyratory compactor mold angle. Because the TMA is
secured to the frame of the compactor, the angle measu red is net of
frame deflection and therefore is the true mold angle. The result is
that the TMA gives precise and accurate true mold angle
measurements in a passive and independent manner.

The TMA method reasonably assumes that the mold wall is rigid
and non-deformable under normal compaction loads. The mold wall
is parallel to the centerline of the mold so that the measured angle is
concurrent with the cylindrical axis of the mold and specimen
during compaction.

Most importantly, the TMA is capable of isolating gyratory mold
angle from other compaction variables. End plate or platen
deflections and translations do not affect the measured angle.
Mixture surface deflections and temperature variations do not skew
the results. Therefore, compliance with AASHTO T312 §4.1 and

§9.5 is easily ascertained and, if necessary, corrections to gyratory
mold angles can be made reliably.

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