Project Summary: Performance Evaluation and Specification of Trackless Tack Page: Project Summary 0-6814
This pamphlet is part of the collection entitled: Texas State Publications and was provided to The Portal to Texas History by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
for concrete-surface samples. Compaction effort had
no significant effect on bond energy.
Concerning cracking resistance tests, the overlay test
was not sensitive to tack type, but the bending beam
fatigue tests were. Trackless tack samples lasted
more cycles than a sample with no tack. No samples
experienced temperature-related delamination.
Bond strengths from field samples were considerably
lower than for laboratory-compacted samples. US 96
had the highest bond strengths (60-95 psi), US 183
had low strengths (25-50 psi), and SH 336 had very
low strengths (15-30 psi). The range in bond
strength is related to different pavement surface
types, different HMA overlay designs, and different
compaction temperatures. In most cases tack rate did
not affect the bond strength.
What This Means
The researchers recommend adopting the DSR
tackiness test and track-free time test to qualifyN
-o
bO
ca4 . esidue
\;ed Sty .res;duel
SO - s.r
ot _
e5ldue
u1s n lSoftl
rn
E' mu 5;on
2 Etrackless tack materials. The researchers also
recommend adopting the shear bond strength test.
Draft test methods and a trackless tack material
specification are provided in the full report.
The laboratory results suggest that all the trackless
tack products can produce high bond strengths.
Several other factors, not just tack type, have an
equal or greater impact on overall bond strength. The
highest bond strengths are achieved between
overlays over new or milled HMA and when
compacting at higher temperatures. Overlay designs
with higher binder contents may also improve bond
strength. Tack application rates did not appear to
have a significant effect on bond strength.
This study did not consider long-term performance.
Tack type and application rate may be more
significant over time, mitigating moisture-related
damage and increasing bond strength through age
hardening.No0-acW
1
0
160
170
180
190
200
210
Reactivation Temperature ( F)
(Averge of surface and HMA temperature)
Figure 1. Bond Energy versus Trackless Tack Type and Reactivation Temperature.For More Information
Project Manager:
Darrin Jensen, TxDOT, (512) 416-4728
Research Supervisor:
Bryan Wilson, TTI, (979) 458-7989
Technical reports when published are available at
http:/library.ctr.utexas.edu.Research and Technology Implementation Office
Texas Department of Transportation
125 E. 11th Street
Austin, TX 78701-2483
www.txdot.gov
Keyword: ResearchThis research was performed ir cooperation with the Texas Department of Transportation and the Federal Highway Administration. The contents of this report
reflect the views of the authors, who are responsible for the facts and accuracy of the data presented here. The contents do not necessarily reflect the official
view or policies of FHWA or TxDOT. This report does not constitute a standard, specification, or regulation, nor is it intended for construction, bidding, or permit
purposes. Trade names were used solely for information and not for product endorsement.-10000- 1
Search Inside
This pamphlet can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Pamphlet.
Texas A & M Transportation Institute. Project Summary: Performance Evaluation and Specification of Trackless Tack, pamphlet, April 2016; Austin, Texas. (https://texashistory.unt.edu/ark:/67531/metapth903146/m1/2/: accessed April 18, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu; crediting UNT Libraries Government Documents Department.