You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Correlation between the proposed and current methods:<br />
In the original hand mixing method per TB-113, the mix proportions were adjusted to determine<br />
mixing times relatively close to the minimum mix time requirements: 3 minutes for slurry seal<br />
systems and 2 minutes for micro-surfacing systems. When the minimum proportions were used<br />
for the AMT, as determined by using TB-113, predictably the mixes would be changing much<br />
more quickly and recorded as such during the AMT evaluation.<br />
In both test methods (proposed and current), when there were more total liquids in the systems,<br />
the viscosities were lower. In both test methods, mix systems with higher total liquids will<br />
deliver very extended mixing times.<br />
Suitability of the proposed test method:<br />
The equipment as developed still requires that the operator has a certain level of experience in<br />
order to set up and run the test in a short period of time.<br />
As developed, the equipment needs to be modified to accurately control mixing temperatures<br />
other than 77°F (25°C) and mixing humidity above 50%.<br />
Another challenge is the operation of the IKA software. This software was originally developed<br />
for use with multiple mixers, mediums and applications.<br />
Additional research needed for this test method:<br />
All the mixes used during the evaluation of the AMT were mixes where the aggregate was larger<br />
than a Type 2 aggregate. More evaluations should be performed on different aggregate sizes.<br />
The test method does require that the laboratory technician have experience in preparing the<br />
mix and setting the mixture into the testing equipment. Somehow making that process<br />
mechanical would decrease the amount of experience a technician is required to have to<br />
perform the AMT method and decrease the amount of error when the stirrer is not properly<br />
placed into the mixture.<br />
An environmental chamber that won’t affect the motor of the mixer or the shaft of the mixing tool<br />
needs to be developed for evaluating mix systems for temperatures at 59°F (15°C) or 95°<br />
(35°C) and at higher humidity conditions.<br />
Developing a specific software program for slurry system applications as it relates to the AMT<br />
method would make the test method easier to use from one laboratory to another.<br />
71
Change language