PHASE II REPORT - Caltrans

Mix Torque kg-cm
70
60
50
40
30
20
10
0
European Mix Test
Mix
Spread
0 30 60 90 120 150 180 210 240 270 300 330 360
Time of Mixing (Seconds)
Figure 3.4: European Mixing Test Cohesion Parameters Versus Time
The test data would be evaluated by observing the mix parameters noted above as compared to
results from TB-113. In addition, the coating of the aggregate would be evaluated visually as is
currently done. This test would determine the preliminary range of mix proportions.
Starting from the European mixing test, the team purchased the equipment and carried out
series of tests to optimize the test for use in slurry seal design. The development and
evaluation of this test method is discussed in detail in Chapter 4.
3.6.3 The Automated Cohesion Test (ACT)
The next step in the mix design process is to determine the traffic time. This is a constructability
parameter, or a measure of the cohesion the mix must reach in order to accept traffic. This
level should be the same for any traffic type, but it may require different times at other
application conditions (e.g., temperature, time of day, anticipated rainfall).
The cohesion measurement is thus very important to ensure the mix will perform under traffic.
This property will be based on TB-139 to determine the mix and set traffic cohesion as well as a
24-hour cohesion. This may be measured under a range of conditions of humidity, temperature,
and ambient light to determine the suitability of mixtures for specific application conditions.
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