PHASE II REPORT - Caltrans

Step 5: Evaluate the Cohesion Properties at Various Curing Conditions
The selected curing conditions should be representative of the project’s estimated humidity and
temperature conditions at the time of construction. CAT test is then performed at 30 minutes, 1
hour, and 3 hours.
Step 6: Evaluate the Long Term Properties of the Mixture
This step consists of evaluating the following:
• Abrasion: Using the CAT.
• Water Resistance: Using the CAT.
• Deformation (rut-filling mixes only): TB-109
Finally, any necessary adjustments and re-check of the mixing indices (spreadability, traffic, and
24 hour cohesion) will be made.
After selecting the best mix from the short-term test methods noted above, the mix will be tested
for the following long-term performance properties:
• Abrasion resistance
• Water resistance
• Deformation
Abrasion Resistance:
This property will be measured using the CAT test using fully cured specimens, soaked for 6
days, under project specific environmental conditions.
Water Resistance:
The CAT abrasion test will be run on the final mix design after being soaked for 6 days at a
temperature of 77°F (25°C) and comparing the loss to that of a 1-hour soak and express this as
a ratio. This information will be compared to the results of an existing mixture in order to
determine the appropriate specification limits. The test will then be checked with a mix of known
standard properties using other materials with which the team and advisory group have
experience.
Deformation:
This property will be measured using TB-147 “Test Methods for Measurement of Stability and
Resistance to Compaction, Vertical and Lateral Displacement of Multilayered Fine Aggregate
Cold Mixes”.
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