Updating Bituminous Stabilized Materials Guidelines Mix Design Report Phase II

Figure J.22 illustrates the comparison of the strength reduction of BSMs from dry trafficking to
wet trafficking conditions. The wet trafficking ITS shows a decrease in strength from dry
trafficking ITS. However the comparison of the ITS values shows no significant difference for
most of the BSMs tested, with some exceptions i.e. BSM-emulsion with Quartzites. This indicates
that ITS test is not particularly sensitive to moisture effects.
From previous analysis, see Section 4.1, the resistance to disintegration and ravelling by a long
cured BSM-emulsion, indicated high moisture resistance. However, looking at the ITS values, the
difference between highly moisture resistant to highly moisture susceptible BSMs is insignificant.
This confirm the weakness of the ITS test, as reported previously by Hodgkinson, (2004). The
lack of reliability and repeatability of the ITS test for use in ranking BSMs in terms of moisture
susceptibility, should preclude its use for important applications of BSMs.
ITS [kPa]
400
350
300
250
200
150
100
50
0
H+1C-E01 (long cured
G2+0C-E02
G2+1C-E01
G2+0C-F01
H+0C-E01
BSM-Mixes
Q+0C-E04
H+1C-E02
H+1L-E02
Wet Trafficked ITS
Dry Trafficked ITS
Figure J.22: Comparison of ITS results after wet and dry MMLS3
trafficking on different BSMs
Further, comparison of the ITS values shows an increase in the moisture-sensitivity of the BSMs
from initial study to additional study. However, it should be noted that in the initial study, wet
trafficking terminated at 250 and 900 load applications after ravelling depth of 2mm to 4mm,
while in the additional study, wet trafficking terminated at a 2500 and 45000 load application
after ravelling-depth of 4mm to 12-14mm.
Ravelling-depth of 4mm under the MMLS3 appears to be critical, see Figure J.20 and Figure
J.21. At 4mm of ravelling BSMs experiences severe cohesion loss of stiffness reduction.
Thereafter exponential disintegration occurs. It is appropriate to extend testing beyond 4mm of
ravelling during moisture susceptibility testing with the MMLS3 trafficking.
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