Updating Bituminous Stabilized Materials Guidelines Mix Design Report Phase II

The set-up of the test before trafficking commences, is a time consuming procedure. After the
specimens fastened into the steel beam, water is filled to a level in the bath 2mm above the
specimen’s surface. The water depth is kept steady by a weir at the end of the bath. The water
is pumped out of the weir and repeats the cycle all the time to maintain water level.
The water temperature during testing maintained at 25ºC using a thermally adjustable water
pump. The number of load repetitions at which profile measurements are taken differs according
to the type of BSM. Generally, more measurements are made early on during the test i.e. at
shorter intervals, because the rutting profile has an exponential relationship with time. However,
as shown in the following table, the number of load repetitions at which the MMLS3 test is
terminated, can vary significantly:
Table J.2: The number of load repetitions per measurement cycle wet condition
BSM Type
Loads per measurement cycle [No]
Initial (preliminary ) test
2% emulsion +1% cement
DNM 50 000 75 000 100 000
(long cured)
2% emulsion + 0% cement (G2) 0 500 900 Failure
2% emulsion + 1% cement (G2) 0 250 Failure -
2% foam + 0% cement (G2) 0 250 Failure -
Additional test
2% emulsion +1% cement (H-RAP) 0 45000 Failure
2% emulsion +1% lime (H-RAP) 0 45000 Failure
2% emulsion +0% cement (H-RAP) 0 2500 Failure
2% emulsion +0% cement (Q-G4) 0 2500 Failure
Failure = means ravelling –depth more than 12mm
After identification of the number of wet-trafficked axles to failure for a specific mix, the second
set of briquettes tested under dry condition to the same number of load application applied for
wet condition. Thereafter two sets specimens (dry and wet) could be tested in the ITS mode to
determine the tensile strength retained TSR i.e. wet over dry.
2.4 ITS Testing
Subsequent to trafficking, Indirect Tensile Strength (ITS) tests carried out on the specimens
removed from the MMLS3 test set-up. These tests results were then compared with ITS tests
performed on specimens not subjected to wet trafficking. In this way, a TSR result assessed for
the different BSM-mixes.
The Indirect Tensile Strength test performed using MTS equipment. The loading rate applied
during ITS test is 50.8mm/min. The Indirect Tensile Strength and tensile strength ratio of the
BSMs computed as follows, Equation 1 and 2:
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