Updating Bituminous Stabilized Materials Guidelines Mix Design Report Phase II

- The relationship between Tensile Strength Retained (TSR), Ravelling-depth (RvD) and
Retained Cohesion (RC) highlights the empirical nature of the TSR in measuring moisture
related resistance of BSMs, as it is inconsistent with the other results. Reasonable
comparison is obtained from MMLS3 tests and triaxial tests in terms of moisture
sensitivity of BSMs.
4.5 Recommendations
- The used of APT Device (MMLS3) has shown potential in identification of BSM-Mixes
distress under wet trafficking. It can therefore recommend being adapted for testing
Bituminous Stabilised Materials (BSMs).
- The use of vinite or reinforced rubber mat in the wet MMLS3 trafficking, proves to
minimise the direct abrasion of wheel to the specimen. The flexibility of the vinite layer
does not distribute stress to the briquettes, while maintaining the pore pressure induction
during wheel trafficking. Therefore, recommended for use in MMLS3 testing, for possible
ranking of the BSMs in moisture susceptibility.
- The new testing variables applied during MMLS3 testing i.e. 420kPa, 1.8kN and
7200wheel per hour found to validate results obtained with MIST device testing system.
Therefore, recommended for use in both APT device (MMLS3) and MIST device.
- The influence of additional of active filler in the BSM-Mixes is vital for the improvement in
moisture susceptibility. Therefore, addition of 1% cement recommended in BSMs,
however depending on the severity of saturation level, the use of 1% lime would provide
sustainable moisture resistance similar to addition of cement.
- Ravelling-depth of 4mm under the MMLS3 wet trafficking appears to be critical. It is
recommended to extend testing beyond 4mm for better screening the BSMs.
- 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.
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