Updating Bituminous Stabilized Materials Guidelines Mix Design Report Phase II

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- 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. 34
5. BIBLIOGRAPHY ASPHALT ACADEMY. 2002. The design and use of foamed bitumen treated materials. Interim Technical Guideline TG2, Pretoria, South Africa. AKZO NOBEL CHEMICAL, 1997. Bitumen emulsifier, Technical paper presented in 24 th AEMA meeting, Cancun, Mexico. BRENNEN M., TIA M., ALTSCHAEFFL A.G. AND WOO L.E. 1983. des Laboratory investigation of the use of foamed asphalt for recycled bituminous pavements. Asphalt materials, mixtures, construction, moisture effects and sulphur. WASHINGTON, DC: Transportation Research Board CASTEDO – FRANCO L.H., BEAUDOIN C.C., WOOD E.L AND ALTSCHAFFL A.G 1984. Durability characteristics of foamed asphalt mixtures. Proceedings of the 29 th Annual Canadian Technical Asphalt Association Conference, Montreal, Canada. HODGKINSON A. AND VISSER AT,. 2004. Investigation In to The Role Of Cementitious Binders When Recycling With Foamed Bitumen Or Bitumen Emulsion. Conference on Asphalt Pavements for Southern Africa, Victoria Falls, Zimbabwe. JENKINS J.K., 2000. Mix design considerations for cold and half-warm bituminous mixes with emphasis on foamed bitumen. PhD Dissertation, University of Stellenbosch, South Africa. LIEBENBERG J.J.E., 2003. A structural design procedure for emulsion treated pavement layers. Masters Dissertation, University of Pretoria, South Africa. LONG, FM.2002. The development of structural design models for foamed bitumen treated pavement layers. Pretoria: Transportek, CSIR. MALUBILA, S. M., 2005. Curing of foamed bitumen mixes. M.Eng thesis University of Stellenbosch, South Africa SABITA. 1993. GEMS- The design and use of granular emulsion mixes. Manual 14, Cape Town, South Africa SOUTH AFRICAN BUREAU OF STANDARDS, 1972. Standard specification for anionic bitumen road emulsion. Second revision. SABC 309-1972. WALUBITA, L. F., HUGO, F., EPPS-MARTIN, A. L., 2002. Indirect tensile fatigue performance of asphalt after MMLS trafficking under different environmental conditions. Journal of the SA Institution of Civil Engineering, Vol. 44, Number 3. Johannesburg, South Africa WIRTGEN, 2004. The Cold Recycling Manual, 2 nd Edition, Windhagen, Germany. 35
Page 1 and 2: APPENDIX J Technical Memorandum Upd
Page 3 and 4: findings of the moisture damage tha
Page 5 and 6: Figure J.4: The measuring wheel of
Page 7 and 8: An electric calibration unit used t
Page 9 and 10: 2.2 BSMs for MMLS3 testing The inte
Page 11 and 12: Figure J.12: The side view of the b
Page 13 and 14: The set-up of the test before traff
Page 15 and 16: 3. TEST RESULTS The use of vinite o
Page 17 and 18: Table J.7: ITS results after wet an
Page 19 and 20: Table 11: Ravelling-depth after MML
Page 21 and 22: Table 15: Tensile Strength Retained
Page 23 and 24: The comparison of BSMs on Figure J.
Page 25 and 26: From Figure J.19 it can be seen tha
Page 27 and 28: 4.3 Saturation Level The moisture i
Page 29 and 30: Ravelling-Depth [mm 16 14 12 10 8 6
Page 31 and 32: From the study conducted in MIST de
Page 33: - No sign of significant initial de

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