Updating Bituminous Stabilized Materials Guidelines Mix Design Report Phase II

More documents

Recommendations

Info

H+0C-E01 H+0C-E06 H+0C-E07 Q+0C-E08 Q+0C-E06 Q+0C-E05 Q+0C-E04 AVERAGE Ravelling –depth [mm] 16 14 12 10 8 6 4 2 0 -2 0 500 1000 1500 2000 2500 3000 Cumulative no. of load application Figure J.20: Ravelling development of the BSM-emulsion mixes without active filler In contrast, BSM-emulsion with Hornfels-RAP and the addition of active filler provide a different insight into mix behaviour see Figure J.21. The BSM-emulsion of Hornfels-RAP with addition of 1% cement proves to be moisture resistant under wet trafficking. This mix shows little cohesion loss or stiffness reduction after 45000 load applications. While the BSM-emulsion of Hornfels- RAP with addition of 1% lime shows relative less resistance to moisture damage. The latter mix suffered severe reduction in cohesion and stiffness after 40000 load applications. H+1C-E02 H+1C-E06 AVERAGE H+1L-E08 H+1L-E05 H+1L-E03 H+1L-E02 AVERAGE 16 14 Ravelling –depth [mm] 12 10 8 6 4 2 0 0 -2 10000 20000 30000 40000 50000 Cumulative no. of load application Figure J.21: Ravelling development of the BSM-emulsion mixes with active filler 26
4.3 Saturation Level The moisture ingress (saturation level) in the BSMs depends on in particle interlock, particle type, binder content, and additions of active filler. The mixes with high void contents shows higher erosion due to high void pore pressure developed during wet trafficking. Figure 20 and 21 above exhibit that behaviour. Further observations on the results Figure 20 and 21 are that the BSM-emulsion with Hornfels-RAP plus 1% lime proves to be relative resistant to moisture damage up to a certain degree of saturation e.g. 80%. Thereafter severe cohesion loss and reduction of stiffness occurs resulted to exponential disintegration. Similar behaviour of BSMs with other aggregates plus 1% lime occurred on correlation test with MIST device testing system. MIST test results presented in separate report included in Task 9. 4.4 Testing temperature The testing temperature on this study was 25 o C, however field temperature in BSMs can vary significantly. The effect of wet heated testing might result in a significant damaging effect in terms of cohesion loss and stiffness reduction. However, moisture ingress and related damage in South Africa will take place during rainfall period, where the air temperature does not exceed 30 o C. Therefore, as BSMs used in base or subbase layer temperature will not exceed 25 0 C. During MMLS3 wet trafficking, the test temperature was controlled at 25 o C using thermocouples attached to the briquette at Position 3 and 6 of the briquette layout. The thermocouple reading was monitored intermittently during trafficking period. 4.5 ITS Testing After the MMLS3 tests, further conclusive evidence of the materials distress due wet trafficking could be observed upon removal of the trafficked briquettes and testing. The removal of briquettes included precaution to avoid further damage. Thereafter, ITS test was carried out to investigate the extent of distress on the BMSs due to wet trafficking performed. The quantification of the reduction of tensile strength was measured from the wet (trafficked) and dry (trafficked) briquettes. The Indirect Tensile Tests (ITS) was performed at the respective number of briquette recovered from MMLS3 test. At least three (3) specimens from every type of mix were tested. All ITS tests were performed at 25 0 C temperature. The ITS tests were done at controlled displacement with applied rate of 50.8mm/min. The results of the ITS tests are summarised in Table J.7, Table J.8 and Table 13Table 14. Tensile Strength Retained (TSR) after wet and dry MMLS3 trafficking can be calculated as a Ratio of average wet ITS over average dry ITS. The results of TSR presented in Table 15 above. 27
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: From Figure J.19 it can be seen tha
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 and 34: - No sign of significant initial de
Page 35: 5. BIBLIOGRAPHY ASPHALT ACADEMY. 20

Updating Bituminous Stabilized Materials Guidelines Mix Design Report Phase II

Create successful ePaper yourself

Delete template?

Save as template?