1 / 20

Slurrybound Macadam as Surfacing Option

Slurrybound Macadam as Surfacing Option. Johan Hattingh. May 2005. Index. Introduction Overview on the recent development of the Macadam Technology Research Work 3.1 Laboratory test 3.2 Improved construction techniques Conclusion. 1. Introduction. Report back on research work

tareq
Download Presentation

Slurrybound Macadam as Surfacing Option

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Slurrybound Macadam as Surfacing Option Johan Hattingh May 2005

  2. Index Introduction Overview on the recent development of the Macadam Technology Research Work3.1 Laboratory test3.2 Improved construction techniques Conclusion

  3. 1. Introduction • Report back on research work • To date limited to layerworks • Existing laboratory tests not suitable for the slurrybound macadam surfacing option • Design and specifications more a ‘mog dit troffe’ approach • Riding quality / Equipment

  4. Brief overview on recent development of the Macadam Technology Theme: From base technology using ballast / coarse aggregate to surface technologies • Slurry armoring on WB-base. Seaslope Interchange. (Roux / Otto – CSIR)(Early 90’s)

  5. Filler sand substituted by bituminious slurry.Thick slurrybound Macadam layers using railway ballast.Baragwanath Hospital (Potgieter, Hattingh).Bus bays in Mohlakeng (1993).

  6. Slurrybound Macadam with reduced bitumen content in penetration slurry 37mm stone mix (Doornkop Soweto).(1994).

  7. Composite Macadam (37mm stone bottom / 26mm top with rich slurry)>200km street network constructed.Masabeni Street, Springs / Attridgeville / Mamelodi / Kagiso / New Brighton etc.SABITA-award, 1995.

  8. 50mm Slurrybound Macadam (26mm stone size)Mamelodi / Attridgeville / Kagiso > 200km. (1995 – 1997). • 15mm – 25mm thick Slurrybound Macadam> 200km.Leroro / Kagiso / Mamelodi

  9. Overlay applications with varying thicknesses.Marakele National Park / Makapan Tower Road / Kagiso

  10. Introduction of the spinning beam on guiderailsSoweto(2004)

  11. Research work 3.1 LABORATORY Current tests all base (layerwork) related: Materials: Grading, ALV, PI, etc. Density: Rondavel tests Strength parameters: CPA-method / Stability / Binder Content on slurry only Challenges: - Densification of the Marshall briquette - Penetration of the slurry without disturbing the stone skeleton - The use of a bitumen emulsion in the preparation of the briquette (CPA-method: Emulsion substituted by pen-grade binder)

  12. Proposed revised briquette preparation: • Mount a Proctor-mould to a vibratory table. • Fill the mould with the coarse aggregate to half 32mm. • Place the Marshall hammer as loose weight on the coarse aggregate and vibrate (using the table) for 60 seconds. • Wet the aggregate using either water or a bitumen-emulsion1 • Mix the slurry to specified consistency using the flow-plate2 • Place the determined 3 volume slurry on top of the coarse aggregate with the Marshall hammer as loose weight on top and allow the table to vibrate for 60 seconds. • Repeat the above to achieve 60mm briquette thickness. • Cure the briquette in the mould before stripping. • Densify briquettes (30 blows) with Marshall hammer after preheating. • Briquettes ready for further Marshall tests. 1Deduct volume used from optimum emulsion content. 2Optimum slurry mix and consistency is a separate exercise. 3Determined in terms of volumetric principles through experimentation

  13. Wet aggregate 1 layer 1% Cement 8% net Binder slurry flowable* Wet aggregate 1 layer 1% Cement 8% net Binder slurry flowable* Wet aggregate 1 layer 1% Cement 8% net Binder slurry flowable* * Compaction: Vibrated without surgarge weight then level and vibrated with surgarge weight

  14. Test results on SB-briquettes

  15. 3.2 IMPROVED CONSTRUCTION TECHNIQUES

  16. 3.2 IMPROVED CONSTRUCTION TECHNIQUES (continued)

  17. 3.2 IMPROVED CONSTRUCTION TECHNIQUES (continued)

  18. 4. Conclusion • Research, design and specifications now scientific using Marshall principles • High quality construction with improve riding quality • Workforce at least three times higher than conventional

  19. 5 point scale

  20. ANALYSIS OF ROAD ACTIVITES AGAINST COSTS, TIME, QUALITY SUITABILITY, LABOUR COMPONENT AND APPLICATION

More Related