Effectiveness of Bitumen Emulsion as a Stabilisation Agent in Recycled Sealed Rural Roads

Baker, Kurt (2017) Effectiveness of Bitumen Emulsion as a Stabilisation Agent in Recycled Sealed Rural Roads. [USQ Project]


Over the past decade local road authorities have seen an increase in the deformation experienced in rural areas, due to an ageing road network combined with adverse climatic conditions, poor drainage and an increase in road use. It is becoming increasingly important to find a more efficient form of pavement rehabilitation to reinstate these failing roads by extending the design life. One method that is largely untested in the Toowoomba Region is bitumen emulsion stabilisation.

The key purpose of this investigation is to analyse the effectiveness of bitumen emulsion as a stabilisation agent in a rural road application. In order to determine the suitability, a number of tests are to be undertaken. After reviewing a number of design manuals, a testing regime was determined with acceptable limits for test results.

Sample material from the Toowoomba Regional Council Gap Road Infrastructure Enabling Project was tested for unconfined compressive strength, Californian bearing ratio and capillary rise testing. Cationic bitumen emulsion was used at 2%, 3%, 4% and 5% residual bitumen contents in specimens. The modulus of the emulsion treated specimens was compared to control material to determine if there was an increase in the pavements performance.

Preliminary testing was conducted to determine if the Gap Road sample material fit within the guidelines for testing. The sample material does not fit within the acceptable grading curves of the analysed guidelines, however testing continued to determine if a typically marginal material could be benefited by bitumen emulsion treatment.

After analysis of the results it was established that bitumen emulsion stabilisation offered a number of benefits over the control material. Unconfined compressive strength results illustrated that there was a definitive optimum bitumen content for the Gap Road sample material. Elastic modulus calculations determined that bitumen emulsion provides a greater strength then the control material. Capillary rise testing showed that specimens treated with bitumen emulsion showed no discernible volume change or movement of water after 72 hours. A cost benefit analysis determined that an 81% reduction in pavement thickness could be expected by the incorporation of bitumen emulsion into the bridging layer of the Gap Road pavement.

The conclusion made from the results of the investigation were that the Gap Road sample material would greatly benefit from bitumen emulsion stabilisation. An increase in the resilient modulus and a reduction in the moisture sensitivity would be expected from treatment.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours) (Civil)
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Somasundaraswaran, Soma
Date Deposited: 07 Sep 2022 05:14
Last Modified: 07 Sep 2022 05:14
Uncontrolled Keywords: bitumen emulsion; stabilisation agent; recycled; rural roads
URI: https://sear.unisq.edu.au/id/eprint/40872

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