Identifying best practice pavement design for an unsealed road network to achieve sustainability improvements

Smith, Benjamin James (2016) Identifying best practice pavement design for an unsealed road network to achieve sustainability improvements. [USQ Project]

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The construction and maintenance of unsealed roads is a major responsibility of local and state governments, essential for the safe and efficient movement of people and goods.

Transport efficiency within south-western Queensland is of state and national significance given the importance of the industries residing within it and attracted to it; namely oil and gas, agriculture, and tourism. This efficiency is facilitated by high quality road surfaces which are fit for the purpose designated them by the road user and the road authority. The purpose of this
project is to conduct a review of current road construction and maintenance practices, guidelines and specifications, and to identify, with assistance from documented sources of knowledge, the material properties and pavement constituents which provide the most resilient unsealed pavement wearing course.

Current maintenance practices were assessed, indicating a lack of technical knowledge of local materials and a subsequent inability to support their use for road building applications. The majority of road network in the Maranoa Regional Council is unsealed. Therefore, the literature review focussed on the quality assurance measures utilised in industry as benchmarks to recognise the road building capabilities of potential materials for unsealed road construction and rehabilitation.

The project aimed to provide important technical information regarding the mechanical properties of locally produced road building materials, including the material qualities of both standalone and granular stabilised gravel products and the feasibility of stabilisation techniques employed; to identify reasonable solution pathways to improve the Maranoa Regional Council’ and South-West districts’ road building processes.

The study focussed on the South West statistical district of the Department of Transport and Main Roads and the Maranoa Regional Council and the concepts shown may be investigated and applied to other state and local government authorities. Firstly, the material properties of locally sourced gravels were evaluated using material property standards and guidelines used within the national road building industry. Once the individual gravel material properties had been identified, a design aid, in the form of a spreadsheet, was developed to evaluate a series of potential granular blends using combinations of the standalone sources.

The results of this study found 31 standalone gravel products, from which a further 17 were developed by blending, found suitable for unsealed road construction, pursuant to further testing. Further feasibility analysis will provide more conclusive economic indication as to the likely geographical locations suitable for implementation of the blends determined herein.

The processes used in this investigation, and in particular the pavement blending spreadsheet may be further developed to include logistical and economic parameters to allow for optimised material selection for the construction and maintenance of a good quality local road network.

This paper revisits current best practices for unsealed roads and presents optimised pavement blends for use on the road networks in focus, allowing practitioners to maximise the reuse of available in-situ material and low cost borrow pit material.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours) Major Civil Engineering project
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Thorpe, David
Date Deposited: 23 Jul 2017 23:24
Last Modified: 23 Jul 2017 23:24
Uncontrolled Keywords: road construction; gravel; Maranoa; best practice pavement design, unsealed road network, sustainability improvements
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090502 Construction Engineering
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400504 Construction engineering

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