Intelligent Compaction

This project aims to explore and facilitate the adoption of Intelligent Compaction (IC) technology in Queensland for earthworks and pavement materials.

This report presents a literature review of the use of intelligent compaction (IC). The aim of the review was to gain the experiences and understanding of recent advances in the use of IC technology for earth fill, granular and stabilised materials. A brief summary on the background and history of IC is presented, followed by an introduction of IC instrumentation systems. The benefits and disadvantages of IC are then discussed. The main advantages of IC technology are the improvement in compaction quality and uniformity, as well as the reduction in construction and maintenance costs, including the liability costs associated with repairs and maintenance after construction The report also presents details of current IC equipment, including both original IC rollers and the retrofit kit that can be incorporated onto conventional rollers. The adopted measurement values (MVs) used by different roller vendors are presented, with the emphasis on the theory behind these measurement values to correlate measurements to the soil stiffness/modulus. A summary of existing specifications adopted in Europe and the USA is also presented, which may serve as references for the development of Australian specifications on the use of IC. A series of findings derived from previous case studies on the correlations between roller measurement values and spot tests on different soil types and underlying materials is also provided. Based on the findings obtained from the case studies and the existing specifications, the general IC in situ calibration procedure is summarised, which may be adopted as a guideline to carry out an IC trial in Queensland. Finally, preliminary recommendations are made on how IC can be incorporated into current Department of Transport and Main Roads Technical Specifications, including MRTS04, MRTS05 and MRTS07B.

As compaction is critical for the performance of pavement layers, intelligent compaction (IC) is a solution to the rapidly growing need in the road construction industry for faster, more efficient and reliable ways of collecting compaction data, assessing the work during earthworks and pavement construction and giving immediate feedback and indicative information to the roller operator, supervisors, project managers and road engineers to make informed decisions. This NACOE project commenced in the 2018–19 financial year to facilitate the implementation of IC technology in Queensland. A comprehensive literature review was undertaken during the first year to evaluate the potential benefits of such technology for the Queensland Department of Transport and Main Roads (TMR) and the wider road construction industry. Year 2 (2019–20 FY) focused on the development of a pilot project-specific technical specification which was successfully trialled on the Ipswich Motorway Upgrade project where the IC technology was trialled on different materials. The study showed that the compaction meter value (CMV) has varying degrees of correlation against the in situ stiffness measured by light weight deflectometer (LWD) and conventional density results (measured by a nuclear density gauge). It was also noted that the CMV is sensitive to in situ moisture conditions during construction. The project funded the Veta program to support the latest GDA2020 system, which became the main cadastral grid to be used across different jurisdictions in Australia. In year 3 (2020–21 FY), the priority was to disseminate the knowledge and local experience on IC technology and promote its benefits. While monitoring the demonstration field trials, different levels of training were developed to share the knowledge and practical findings. To better illustrate the benefits of IC technology, a benefit-cost analysis was undertaken to cover the impact/difference of using IC. In the current financial year, the focus of the project was to trial the use of IC technology for asphalt layers. After gaining some experience on a few small projects, an asphalt rehabilitation project was chosen to be delivered as an intelligent compaction project. Pre-mapping was also practiced as it is seen as one of the major benefits of using IC technology for asphalt projects (in identifying weak support areas prior to the paving of the hot mix asphalt overlay). The work provided the opportunity to understand the requirements and details of how the road agencies can monitor, oversee, quality control and accept an asphalt project and what are the required area of work in terms of specifications, technical standards and contracts. Results also showed that for the asphalt layer, the intelligent compaction meter value (ICMV) is dependent

Intelligent compaction (IC) can provide important and immediate roller operating parameters to the operator (in the form of a visual map) to ensure that pavement layers and earthworks are compacted uniformly and in accordance with appropriate standards. IC data can also be uploaded and stored online for archiving and remote-monitoring purposes. Over the last decade, this technology has gained popularity around the world and has been shown to improve construction quality and productivity. This project commenced in the 2018–19 financial year to facilitate the implementation of IC technology in Queensland. A comprehensive literature review was undertaken during the first year to evaluate the potential benefits of such technology for the Queensland Department of Transport and Main Roads and the wider road construction industry. This report is a summary of the activities undertaken during year two (2019–20) . Year 2 focused on the development of a pilot project-specific technical specification for use in demonstration trials. The specification was successfully trialled on the Ipswich Motorway Upgrade Stage 1 (Rocklea to Darra) project. The IC technology was trialled on different materials compacted as part of the project including embankment fill, subgrade, cement modified base and unbound granular base. It was found that IC technology can readily identify soft areas in a pavement or embankment and can also be used to improve the uniformity of the compacted layers. The study showed that the Compaction Meter Value (CMV) has varying degrees of correlation against the in situ stiffness (measured by a light weight deflectometer) and conventional density results (measured by a nuclear density gauge). It was also noted that the CMV is sensitive to in situ moisture conditions during construction. It was realised early in the project that there will be significant learning required for the industry to become familiar with IC technology and to incorporate it into construction practices. Towards the end of this year’s project, the team delivered an online webinar to disseminate the results from the demonstration trial. AAPA also delivered a virtual masterclass, providing additional training on the use of the latest IC data management software, Veta 6.0. Finally, the project has funded Veta 6.0 to support the latest GDA2020 system which will soon be the main cadastral grid to be used across different jurisdictions in Australia.