6 minute read
AAPA Article
THE AUSTRALIAN ASPHALT PAVEMENT ASSOCIATION’S EXECUTIVE DIRECTOR OF TECHNOLOGY AND LEADERSHIP, ANNA D’ANGELO, EXPLAINS THE BENEFITS OF INTELLIGENT COMPACTION AND THE IMPORTANCE OF USING THE TECHNOLOGY TO PRODUCE QUALITY PAVEMENTS.
The Australian flexible pavement industry is committed to continual improvement of flexible pavement construction outcomes.
The peak body for the industry, Australian Asphalt Pavement Association (AAPA) supports the use of innovative and smart technology to improve the quality and consistency of the delivered product. One such example of an innovative technology is the Intelligent Compaction system.
Over the past few decades, Intelligent Compaction systems have been developed to enable increased quality when applied to asphalt compaction.
Internationally, the use of Intelligent Compaction technology in pavement construction is growing and 33 American states have implemented Intelligent Compaction specifications for asphalt paving. BENEFITS OF INTELLIGENT COMPACTION Intelligent Compaction refers to the compaction of road materials using modern vibratory rollers that are equipped with an in-situ measurement system and feedback control.
For asphalt, this includes the use of vibratory rollers with an integrated response measurement system, a global positioning system, a software that automates documentation of the results and on-board computer display.
This can be combined with infrared temperature sensors to track the surface temperature.
There are several well documented benefits of Intelligent Compaction for asphalt. Firstly, it can improve uniformity and density which leads to quality asphalt performance. Secondly, it can also lead to improved efficiency during the compaction process.
In addition, Intelligent Compaction can improve documentation of the compaction process providing improved process control records and has the potential to reduce compliance testing.
AAPA recognises this technology can offer the opportunity to achieve lower construction costs with increased pavement durability and saw a need to further develop industry knowledge of the fundamental concepts of Intelligent Compaction.
To address this need, AAPA organised its first Virtual Master Class bringing international experts from the USA to offer access to their knowledge and experience.
For the Virtual Master Class, an interactive forum linked to experts such as George Chang, from Transtec, Prof. Nazarian from the University of Texas and Rebecca Embacher from Minnesota Department of Transport.
These industry experts provided an
update on the recent developments of the technology and shared their journeys in the implementation of Intelligent Compaction.
Dr. Jeffrey Lee from ARRB also shared an update on the National Asset Centre of Excellence (NACOE) research project, carried out to facilitate the implementation of Intelligent Compaction in Queensland.
Hands on training was facilitated through the masterclass. This included training on the Veta software, which is one of the data management and analysis platforms for Intelligent Compaction. This is an essential part of the system allowing the user to import data from various Intelligent Compaction machines. This way the user can perform viewing, filtering, spot test imports, and analysis.
Veta 6 is the latest software release with comprehensive viewing and analysis capabilities for intelligent construction data that provides additional features to previous versions.
The association will continue to offer training to agencies and industry personnel on how to practically use and implement the technology as well as to manage and analyse the data collected.
BACKGROUND Compaction is one of the most important processes in roadway construction. It can be used to achieve high quality and uniformity of pavement materials to ensure durability. Achieving uniformity is the key for successful compaction.
Traditionally a random distribution of in-situ spot tests or core tests are performed but these may not provide a full representation of the pavement area and may not be able to identify weak areas. Consequently, this may lead to variable or unsatisfactory compaction causing premature failure and reduced life performance.
The integration of measurement, documentation, and control systems for Intelligent Compaction allows realtime monitoring and correction of the compaction process. These systems are available from major compaction equipment suppliers and can also be retrofitted to existing rollers.
Intelligent Compaction rollers can continuously record the number of roller passes, roller-integrated Intelligent USING INTELLIGENT COMPACTION, CONTRACTORS AND ROAD AGENCIES CAN MEASURE REAL-TIME MATERIAL PROPERTIES DURING COMPACTION AND REPORT EVERYTHING FROM THE FIELD. PRE-MAPPING THE EXISTING SUPPORT LAYERS PRIOR TO ASPHALT PAVING CAN ALSO HELP IDENTIFY ANY SOFT SPOTS. IT ALLOWS USERS TO MAKE CORRECTIVE ACTIONS PRIOR TO ASPHALT CONSTRUCTION, ADDRESSING ANY POTENTIAL ISSUES EARLIER.
Compaction Measurement Value (ICMV), GPS locations of the roller, roller vibration amplitudes or frequencies, and asphalt surface temperatures, providing full coverage of the compacted area.
ICMV is a term for a value which is calculated using different models and methods, based on the vertical acceleration at the centre of the vibrating roller drum.
When the roller drum applies compaction force on the material it will receive a rebound force from the compacted material. This reacted force is captured by the accelerometer and it is processed by the computer system that calculates the ICMV.
Extensive research has been done since the 1980s to generate and calibrate input to various ICMVs to measure mechanical and physical properties such as stiffness, modulus, and density of compacted layers and allow true real-time feedback system control.
This combination of construction equipment technology and data reporting helps to ensure optimum compaction and uniformity is achieved through continuous monitoring of operations. This process works to reduce compaction effort, improve sustainability, increase the durability of the pavement and reduce construction variability.
Using Intelligent Compaction, contractors and road agencies can measure real-time material properties during compaction and report everything from the field. Premapping the existing support layers prior to asphalt paving can also help identify any soft spots. It allows users to make corrective actions prior to asphalt construction, addressing any potential issues earlier.
One of the challenges AAPA has seen, that has affected the implementation of Intelligent Compaction in USA, was the incompatibility of data between systems.
Roller equipment from various suppliers measured and reported different parameters making it challenging to compare compaction outcomes between equipment from different brands.
In the USA a single data standard is now applied, as defined in AASHTO Designation PP 81-18 Intelligent Compaction Technology for Embankment and Asphalt Pavement Applications. The equipment from all major suppliers can provide data to comply with this standard.
AASHTO PP81-18 also requires the Veta software for data management and geospatial analysis of intelligent compaction and temperature sensing results.
WHERE TO NEXT The use of Intelligent Compaction offers the opportunity to improve the effectiveness of the compaction process, achieve uniform compaction and can enable 100 per cent coverage of the asphalt construction work.
In addition, the large amount of data collected during the process can be evaluated and used for pavement management improvements.
AAPA has seen the USA develop Intelligent Compaction specifications that provide information on the system requirements, quality control requirements, training, data requirements and submission, and measures and payment.
In Queensland the Department of Transport and Main Roads has drafted Intelligent Compaction specifications for soil and asphalt and demonstration trials are scheduled to use Intelligent Compaction for asphalt quality purposes.
AAPA is collaborating with research bodies, universities, state road authorities and industry members to facilitate the implementation of Intelligent Compaction of asphalt in Australia.
The association says this has the potential to improve flexible pavement construction outcomes and at the same time reduce construction costs.
