Sealed road

Abstract: Guide to Pavement Technology Part 2: Pavement Structural Design provides advice for the structural design of sealed road pavements. The advice has been generally developed from the approaches followed by the Austroads member agencies. However, as it encompasses the wide range of materials and conditions found in Australia and New Zealand, some parts are broadly based. This Part covers the assessment of input parameters needed for design, design methods for flexible and rigid pavements and gives guidance on the economic comparisons of alternative pavement designs. AustPADS Austroads' pavement design software, AustPADS conducts advanced mechanistic analysis of the response-to-load of road pavements. The AustPADS user interface and the underlying analysis engine APADS were developed by ARRB Group for Austroads. The analysis engine is based upon a finite element method model and software developed by Dr Markus Oeser. The primary users for AustPADS are Australia and New Zealand road managers, industry organisations and consultancies working with road agencies. Access may not be granted to other users. If you are considering conducting training using AustPADS please contact austroads@austroads.com.au and supply information about who is conducting the training, when and where the course will be held, when the software is likely to be accessed and how many participants you are expecting. This 47 minute video provides an overview of AustPADS and includes design and analysis examples.

Abstract: A mobile (truck-mounted) imaging system uses laser-based technology to obtain accurate quantitative data in real time and at high speeds regarding the conditions of road and highway surfaces. Specifically, the GIE Technologies laser vision system integrates a three-dimensional laser-sensing imaging sensor array to map the cracks, ruts and roughness of road surfaces. The LaserVision System simultaneously records a three-dimensional information along with photometric data using the same set of Biris (bi-iris) sensors. These sensors were developed for this application by engineers at GIE Technologies Inc. under exclusive license from the National Research Council (Ottawa, Canada). They rely on a combination of defocusing and triangulation principles to record 3D information about a test surface. The Biris approach, for a mobile pavement testing system, offers several performance advantages in comparison to other sensing methods. Most important, a Biris sensor uses all- solid-state components with no moving parts. This rugged design is highly resistant to misalignment and performs well in a moving, continuously vibrating vehicle. The photometric (intensity) information provides complementary data where ranging alone proves insufficient, as when detecting pavement markings, sealed road cracks or patches. In addition, the range analysis uses simple trigonometry to obtain real-time performance.

Abstract: Knowledge of pavement technology is of critical importance for all transport agencies in Australia and New Zealand. Austroads and others (e.g. state road authorities, local government, and industry) have amassed a great deal of knowledge on pavement technologies, techniques, and considerations. The purpose of the Austroads Guide to Pavement Technology is to assemble this knowledge into a single authoritative publication that is a readily available, accessible and comprehensive resource for practitioners in Australia and New Zealand. This part provides advice for the investigation of existing sealed road pavements and the selection and design of pavement strategies/treatments. The advice has been generally developed from the approaches followed by Austroads member authorities. However, as it encompasses the wide range of materials and conditions found in Australia and New Zealand, some parts are broadly based. Treatment selection is related to availability of materials and knowledge of their performance in any particular locality. Part 5 covers pavement investigation, testing and evaluation, identification of causes and modes of distress and description of treatment options.

Abstract: A survey of U.S. public highway and road agencies that use chip seals as a part of their roadway maintenance program was developed and conducted as a part of NCHRP Synthesis of Highway Practice 342. Ninety-two individual responses from across the United States, Canada, and overseas were received. This paper seeks to correlate individual chip seal performance ratings with the construction practices reported to achieve those ratings. It finds a number of strong correlations. The most important is that the ambient air temperature specification is generally higher [average of 60°F (15°C)] for those respondents reporting excellent or good chip seal performance. The same trend was observed with the average amount of time before full-speed traffic was allowed to traverse a newly sealed road, with the best performing seals having an average wait period 28 h. Finally, respondents reporting the best performing seals used more preseal preparation measures and more detailed traffic control measures. The same responde...