The research project will provide an overview of existing connecting joint systems and their practical experiences and their tests. A Ranking of the damage mechanisms and the decisive parameters and of the tests will be compiled and used as the basis for the following research projects: "Part 2: Behaviour of connecting joint systems using laboratory tests" (VSS 2007/402) and "Part 3: Behaviour of connecting joint systems in the practice” (VSS 2007/403).
The project has following phases:
- Development of implication of information and literature reviews
- Creating a questionnaire; poll
- Create a checklist; Property inspections / health scans
- Evaluating the results of the surveys and the property inspections
- Damage assessment and derivation of damage mechanisms and their decisive parameters
- Selection and defining the test methods
- Ranking and proposal of the most promising systems for follow-up projects
- Interim Financial Reporting at EK 4:07
- Submit proposals for the decision on the request of the follow-up research projects
Connecting joints for asphalt pavements are used on all types of roads. They occur in new roadways, but are especially common in mended areas following excavations. There are many different methods for creating connecting joints in asphalt pavements and it is often the preference of the building contractor that determines which system is used.
In this research project, an overview of existing connecting joint systems and practical experience of using them, as well as material and system tests, was compiled by researching the literature, conducting surveys with building authorities, construction companies and manufacturers/suppliers, and examining existing joints on site.
A ranking of the damage mechanisms and the parameters affecting them was compiled, along with an assessment of existing tests, and these serve as the basis for follow-up projects on connecting joint systems.
The examinations carried out on existing joints clearly demonstrate a problem of inadequately functioning joint systems and the resulting damage in asphalt pavements. Observations found that consistent weak points were connecting joint systems between stages and in mended areas. Cracks and surface eruptions originating from joints formed in the adjacent layers and pavement structures.
In practice, the two systems that clearly dominate are those using joint sealing tape and plastic masses. Joint sealing tapes are preferred for use in mended areas and plastic masses are preferred for larger asphalting tasks. When used correctly in conjunction with the correct geometry, these two systems result in good interaction of joints between two asphalt pavements. Other joint systems are assessed as ineffectual or are too complex and costly in their execution. For transitions from asphalt to concrete, the hot-poured joint has established itself as the standard. Experiences with filled joints between asphalt and concrete are judged to be entirely satisfactory.
The most important material properties are adhesion and viscoelasticity. The level of adhesion is a good indicator of the bond between the joint material and the adjacent asphalt layers. The degree of viscoelasticity provides insights into the behaviour of the material in different weather conditions. The other properties are not useful as indicators of the behaviour of the material in the connecting joint system. However, they may be meaningful for production monitoring within the factory.
Conclusions and recomme