Road Monitoring and Assessment
Development of new evaluation and assessment methods of substance characteristics (surface) for the monitoring and assessment (ZEB) of federal trunk roads - concrete pavements (04.0315)
Within the road monitoring and assessment (ZEB), the substance characteristics (surface) of the road surface are, among other things, recorded by in regular traffic operating measurement vehicles using cameras and subsequently evalueted manually. The results obtained in this way provide initial indications of structural damage to the carriageway. The existing list of damage characteristics in the regulations is now about 25 years old and needs to be reviewed on the basis of current structural engineering knowledge in concrete construction. Overall, it is crucial that those damages are detected that trigger a need for maintenance and that a delimitation of the damages takes place with regard to the need for maintenance that is considered to be directly caused by them or necessary in the further development. Against this background, the causes of occurring damage in concrete pavements are to be considered. The aim of the research project is to optimize the evaluation and assessment methods of substance characteristics (surface) for the ZEB of federal trunk roads in the concrete construction method, so that they meet the requirements for positional accuracy resulting from the new value synthesis valid since 2015, as well as the quantitative description and differentiation of the damage characteristics. For the developed method, clear and simple coding rules have to be formulated, which can be used both for a manual evaluation and for an evaluation based on AI (neural networks). The ultimate goal is an increase in data quality based on an optimized evaluation and assessment process.
Network-wide early detection of AKR-damaged concrete road pavements with high-speed measuring systems (04.0310)
Within the condition recording and evaluation (ZEB), the substance characteristics (surface) of the road surfaces are recorded by measuring vehicles using high-speed imaging methods. During the subsequent surface image evaluation, no independent characteristic to be coded is currently defined for damage caused by the so-called alkali silica reactions (ASR) in concrete construction. Experience shows that the damage process of the ASR is influenced by many boundary conditions and that the degree of damage progresses differently. The planning of a structural maintenance measure in the case of a proven ASR is unavoidable. Early detection offers possibilities for time planning. If necessary, measures can be taken to slow down the damage process. Within the framework of the project, the possibilities for early detection of a concrete roadway damaged by ASR are therefore to be investigated. The focus here will be on the requirements for network-wide and fast-moving detection. When designing the concept, care must be taken to ensure that it can be integrated into the ZEB's current standardised procedure.
Cooperation between Rijkswaterstaat and BASt on SKM measurements (3116001)
Rijkswaterstaat (RWS) is in a project of changing its present Dutch national skid resistance standard to the German SKM-standard. ln contrast to the present situation, after the transition RWS will no Ionger secure the quality of the skid standard in the Netherlands and will not have and operate skid devices to conduct checks on measurements executed by contractors. Although RWS will adopt the SKM-standard it is recognized that, in particular due to the application of porous asphalt surface layers on RWS-network, not all German SKM-prameters may apply. Therfore RWS will conduct research in this topic.
Extending the Use of the Weighted Longitudinal Profile to Construction-Related Applications and its Comparison with Existing Acceptance Procedures (04.0286)
The Weighted Longitudinal Profile (WLP) is described in the document TP Even – Contactless Measurements. Previous research projects have already established its usefulness for purposes of road condition documentation and assessment (ZEB) and established an appropriate assessment basis for it. The procedure has now been incorporated into European standardisation and therefore confirmed in principle. As a result of earlier target objectives, the WLP assessment was only applied to 100 or 20 metre-long sections of road respectively. In the context of construction-related applications, however, it is the case that the creation of single 100 or 20 metre-long measurements is not expedient. In such cases, there are actually no validated approaches providing for the precise measurement of the longitudinal evenness of a road. In particular, there is no precise universal standard governing the way in which the frequency of tolerance violations is to be documented in a test report. The lack of studies regarding the compatibility of existing contact or non-contact acceptance procedures and the WLP are currently preventing this procedure from being introduced as an acceptance procedure. This research project therefore seeks to close these gaps and to pave the way for opening up the acceptance procedure to non-contact measurement procedures.