In Austria, the longitudinal evenness of road pavements is currently assessed at project and network level using a variety of methods (planograph, 4 m straightedge, International Roughness Index [IRI]). These methods, however, provide only limited opportunities for accurately assessing road roughness in all its manifestations, such as periodic unevenness and individual discontinuities. This project started with a literature review of all methods currently used for measuring and rating longitudinal evenness. Subsequently, several of these methods were used for assessing 30 selected test sections (115 km in total) based on RoadSTAR longitudinal evenness meaurements. These test sections exhibited different structural characteristics and roughness problems typical of the Austrian road network. The results showed that none of the existing parameters is capable of comprehensively assessing roughness problems. Further investigations were thus carried out. Using a detailed heavy goods vehicle model (40 t semi-trailer truck), the dynamic wheel loads caused by uneven road sections were calculated for the 30 test sections based on the height profile. The aim was to derive information about road loading using three different models. While the curves resulting from the three models proved to be very similar in shape, the road loading values varied greatly depending on the model used. The models therefore did not provide clear and unambiguous information about the reduction in the pavement service life, which means that further research is required in this field. The weighted longitudinal profile (WLP) method, developed in Germany, was also investigated. The evaluation of the 30 test sections using the German parameters showed that although all phenomena of longitudinal evenness can be easily detected, it is not possible to optimally identify the extent of their effects. The rating function can, however, be adapted by varying the parameter "waviness". In order to adapt the WLP to Austrian conditions, the "existing" waviness of the entire Austrian motorway network was calculated and the German default setting was finally changed to w = 2.6. After this change in the setting, all relevant phenomena of longitudinal evenness (periodic or individual discontinuities, general unevenness) were adequately assessed. A rating scheme for the Austrian motorway network was subsequently developed and target, acceptance, warning and threshold values were proposed. The Austrian motorway network and all new motorway sections built in 2006 and 2007 were finally assessed using the adapted WLP (WLPAustria). The results showed that the new method is suitable for adequate assessment of longitudinal evenness and thus also as a parameter for pavement management and acceptance testing. Based on these positive results, it is intended to apply the WLPAustria in pavement management as well as acceptance and warranty inspections in the short term, although the results will not at first be relevant to construction contracts.
|Publikationsstatus||Veröffentlicht - 2009|
- Ehemaliges Research Field - Mobility Systems