Entwicklung von PU-Asphalt : von der Idee bis zur baupraktischen Umsetzung
- Development of PU-asphalt : from the concept to the practical implementation
Renken, Lukas; Oeser, Markus (Thesis advisor); Wistuba, Michael (Thesis advisor)
Aachen (2019, 2020)
Dissertation / PhD Thesis
Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2019
Permeable pavements provide new opportunities to unseal transportation infrastructure and to improve the urban climate. Because of limited durability, conventional materials for permeable pavements are used only selectively in urban areas. Thus, the development of innovative infrastructure materials for durable permeable pavements are required. A full substitution of bitumen by an innovative synthetic binder was restrictively applied within road-construction engineering so far, although the performance potential as well as the characteristic versatility are very high. Particularly, regarding the considerate exploitation of raw materials, polyurethane (PU) can be used as an alternative to bitumen. The main objective of this thesis is to develop a completely novel porous material concept "PU-asphalt" based on the synthetic binder polyurethane, including the material characterisation and the practical implementation. In this context it could be identified that polyurethane, for which production is mainly based on renewable raw materials, is appropriate to replace conventional bitumen. The created pavement material PU-asphalt presents high porosity with high material strength and low sensitivity of temperature at once. A concept of material investigation was developed which allows a comprehensive characterisation. Subsequently, the main characteristics in road-pavement engineering of PU-asphalt can be identified. The potential of PU-asphalt as a heavy-duty permeable pavement could be demonstrated at laboratory scale. The mechanical performances of PU-asphalt are significantly increased compared to conventional reference materials. Thus, the functional characteristics of porous pavement materials can be connected with a good performance and durability. Without showing increased susceptibility to cracking at low temperatures, PU-asphalt also shows sufficient resistance of deformation at high temperature. Thereby, the service temperature range can be increased towards conventional asphalt. A connection of multifunctionality, superior hydraulic performance with a stable structure and environmental advantages reflects a tremendous innovation potential. The successful development of a high-tech pavement system can contribute to an efficient and permanent transportation infrastructure. Particularly regarding the limited durability of conventional Porous Asphalt (PA), permeable PU-asphalt represents a competitive alternative.
- Chair and Institute of Highway Engineering