Jan Król

Quality assessment of bituminous binders based on the viscoelastic properties: Polish experience

Construction of modern and durable bituminous pavements requires high quality bituminous binder, aggregates and additives. The main objective of this paper was to analyse and compare viscoelastic properties of unmodified and polymer modified bitumens produced in Poland, Europe, in order to assess their quality. In this paper there are presented results of bituminous binder European classification tests (penetration, softening point and Fraass breaking point) as well as rheological test results conducted over a wide range of temperatures. In addition, image analysis of the microstructure of selected polymer modified bitumens is also presented. Based on the analysis it was concluded that although bituminous binders complies with European specification requirements, they are significantly different in terms of their rheological properties. It was found that regardless of binder producer, bituminous binder within the same hardness group exhibit different low and high temperature properties.

Rubber modified bitumen

Abstract: Among several methods of waste rubber recycling, the reuse of crumb rubber for bitumen modification deserves special attention. The chapter includes a review of methods for bitumen modification with crumb rubber, a discussion of the types of bitumen–rubber interactions, and a description of the properties of rubber–modified bitumen and asphalt–rubber mixtures. It also summarizes the benefits from the use of asphalt rubber mixtures in road construction.

The study of the effect of internal structure on permeability of porous asphalt

X-ray computed tomography (CT) and laboratory permeability techniques were applied to study the internal properties of porous asphalt mixture. Specimens containing aggregate of different gradations and of different mineral compositions were prepared in the laboratory. The air voids of all the specimens were determined in the laboratory and the specimens were then scanned in X-ray CT. The same samples were then tested for laboratory permeability. The active air voids and contact points of aggregate with nearby aggregate particles were determined from X-ray CT images. The laboratory permeability test results were found in comparison with X-ray CT values of voids’ internal connectivity. A comparatively high permeability value was observed for porous asphalt with maximum aggregate size irrespective of its mineral composition. The size of air voids and volume of active (connected) air voids were also found high for mixtures made up of large aggregate size. The difference in mineral composition of aggregate was found to have considerably less effect on permeability of porous asphalt.

Towards Understanding the Polymerization Process in Bitumen Bio-Fluxes

Bitumen is a commonly used material for road construction. According to environmental regulations, vegetable-based materials are applied for binder modification. Fluxed road bitumen containing a bio-flux oxidation product increases the consistency over time. The efficiency of crosslinking depends on the number of double bonds and their position in the aliphatic chain of fatty acid. The main goal of this paper was to examine the structural changes taking place during hardening bitumen with bio-flux additives. Two types of road bitumens fluxed with two different oxidized methyl esters of rapeseed oil were used in this study. Various chemical and rheological tests were applied for the fluxed-bitumen at different stages of oxygen exposure. The oxidation of rapeseed oil methyl ester reduced the iodine amount by about 10%–30%. Hardening of the fluxed bitumen generally results in an increase of the resins content and a reduction of the aromatics and asphaltenes. In the temperature range of 0 °C to 40 °C, bio-flux results with a much higher increase in the phase angle than in temperatures above 40 °C in the bitumen binder. The increase in the proportion of the viscous component in the low and medium binder temperature is favorable due to the potential improvement of the fatigue resistance of the asphalt mixture with such binders.

Traffic analysis and pavement technology as a tool for urban noise control

Traffic related noise is currently considered as an environmental pollution. Paper presents results of multidirectional study attempting to serve urban traffic without the need to erect noise barriers interfering urban space. Initial concept of the road expansion included construction of 1000 m of noise barriers dividing city space. Improvement in the acoustic conditions after construction completion is possible due to the applied noise protection measures: vehicle speed limit, smooth of traffic flow, use of road pavement of reduced noise emission and the technical improvement of the tramway.

New concept of sustainable road structure with RAP binder course using bio-agent

Growing demand on paving materials requires application of recycling materials. In some countries Reclaimed Asphalt Pavement (RAP) is commonly used for construction of road pavements structural layers. Often limitations are applied in order to amount and type of recycled materials. In this paper a new, innovative concept of asphalt structure for local roads is proposed. In such structure each layer includes bioorigin material or materials from recycling. Research work conducted under the “Use of eco-friendly materials for a new concept of Asphalt Pavements for a Sustainable Environment” (APSE) project consist of complex analysis of opportunities for application into each structural layer material from recycling, including asphaltorigin materials. A proposed new structure will composed of surface layer with bioethanol modified eco-asphalt. For interlayer increased amount of RAP is going to be used due to application of bio-agent rejuvenating binder property. In non-asphalt base layer material from infrastructure demolishing will be used, including demolished cement concrete. In this paper test result of asphalt mixes composed with using of the bio-agent and RAP are presented. It was proofed that higher than typical amount of RAP can be applied for the production of asphalt mixture in traditional asphalt mix plant not equipped with double barrel. Results proofed that bio-agent serves the role of rejuvenator in asphalt mixture and allows for either application of higher RAP content of production of the mixture in lowered technological temperature.

Innovative SMA-MA mixture for bridge asphalt pavement

Paper presents innovative technological solution applied in bridge pavement. New asphalt mixture, called SMA-MA, uses benefits of both mastic asphalt (MA) widely used as a bridge waterproofing layer and stone mastic asphalt (SMA) and provides more durable mixture. According to the wide research plan, several mixtures were tested for their resistance to permanent deformation, water susceptibility, fatigue and aging resistance. Conducted research proved that such mixture can be successfully used as waterproofing and protective layer as well as traffic carrying layer. In comparison to the typically used asphalt mixtures (SMA, MA or asphalt concrete), SMA-MA presents: mixture resistant to permanent deformation with very low air voids content (about of 0.5%) reachable with typical asphalt mixture compaction temperature of 180°C. The temperature of application SMA-MA mixture is about 30°C less than temperature of mastic asphalt, but the ability of sealing is comparable. SMA-MA mixture is a fast application technology using conventional equipment. In climatic conditions of middle Europe showing high number of freezingthawing cycles, it is recommended to use such innovative technological solution on bridge decks.