A novel method to characterise asphalt binder at high temperature

New regulations on bitumen fumes and aerosols, along with increasing traffic and climatic loads on highways, demand innovative construction materials. In this investigation, a novel isocyanate-based bitumen additive was used to pave 0.5 km of an asphalt binder layer with 50% reclaimed asphalt at 20-30°C below hot mix asphalt (HMA) temperatures, in Germany. During construction, bitumen fumes and aerosols were measured for both reference and modified asphalt mixtures. The reference mixture was paved using a similar mixture but with standard polymer modified bitumen, at standard HMA temperatures. For the investigation, a bitumen 70/100 was modified with 2.0% by wt with this novel isocyanate-based additive in an in-line procedure directly at an asphalt mixing plant without affecting production times. Bitumen and asphalt tests were conducted in the laboratory, on asphalt gathered from the construction site. Due to the temperature reduction, the emissions could be considerably reduced, while maintaining comparable asphalt performance..

Section: Dynamic Shear Rheometer Testsmentioning

confidence: 99%

Section: Bitumen Testsmentioning

confidence: 99%

Investigation on the use of a novel chemical bitumen additive with reclaimed asphalt and at lower mix production and construction temperatures: a case study

Gómez

Oeser

2021

“…DSR measurements based on the binder-fast-characterisation-test (BTSV), according to German Standard DIN 52050 (2018), were used for rheological characterisation of the progressively aged asphalt binder. As presented by Alisov et al (2020) and Schrader et al (2020), the test procedure of the BTSV test can be used for a fast and easy rheological characterisation of plain, aged and blended asphalt binders. Two key parameters obtained from BTSV testing are used for characterisation and differentiation of asphalt binders: the temperature T BTSV , where the shear modulus is 15 kPa, and the corresponding phase angle δ BTSV .…”

Section: Rheological Testingmentioning

confidence: 99%

“…Two key parameters obtained from BTSV testing are used for characterisation and differentiation of asphalt binders: the temperature T BTSV , where the shear modulus is 15 kPa, and the corresponding phase angle δ BTSV . In previous publications, these BTSV values were determined for a set of 205 different virgin asphalt binders, which were classified according to their penetration grade (Alisov et al, 2020;Schrader & Wistuba, 2019). Figure 1 presents the test results in form of boxes, which include combinations of T BTSV and δ BTSV for specific penetration grades.…”

Section: Rheological Testingmentioning

confidence: 99%

Rheological, spectroscopic and microscopic assessment of asphalt binder ageing

Koyun

Büchner

Wistuba

et al. 2020

Self Cite

Asphalt binder ageing leads to significant changes in mechanical and physicochemical properties and often to premature cracking in asphalt pavements. A polymer-modified asphalt binder is repeatedly aged through laboratory techniques, i.e. rolling thin film oven test and pressure ageing vessel. The resulting properties of the aged binder are analysed using dynamic shear rheometer, Fourier transform infrared spectroscopy, atomic force microscopy and cryo-environmental scanning electron microscopy. Rheological, spectroscopic and macroscopic properties change progressively with the level of laboratory ageing. Surprisingly, this change shows approximately a linear trend. The first ageing step has the highest impact on the property change, whereas all the following ageing steps result in similar but reduced impact. Moreover, there is a strong interdependency between different mechanical and physicochemical properties. Hence, novel insights into the mechanics of asphalt binder ageing and into the search for ageing laws for asphalt binders.

“…It was concluded that this temperature is a rather good estimation of the softening point for the studied unmodified binders, but not for the PMB. This iso-modulus approach was also adopted by Alisov et al (2020) to develop a new bitumen evaluation system with the BTSV method (Bitumen-Typisierungs-Schnell-Verfahren in German, meaning Binder-Fast-Characterisation-Test in English). The BTSV method is based on the complex shear modulus of bitumen equal to 15 kPa at 10 rad/s.…”

Section: Introductionmentioning

confidence: 99%

Quantitative relationship of fundamental rheological properties of bitumen with the empirical Ring and Ball softening point

Zhu

Lu²,

Langfjell³

et al. 2021

This paper employs the linear viscoelastic parameter G /tanδ as the quantitative criterion for identifying a common relationship with the Ring and Ball softening point of both unmodified and polymer-modified bitumen (PMB). Temperature sweep was conducted at 10 rad/s with dynamic shear rheometer to determine the complex shear modulus G * and phase angle δ of bitumen. The parameter G /tanδ could be obtained. Logarithmic interpolation was applied for G /tanδ to determine the equivalent softening temperature T s_G /tanδ at which G /tanδ equals the proposed criterion values. With this method, a good agreement could be reached between T s_G /tanδ and the softening point for both unmodified bitumen and PMB. While keeping high accuracy for unmodified bitumen, the accuracy of T s_G /tanδ as an estimation of the softening point of PMB was largely improved when compared to the iso-modulus approach. The reliability of this quantitative relationship is preliminarily verified and its implementation is discussed in the Black space.