Effects of Warm Asphalt Additives on Asphalt Binder and Mixture Properties (original) (raw)
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Rheological Evaluation of Short- and Long-Term Performance for Warm Mix Asphalt (WMA) Binders
8th RILEM International Symposium on Testing and Characterization of Sustainable and Innovative Bituminous Materials
Warm-mix asphalt (WMA) additives are environmentally friendly and cost-effective products that lower the viscosity of bituminous binders to allow reduction of mixing and compaction temperatures in asphalt mix production. In this study, two WMA additives were used; Sasobit® and Advera®. Both were mixed in the lab with unmodified 60/70 Pen and modified PG 76-22 binders. Strain oscil- lation and viscosity measurement tests were performed to determine the rheological properties of the binder with and without WMA additives. Different ageing pro- cesses were performed in this study; half and full short-term ageing using the Rolling Thin Film Oven (RTFO) procedure, and long-term ageing using the Pressurized Ageing Vessel (PAV) procedure. Test results have shown that the addition of Sasobit® increased the stiffness of both binders and changed PG grade by one unit up (6 °C PG grade). Also, Sasobit® presented better rutting resistance in modified and unmodified binders than Advera®, while both WMA additives decreased the fatigue cracking resistance. Multiple Stress Creep Recovery (MSCR) test was also conducted on both unaged and RTFO aged binders. Modified binder with Sasobit® and Advera® exhibited the same performance of the original binder after complete short-term ageing. However, Sasobit® increased the potential of rutting resistance in the unmodified binder more than Advera® did. The viscosity measurements revealed that adding Sasobit® to modified or unmodified binders lowered the viscosity more than Advera® did. These measures were considered as preliminary data required for further studies on the effect of WMA additives on the resistance of bituminous binders to fatigue cracking.
Laboratory Simulation of Warm Mix Asphalt (WMA) Binder Aging Characteristics
Airfield and Highway Pavements, 2008
As warm asphalt has been gaining increasing popularity in the recent years, there are still several characteristics about warm asphalt that are unknown. While several studies have been conducted to study the performance of warm asphalt mixtures, aging characteristics of warm asphalt binders are not known in great detail as the technology is relatively new, and there are no old pavements to study the aging behavior of warm asphalt. This paper presents the results of a study conducted to simulate the aging of warm asphalt binder in the laboratory by preparing asphalt mixtures containing two different binder sources and three different warm asphalt additives (Control, Asphamin® and Sasobit®). The mixtures were artificially aged in the oven, and the binders were extracted for testing. The binders extracted from freshly prepared samples were considered being short term aged binders and binders extracted from oven aged mixtures were considered being long term aged binders. Results of several tests (e.g., viscosity, high and low temperature properties, Gel Permeation Chromatography, etc.) are presented in this study. The results indicated that the binders extracted from the warm mix asphalt (WMA) had significantly lower aging index (ratio of the viscosity of extracted binders to original binders) compared to the binders extracted from control hot mix asphalt (HMA). It was also observed that the binders extracted from the WMA had aged significantly lower compared to binders extracted from control HMA. The results indicated that the warm asphalt additives did not have any significant effect on the fatigue cracking parameter (G*.sin δ) or the creep stiffness of the binders. However, Asphamin® significantly increased the m-value of the binders.
Thermo-rheological analysis of WMA-additive modified binders
Materials and Structures
Thermo-rheological characteristics of unmodified and modified bitumen have significant impacts on the mechanical response of asphalt. This study investigates the impacts of an organic and a chemical Warm Mix Asphalt additive on bitumen thermo-rheological and mechanical characteristics. Modified binders with different concentrations of each additive were studied and analysed comparatively to a 40/60 penetration grade bitumen. Frequency sweep tests were performed at different ageing levels to characterise the Linear Viscoelastic properties. The multiple stress creep and recovery, linear amplitude sweep (LAS) and low temperature creep stiffness tests, together with the Glover–Rowe (G–R) fatigue parameter (determined from fitting of the 2S2P1D model to the complex shear modulus and phase angle master curves) were used to analyse the performance of the binders at critical operating temperatures. The results demonstrated the necessity to analyse the behavior of the studied binders beyond ...
Evaluation of the rheological behaviour of Warm Mix Asphalt (WMA) modified binders
Advanced Testing and Characterization of Bituminous Materials, 2009
Several processes and products are available to produce warm mix asphalt (WMA). The use of those may reduce the mixing and compaction temperatures in relation to hot mix asphalt (HMA), ensuring a good performance of the pavement. Lower plant mixing temperatures mean reduction in fuel consumption and lower emissions, what may contribute to diminish odours and health problems. A laboratory study on the properties of the modified binders (using two commercial WMA additives-Sasobit ® and Cecabase ®) was carried out through conventional (penetration, softening point), dynamic viscosity and rheology (DSR) tests, in order to establish the optimum additive content. Stripping of binder from the aggregates is a reported problem in WMA. Thus, the affinity of the modified binders was assessed without encountering significant problems. It was also observed that only Sasobit ® alters the viscosity of the binder. A maximum temperature reduction of 15°C was achieved using 4% of Sasobit ® with a softer binder.
Effects of non-foaming WMA additives on asphalt binders at high performance temperatures
Fuel, 2012
Due to many reasons including the energy reductions and environmental benefits, warm asphalt has been gaining increasing popularity in recent years around the world. In the present study, the objective was to conduct a laboratory investigation of rheological properties of non-foaming WMA additives at high performance temperatures. The conventional testing procedures such as viscosity, performance grade, creep and creep recovery, amplitude sweep and frequency sweep as well as specific Fourier Transform Infrared Spectroscopy (FTIR) were performed to determine the influences of non-foaming additives on asphalt binders. The experimental design included eight binders and four non-foaming WMA additives. The test results indicated that, the non-foaming WMA additive can slightly reduce the viscosity value of asphalt binder and thus decrease the mixing and compaction temperatures of the mixture. The binders containing non-foam additive have a slight increase in high failure temperatures compared to control binder and thus improving the rutting resistance of the mixtures. In addition, creep recovery, amplitude and frequency sweep tests show that the binders with Sasobit has a slightly higher complex modulus but exhibits lower creep compliance and phase angle than the binder containing other WMA additives regardless of asphalt type and grade. Furthermore, FTIR analysis results indicate that the binder type plays a key role in determining the rheological properties of WMA binders.
Influence of Short-Term Aging on Rheological Characteristics of Non-Foaming WMA Binders
Journal of Performance of Constructed Facilities, 2012
The objective of this study was to conduct a laboratory investigation of rheological properties of non-foaming warm mix asphalt (WMA) binder after a short-term aging procedure. The conventional testing procedures such as viscosity, performance grade, creep and creep recovery, amplitude sweep, and frequency sweep were performed to determine the influences of non-foaming additives on asphalt binders. The experimental design included four binders and four non-foaming WMA additives. The test results indicated that, as expected, the nonfoaming WMA additive can reduce the viscosity value of asphalt binder and thus decrease the mixing and compaction temperatures of the mixture. The failure temperatures of unaged and rolling thin film oven (RTFO) binders containing non-foam additives have a slight increase compared with the virgin binder, therefore improving the rut resistance of the mixtures. In addition, the creep recovery, amplitude, and frequency sweep tests show that the unaged and RTFO binders with Sasobit have a slightly higher complex modulus but exhibits lower creep compliance and phase angle than the binder containing other WMA additives.
A STUDY ON THE VARIATION OF VISCOSITY AND FILM THICKNESS OF MODIFIED BINDERS AT VARIOUS TEMPERATURES
The government of India has setup an investment plan of Rs.3,23,000 crores in the 12 th five-year plan for road construction and infrastructure industry. In addition, more than twice this amount is likely to be contributed by the private investors engaged in road sector industry. Taking into account this considerable investment in road construction, it is required that robust design methods are followed during the initial phase of construction, as maintenance cost of these structures are likely to be higher than the initial expenditure for construction. Hence considerable research and development work in terms of material characterization is urgently required.
Canadian Journal of Civil Engineering, 2013
Warm asphalt has been gaining increasing popularity in recent years around the world due to many reasons including the energy reductions and environmental benefits. In the present study, the objective was to conduct a laboratory investigation of rheological properties of eight binders with four non-foaming warm mix asphalt (WMA) additives at intermediate and low performance temperatures in terms of Superpave low temperature test criteria. The conventional testing procedures such as dynamic shear rheometer (DSR), bending beam rheometer (BBR) test as well as specific Fourier transform infrared spectroscopy (FTIR) were performed to determine the influences of non-foaming additives on asphalt binders after a long-term aging procedure. The test results indicated that the binder type and source play key roles in determining the G*sin ␦ values of WMA binders with the non-foaming WMA additive. All eight binders containing Sasobit generally have higher creep stiffness values compared to the binders with other WMA additives. The FTIR tests illustrated that the absorbance of the C-O stretch and C-H bend regions of the WMA binders after a short and long-term aging procedure can be considered similar. Moreover, the WMA binders generally exhibit better performance properties than control binders at intermediate and low temperatures after a long-term aging procedure. Furthermore, FTIR analysis results indicate that the binder type and source play important roles in determining the rheological properties of WMA binders.
Journal of Fundamental and Applied Sciences, 2017
The performance of asphalt pavement is mainly governed by the properties of the binder. Many asphalt pavement distress are pronounced to be related to the rheological properties of asphalt binder. The oxidation changes the structure and composition of asphalt binder resulting stiffer and brittle of asphalt. This paper described SuperpaveTM binder that was used to characterize the rheological properties of PG64 asphalt binders blended with various Advera® contents subjected to unaged and short term aged. Rotational viscometer (RV) and Dynamic Shear Rheometer (DSR) were conducted to measure binder properties at higher and intermediate temperature respectively. The results indicated that, the addition of Advera® in the asphalt binder exhibited change in binder rheology which influenced rutting parametery
Additives Influence on the Properties of Asphalt Binders: A Case Study
Engineering, Technology & Applied Science Research
This study investigated the impact of using modified bitumen binders and additives to enhance the physical characteristics of asphalt mixtures at high, medium, and low temperatures. Both basic and rheological characteristics of the bituminous binders were tested by adding Styrene-Butadiene-Styrene, a type of thermoplastic elastomer, as a chemical additive to asphalt mixtures at various fractions (3.5%, 4%, and 4.5%), and two kinds of modified Bitumen: Kraton styrene block copolymers and Europrene (SOL T 6302). The following methods were used to test the properties of the binders: needle penetration, ductility, softening point, resistance to hardening when exposed to heat and air, Pressure Aging Vessel test dynamic (PAV), Shear Rheometer (DSR), Bending Beam Rheometer (BBR), direct tension test, and storage stability. The results showed that the best properties of the asphalt concentration were observed when using 4% of additives, while the penetration of Bitumen was reduced to 27.2% ...