Rheological Properties Of Bitumen Research Articles

Development of sustainable Lignin-Based coatings for layered double Hydroxides: Enhancing synergistic Anti-Aging properties in bitumen

Layered Double Hydroxides (LDHs) have poor dispersibility in bitumen and limited effectiveness in enhancing its thermal oxidative aging resistance. To address these issues, this study aims to purify lignin to improve its radical scavenging efficiency and use the purified lignin to coat LDHs (Φ@LDHs), thereby increasing their lipophilicity and radical scavenging efficiency for use in bitumen. sodium lignosulfonate (SL) was fractionated into five parts using a stepwise water/ethanol fractionation method, and these fractions were then applied to coat the LDHs to produce Φ@LDHs. The morphology, antioxidant activity, and chemical structure of Φ@LDHs were analyzed. Subsequently, the effect of Φ@LDHs on the aging properties of bitumen was evaluated. The test results indicated that SL and its fractions effectively coated the surfaces of LDHs, thereby enhancing their interlayer spacing and hydrophobicity. Among all fractions, lower molecular weight fractions, F4 and F5, retained most of the phenolic hydroxyl groups in SL, demonstrating significant antioxidant activities. The incorporation of F4@LDHs and F5@LDHs effectively mitigated changes in rheological properties of bitumen and oxidation product formation during thermal oxidation and UV aging, with F5@LDHs showing the best performance. Furthermore, a synergistic anti-aging mechanism was elucidated for the F4@LDHs and F5@LDHs composites. The purified F4 and F5 fractions not only improved the compatibility of LDHs with bitumen but also delayed the oxidative reactions initiated by free radicals to achieve a synergistic anti-aging effect.

Effect of Nanostructured Shungite on the Rheological Properties of Bitumen

Improving the physico-mechanical characteristics of bitumen is a constant and pressing problem in road construction. The issue is solved by modifying bitumen with various additives, one of which is a nanostructured modifier. This paper examines the effect of adding a natural mineral, shungite, to bitumen from the Koksu deposit (Kazakhstan) after grinding under different conditions. The mechanochemical activation of shungite made it possible to obtain samples with an average particle diameter of up to 3 μm. Using scanning electron microscopy, nanostructured particles with sizes of up to 100 nm were discovered in their structure. The effect of nanostructured shungite on the rheological characteristics of bitumen—elasticity and loss moduli, and loss tangent at high and low temperatures—was studied. The transition temperatures of bitumen from the viscoelastic to the liquid state were established, and their shift to the region of elevated temperatures when modified with ground shungite are shown. The presence of organic and inorganic components in the composition of shungite—carbon, silica, and metal oxides—has a beneficial effect on the rheological properties of bitumen by forming bonds with resinous asphaltene components of bitumen. The use of bitumen modified with nanostructured shungite makes it possible to replace the polymer modifier with a natural mineral to improve the quality of the road surface.

Investigation on Anti-Fuel Erosion Performance of Sasobit/SBS-Modified Asphalt and Its Mixtures.

The fuel leakage of fuel vehicles will exacerbate the occurrence of distresses on asphalt pavements, including peeling, chipping and potholes, especially under the synergistic effect of traffic load and environment. In this research, Sasobit, which is commonly used as a warm agent in asphalt, is selected as the anti-fuel erosion agent and incorporated into SBS-modified asphalt and its mixtures. Diesel and gasoline are selected as the fuel erosion media. Sasobit/SBS-modified asphalt binder and its mixtures are investigated for fuel erosion. The rheological properties of bitumen and the mechanical properties of asphalt mixtures are assessed. The experimental findings show that the dissolution velocity of SBS-modified asphalt with 3% Sasobit is 0.2%/min for diesel erosion, while it is 1.7%/min for gasoline erosion, lower than the control sample without Sasobit. Meanwhile, the rutting factor of Sasobit/SBS-modified asphalt decreases less than that of the control sample without Sasobit. Furthermore, the mass loss ratio after the Cantabro test of Sasobit/SBS-modified asphalt mixtures is 1.2% for diesel erosion, while it is 6.8% for gasoline erosion, lower than that of the control sample without Sasobit. The results of the mechanical properties for asphalt mixtures demonstrate that Sasobit can enhance the anti-fuel erosion performance. Moreover, the research results of the Sasobit modification mechanism show that Sasobit can form a microcrystalline structure in SBS-modified asphalt, which subsequently improves the anti-fuel of asphalt and its mixtures. This research provides a reference for anti-fuel erosion assessment methods and solutions to improve the anti-fuel erosion of asphalt pavement.

THE USE OF GRAPHENE IN THE MODIFICATION OF BITUMEN: A LITERATURE REVIEW

In recent years, nanomaterials in bitumen modification have become widespread due to their superior properties. Graphene and its derivatives are prominent examples of this. Therefore, this review study was conducted to evaluate the effect of graphene on bitumen in detail. Accordingly, by examining the literature studies, general information about graphene and its derivatives was given, and the preparation conditions of graphene-modified bitumen were evaluated. Then, the effect of graphene on the physical and rheological properties of bitumen was investigated. In addition, the impact of graphene modification on the performance of asphalt mixtures and the use of graphene in composite modification was investigated. As a result, it was determined that graphene improves the high-temperature performance of bitumen, but its effect on the low-temperature and fatigue performance of bitumen is mostly negligible. In addition, it has been determined that graphene increases the rutting resistance of bituminous mixtures and positively affects the cracking resistance of bituminous mixtures in general.

Comparison of long-term influence of various recycling agents on bitumen rheological properties

Comparison of long-term influence of various recycling agents on bitumen rheological properties

Effects of rejuvenators and aging conditions on the properties of blended bitumen and the cracking behavior of hot asphalt mixtures with a high RAP content

The utilization of Reclaimed Asphalt Pavement (RAP) in asphalt pavement has obtained global popularity because of its cost-efficiency, technical advantages, and positive environmental influence. However, incorporating RAP requires careful consideration of cracking resistance because of the existence of age hardening of bitumen in RAP. For the mixtures containing high RAP contents, rejuvenators are often applied to enhance the performances of aged bitumen and the cracking of mixtures. This research aims to evaluate the effects of different rejuvenators on the rheological properties of bitumen and the cracking resistance of the mixture under short and long-term aging conditions. To achieve this goal, three rejuvenators - namely, RA1 (petroleum-based), RA2 (waste vegetable oil-based), and RA3 (modified soybean oil-based) were evaluated at contents of 0%, 4%, 12%, and 20%, respectively. The dynamic shear rheometer (DSR) test results show that, under unaged and rolling thin-film oven (RTFO) aging conditions, blended bitumen with RA1 and RA3 have higher G*/sinδ than RA2. Conversely, under pressure aging vessel (PAV) aging conditions, blended bitumen with RA1 and RA3 has lower G*sinδ than that with RA2. Regarding the cracking resistance, the indirect tension asphalt cracking test results show that, under short-term oven aging (STOA) conditions, the mixture using RA2 and RA3 has a higher cracking tolerance index (CTIndex) than the one with RA1. However, under long-term oven aging (LTOA) conditions, the mixture using RA1 has the highest CTIndex value. In addition, the high correlations between G*sinδ with CTIndex and post-peak slope (|m75|) and between the CTIndex and |m75| are observed.

Preparation and Performance of Bitumen Modified by Melt-Blown Fabric of Waste Mask Based on Grey Relational and Radar Chart Analysis.

To effectively utilize waste mask materials in road engineering and minimize resource waste, the melt-blown fabric (MBF) of waste masks was utilized to modify the virgin bitumen. The preparation process of MBF-modified bitumen was investigated, and the physical and rheological properties of bitumen were measured. Subsequently, the blending mechanism during preparation and the dispersion morphology of the modifier were explored. Finally, the pavement performance of the mixture was investigated, and a radar chart analysis was performed to quantitatively assess the effects of MBF modification. Results suggested that the recommended preparation process of shear time, shear rate, and shear temperature was 170 °C, 4000 r/min, and 15 min, respectively. MBF enhanced the high-temperature stability of the binder and weakened the temperature susceptibility. The modification was primarily a physical process. No network structure and agglomeration formed in the bitumen after modification. The addition of MBF significantly improved the resistance of the asphalt mixture to a high-temperature deformation and water damage but harmed its low-temperature crack resistance. The comprehensive assessment results of 0% (f1), 1% (f2), 3% (f3), and 5% (f4) MBF to improve the properties of the mixture were in the following order: f3>f4>f2>f1, where the impact of 3% MBF was the most significant, followed by 5% and 1% MBF.

Rheological and mechanical consequences of reducing the curing time of cold asphalt mixtures by means of magnetic induction

Cold asphalt mixtures are more sustainable because they are manufactured at ambient temperature. However, they are much less applied because they take longer time in the curing process due to the water contained in the asphalt emulsion, which delays the opening of roads. To solve this problem, the option of adding magnetic aggregates to cold asphalt mixtures and heating them by magnetic induction to evaporate the water contained in the asphalt emulsion and reduce curing time has been evaluated. For this objective, different by-products were evaluated as magnetic aggregate and the best one was selected. Four porous asphalt mixtures were then manufactured: an experimental mixture with the selected magnetic particles, a control mixture with virgin steel instead of the by-products, and two oven-cured reference mixtures without magnetic aggregate (one according to the Spanish standard and another according to the U.S. Asphalt Institute guidelines); then, the four mixtures were studied in terms of the curing process, rheological properties of bitumen and mechanical performance of samples. The experimental mixture containing industrial by-products shortened the curing time from 7 and 2 days (Spanish and U.S. Asphalt Institute standard, respectively) to only two hours; rheological and mechanical analysis proved the viability of this technology.

Effects of using waste solid sheet photopolymer plates in combination with SBS on the rheological properties of bitumen

ABSTRACT Large quantities of Solid Sheet Photopolymer plates (SSP) are used and wasted by the flexographic printing industry worldwide. The use of waste SSP, contains valuable polymers for bitumen modification, is an effective way of disposing of post-consumer products and an alternative way of obtaining new modifiers with good properties. Styrene–butadiene-styrene (SBS) copolymer, which is widely used in bitumen modification, causes excessive costs. The purpose of this study is to look at the effects of using SSP in combination with SBS and how much SSP saves on SBS content. Dynamic Shear Rheometer (DSR), Multi-Stress Creep Recovery (MSCR), Bending Beam Rheometer (BBR), Storage Stability tests, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) were carried out. The performance of the 4 and 5 wt.% single SBS modifications was compared with the SBS + SSP combination. SBS and SSP additives were found to interact well, and the use of 7% SSP in combination with 2% SBS provided improved low and high temperature performance and storage stability compared to the single 5% SBS modification. The use of waste SSP, which is cheaper than bitumen, together with SBS in bitumen modification offers a cost-effective and environmentally friendly solution without compromising performance.

Recycling shredded waste cigarette butts as stabilising fibres in stone mastic asphalt concretes

ABSTRACT Considering the global burden of cigarette consumption, the disposal of cigarette butts has become an inevitable issue. Compared to traditional disposal methods, such as landfilling or incinerating, the recycling of these wastes is clearly an eco-friendlier solution. In this research, waste electronic cigarette butts (E-CBs) were collected and recycled in bituminous mixtures, aiming to increase the use of sustainable road construction materials. The objective of this research is to explore the possibility of using waste E-CBs as an alternative stabilising fibre in asphalt mixtures. To this end, shredded waste E-CBs were incorporated in Stone Mastic Asphalt (SMA) and compared with the conventional cellulose fibres. Furthermore, to investigate the effects of powders (below 0.063 mm) from the waste E-CBs on the rheological properties of bitumen, tests were conducted on base SBS-modified bitumen and its mastics. Results show that the waste powder was unfavourable to the thermal susceptibility of the resulting binder. SMA samples with shredded E-CBs were also characterised through physical and mechanical tests and compared to the reference mixture using cellulose fibres. It was concluded that using waste E-CBs in SMA can be considered a promising alternative for replacing cellulose fibres and avoiding the disposal of cigarette butts.

Adsorbing Volatile Organic Compounds within Bitumen Improves Colloidal Stability and Air Quality

The mass loss of bitumen due to volatilization is one of the deterioration mechanisms through which the chemical composition of bitumen deviates from its original condition, leading to change in the physical and rheological properties of bitumen. The emissions from bitumen not only accelerate its aging but also negatively impact air quality and consequently human health. Here, we characterized the molecular compositions of the volatiles emitted from bitumen in an isothermal aging process (150 °C for 24 h). We also investigated the impact of losing these compounds on the association behavior of asphaltene stacks. Based on the GC-MS results, the main mass loss of SARA (saturates, aromatics, resins, asphaltenes) fractions is attributed to the emission of lightweight nonpolar aromatic and aliphatic compounds. The most dominant volatiles are single-ring aromatics carrying short side chains, followed by saturated and unsaturated aliphatic compounds including short-chain n-alkanes, iso-alkanes, cyclic alkenes, alkenes, and dienes. Using molecular modeling in the framework of density functional theory (DFT), we showed how the reduction in aromatics and saturates can impact the colloidal stability of asphaltenes in the matrix of bitumen. Based on the DFT results, the surface adsorption of aromatics and saturates on asphaltene planes provides the steric repulsion required to maintain the asphaltene planes at a distance sufficient to inhibit their agglomeration. In addition, aromatic molecules with the least hindrance repulsion can disturb the π–π interfacial interactions between asphaltene planes, facilitating their deagglomeration. Therefore, a direct consequence of the mass loss of bitumen due to volatilization is disturbing the asphaltene distribution within the bitumen and stimulating the aggregation of asphaltenes. We also studied the merits of incorporating biochar into the bitumen surface to reduce bitumen’s mass loss. Modification of bitumen separately with each of six biochars derived from biomass feedstocks (walnut shell, peanut shell, Douglas fir, pine bark, birch, and algae) showed the efficacy of each biochar to reduce the volatiles emitted from bitumen, thereby reducing the changes in the composition of maltene with consequent colloidal stability losses. The study outcomes highlight the importance of reducing emissions from bitumen to delay its aging and minimize negative impacts on air quality and human health.

Effects of Liquefied Waste Plastics on Chemical and Rheological Properties of Bitumen

Effects of Liquefied Waste Plastics on Chemical and Rheological Properties of Bitumen

Effect of Various Dynamic Shear Rheometer Testing Methods on the Measured Rheological Properties of Bitumen

A 23 factorial design experiment was conducted to study the influence of pre-heating temperature (HT) for manufacturing sample, bonding temperature (BT) onto rheometer, and trimming state (Trim) of the sample on complex shear modulus (G*) and phase angle (δ) using a dynamic shear rheometer on unmodified bitumen of types 50/70, 70/100, and two 160/220 from various sources. In addition, the black diagram and 2S2P1D model were used to evaluate the viscoelastic properties of bitumens. Findings show that the G* is more sensitive to the changes than the δ. Additionally, it was found that the 8 mm parallel plate diameter had a higher sensitivity to the trimming state than the 25 mm. The tested factor HT generally did not have a statistically significant impact on the results of the tested materials, except for 160/220_I. At practically all the temperatures tested for 50/70 and 160/220_II, the G* dropped by increasing the factor BT from a lower to a higher value. The Trim:BT interaction has the greatest impact on all materials and temperatures on G*, except for 160/220 at lower temperatures. However, in the case of δ, the Trim:BT interaction has the most significant effects for 70/100 and 160/220_II. The black diagrams show no discernible differences, which may be a result of the limited range of changes made to the variables.

Nanosilica Types and Their Influences on the Rheological Properties of Bitumen

Nanosilica (NS) has been involved in many investigations over bituminous materials. Although nanosilica is variable in size and type, most literature has failed to consider or acknowledge its type and/or size impacts. Hence, this research focused on this knowledge gap by considering 20-nm, 20-nm with couplant, and 60-nm NS types for some index, rheological shear, and creep tests. Tests were conducted at virgin, short-term, and long-terms aging conditions as well. Estimations of rutting and fatigue resistances were found to be promising at different extents. Generally, 60-nm NS was better for rutting, whereas 20-nm NS was more efficient for fatigue. Initially, dry blending was considered during sample preparations. However, wet blending was also used later for extra samples and limited shear oscillation tests. Some discrepancies in dry-prepared results were found to be attributed to mixing conditions. Outcomes of experiments after wet blending showed more consistent and reliable direct relationships between sample properties and NS contents. Hence, coarse NS at higher ranges, typically at 8% usage, was more efficient than other batches.

SUPERPAVE: ЗА І ПРОТИ, АБО ЧИМ НАМ КОРИСНИЙ SUPERPAVE

The main positions of the Superpave system regarding the principles and methods of predicting the durability of asphalt concrete in various environmental and transport conditions of their operating are considered. Arguments in favor or unacceptability of bitumen and asphalt concrete quality indicators provided by the system are presented. This concern: methods of design of compositions according to Fuller, assignment of asphalt concretes according to volumetric and spatial characteristics, obtaining of physical and rheological properties of bitumen. Attention is focused on the methods and criteria of laboratory compaction of asphalt concrete samples; attention is paid to the properties of asphalt concrete that give the most objective idea about the work of asphalt concrete in road layers (rutting resistance and fatigue). It is emphasized that the system does not consider water resistance and crack resistance of asphalt concrete. Attention is drawn to difficulties of an instrumental, financial and organizational nature regarding the implementation of the system in Ukraine. Keywords: bitumen, asphalt concrete, PG-zone, rutting resistance, stiffness, module, composition, compaction, zoning.

Influence of material factors on the determination of dynamic moduli and associated prediction models for different types of asphalt mixtures

In a Mechanistic-Empirical (ME) pavement design system, the dynamic modulus is used to characterise asphalt mixtures, which are affected by many factors including environmental conditions and material properties. This study examined twenty types of asphalt mixtures containing nine types of bituminous binders that are commonly used for construction of road pavements in Norway. The objective of the study was to investigate the relationship between material factors and dynamic modulus. The dynamic moduli of asphalt mixtures were experimentally determined employing cyclic indirect tensile tests and were modelled with master curves implementing the sigmoidal function. The rheological properties of bitumen were characterised using a dynamic shear rheometer. The viscosity was simulated using a temperature-based log-linear relationship and the complex modulus was obtained based on the modified Huet-Sayegh model. The grey relational analysis revealed the correlation existing between the material factors and the dynamic modulus. A prediction model was established using a Multiple Linear Regression (MLR). The results indicate that the dynamic modulus of asphalt mixtures is greatly affected by the following parameters ranked in order of decreasing significance: viscosity and complex modulus of the binder, void filled with bitumen, air void content, bitumen penetration and softening point. Based on the MLR model, the correlation between the dynamic modulus and the bitumen viscosity and complex modulus fit well with Coefficient of Determination (R2) ≥ 0.901. The determination of the sigmoidal function parameters to predict the dynamic modulus had good reliability with R2 ≥ 0.973. This study contributes to the development of an accurate and convenient method to predict the dynamic moduli of asphalt mixtures based on the material factors for a ME pavement design system.

Phase transition process of sulfur in bitumen and its effect on rheological properties of bitumen

Partial substitution of sulfur for bitumen helps reduce bitumen consumption while promoting recycling of the sulfur in waste residues. The properties of sulfur-extended bitumen (SEB) are closely related to the chemical reaction process and the phase transition process of sulfur in bitumen, and these two processes are influenced by sulfur dosage and curing time. Therefore, SEB samples with sulfur dosages of 1 %, 5 %, 10 %, 15 %, 20 %, 25 % and 30 % were prepared and cured for 0, 15, 30, or 60 days. Differential scanning calorimetry was conducted to understand the sulfur recrystallization process in bitumen, and a dynamic shear rheometer was used to analyze the rheological properties of SEB samples. Results show that molten sulfur can turn to monoclinic sulfur immediately after cooling; the monoclinic sulfur gradually turns to orthorhombic sulfur, and the ratio between the two forms stabilizes after curing for 15 days. The recrystallization of sulfur in bitumen needs sufficient curing time, and the sulfur states in bitumen vary depending on the sulfur dosage. When the sulfur dosage is lower than 15 %, sulfur dissolves into bitumen. The dissolved sulfur softens the bitumen and increases its low-temperature properties and resistance to fatigue cracking. When the sulfur dosage is 10 %, 15 %, 20 %, 25 %, or 30 %, surplus sulfur is recrystallized to orthorhombic sulfur. When the sulfur dosage is 35 % or more (the dosages evaluated in the former study), surplus sulfur is recrystallized to monoclinic sulfur. The chemically crosslinked sulfur and recrystallization sulfur help increase the elastic component in bitumen and improve the rutting resistance and fatigue life of bitumen. However, when the sulfur dosage exceeds 20 %, the effect of stress concentration stands out due to bulk gathering of recrystallized sulfur, and this effect stops further improvement in the fatigue life of SEB samples. The effects of recrystallization sulfur on bitumen are mainly concentrated in the first 15 days of curing time, even though much more recrystallized sulfur is detected after more curing time, even at 60 days (the longest curing time evaluated in this study). Therefore, a curing time of 15 days is sufficient for accurate evaluation of SEB properties.

Effects of Pruning Residues from Blueberry Bushes Powder on the Physical and Rheological Properties of Bitumen

Bitumen is a hydrocarbon product prone to oxidative aging. For this reason, the aim of this study is to evaluate physical and rheological properties of modified bitumen with pruning residues from blueberry bushes powder (RPA), anti-aging natural compound, to reduce the oxidative damage of bitumen. Rolling thin film oven test (RTFOT) was performed to simulate short term aging of modified bitumen with 2, 6 and 10% RPA by weight. The results of conventional tests (penetration, softening point, ductility and rotational viscosity) indicated that the addition of RPA increases the stiffness of bitumen and decreases its temperature susceptibility. In addition, dynamic shear rheometer test (DSR) shows that modified binders improve their resistance against deformation and enhance their elastic response. The 6% RPA binder demonstrated better oxidative aging resistance without compromising its performance at low temperature.

Effect of asphaltene on the rheological properties of bitumen

In this paper, the rheological behavior of bitumen as a function of asphaltene concentration has been studied. Several bitumen samples having distinctly different amounts of asphaltene were prepared and characterized using differential scanning calorimetry and rheological measurements. The glass transition temperature of bitumen increases with an increase of the asphaltene concentration. This correlation can be used to estimate the asphaltene concentration of bitumen samples using DSC measurements. Small-amplitude oscillatory shear data for the bitumen-derived samples were fit by the generalized Maxwell model with good agreement. A constitutive model is proposed, where the zero-shear complex viscosity of the bitumen sample is a strong function of the asphaltene concentration, and it can be used to predict the asphaltene concentration.

Performance evaluation of bitumen modified with styrene–isoprene-styrene and crumb rubber compound

Modifying bitumen with polymers has become inevitable to achieve resistance to severe traffic and environmental conditions. Researchers have focused on using modifiers with low-cost additives, such as crumb rubber (CR) obtained from waste vehicle tires, to enhance the efficiency of polymer modification. The present study investigated the effects of using styrene–isoprene-styrene (SIS) alone and in combination with CR on conventional and rheological properties of bitumen. To this end, viscosity, softening point, penetration, bending beam rheometer (BBR), and dynamic shear rheometer (DSR) tests were conducted. Elastic properties and performance grading were evaluated by the multi-stress creep recovery (MSCR) test. The use of 3% SIS with 7% CR gave one degree higher high-temperature performance level and 15% lower low-temperature stiffness than 6% SIS modification. It also provided 2.5 times lower non recoverable creep compliance and 1.5 times higher percent recovery than 6% SIS modification at 64 °C. The combined use of SIS and CR provided satisfactory performance under low- and high-temperature conditions and ensured a cost-effective solution when compared to the use of SIS polymer alone. Although SIS and CR modified binders exhibited satisfactory rutting resistance and elastic properties, the percent-difference criterion significantly restricted their high-temperature performance grade. According to this criterion, modification makes the binders suitable for extremely heavy traffic conditions without changing the resistance against temperature. Furthermore, it was determined that the estimated softening point, viscosity and rutting parameter values as a function of SIS and CR contents are highly compatible with the experimental results.