Mechanical Properties Of Asphalt Binder Research Articles

A Study of the Bond Strength and Mechanism between Basalt Fibers and Asphalt Binders

The bond strength between basalt fibers and asphalt binders is an important parameter that can be used to evaluate the influence of basalt fibers on the mechanical properties of asphalt binders and asphalt mixtures. To date, however, there remains a lack of methods that can be used to assess the bond strength between basalt fibers and asphalt binders. This study employed a fiber-asphalt pull-out tester (POT). Significant upward, peak, and downward stages were observed from the relationship curves between the pull-out force (POF) and displacement, corresponding to the holding stage and reaching the maximum POF stage and the sliding or failure stage between fibers and asphalt binders. Maximum POF is recommended to calculate the bond strength between basalt fibers and asphalt binders. The types of asphalt binders suitable for basalt fibers and the appropriate fiber embedding depths for different types of asphalt binders guiding the selection of fiber length are recommended based on the influence of fiber embedding depth and asphalt binders on the fiber–asphalt bond strength. In addition, surface energy was used to calculate the bond strength as well. Surface energy was determined from contact angle measurements using the sessile drop method. Furthermore, a scanning electron microscope (SEM) was employed to examine the bond mechanism between asphalt binders and basalt fibers. These experiments showed how basalt fibers serve to reinforce asphalt mixtures by bonding with asphalt binders.

Thermoreversible aging in asphalt binders

It is an undisputed fact that aging increases the risk of low-temperature cracking in asphalt pavement. Previous studies on aging have focused on oxidative aging, but few studies on thermoreversible aging have been reported. The existing literature has shown that thermoreversible aging has the same effect as oxidative aging on cracking of asphalt pavement in cold region, so it is obvious that the study of thermoreversible aging is of great practical significance to improve cracking of asphalt pavement. This paper introduces the current status of thermoreversible aging research from the concept, mechanisms, characterisation methods and effects, presents the problems of existing research and indicates the direction of further research, which is important for accurately characterising the mechanical properties of asphalt binders, controlling the waste addition ratio and improving the durability of asphalt pavement.

Revealing the dependance of mechanical properties of asphalt binder on graphene size via multi-scale methods

Elucidating the specific interaction between graphene with various structures and asphalt is essential to promote the wide adoption of graphene modified asphalt for high-performance pavement engineering. Herein, the enhancement of modified asphalts with nano-sized graphene (NG) and micro-sized graphene (MG) were systematically investigated by using dynamic shear rheometer (DSR), atomic force microscopy (AFM) and molecular dynamics (MD) simulation at multi-scale levels. The results demonstrate that MG can significantly enhance the deformation resistance and low-temperature crack resistance of modified asphalt, compare with NG, and AFM confirm that MG can obviously affect the rearrangement of four components in asphalt to form a micellar structure with higher modulus and lower energy dissipation. MD simulation further verifies that the higher mechanical strength of large-sized graphene modified asphalt is attributed to the reduced slide movement of cavitation structures in asphalt, since the larger graphene not only has stronger π-π interaction with asphaltene and resin, but also induces one more specific interaction of hydrogen bonds (O-H···S) between these polar components. The coupling interaction facilitates the formation of more compact micelles, resulting in the improved mechanical properties of asphalt. The elucidation of graphene size effect on asphalt provides encouragement for understanding the enhancement of graphene modified asphalt.

Laboratory evaluation of the effect of waste materials on mechanical properties of asphalt binder and mixture containing combined natural binder and waste polymer

The current study's objective is to examine the characteristics of waste polymer-incorporated natural binder modified binders and combinations. Recycling and making use of waste polymers has gained interest as a possible environmentally and financially responsible bitumen modification method. The goal of the current study was to explore the rheological and mechanical characteristics of mixes and bitumens modified with natural binder that contained various amounts of waste polymer. Original bitumen modified with 5%, 10%, and 15% weight of asphalt binder as well as varied amounts of RPW (3%, 5%, and 7% weight), were all employed as samples of bitumen in the study. Several asphalt binder tests such as conventional tests and rheological ones were performed on binder samples. The results showed that adding waste polymer to the natural binder modified binders enhanced their high-performance temperature, as seen by the decreased penetration and increased softening point values. Results revealed that binders containing 5%, 10% and 15% gilsonite have fatigue life at 2.5% strain about 1.06, 9, and 9.8 times higher than original binder, respectively. Results revealed that addition of 5%, 10% and 15% gilsonite leads to decrease the Jnr value by 36%, 87%, and 96%, respectively. While addition of 3%, 5%, and 7% RPW leads to increase the fatigue life by 1.12, 3.75, 5 times higher than 5% gilsonite modified asphalt. Additionally, the binders treated with waste polymers performed better at low temperatures as seen by their decreased stiffness and enhanced fracture resistance. However, a substantial proportion of waste polymer caused both low and high temperature performance to decline. Overall, this study indicates that waste polymer has the ability to enhance the performance characteristics of naturally occurring binder modified binders, but it is important to carefully evaluate the ideal waste polymer percentage in order to obtain the required performance advantages.

Experimental Investigation of LDPE and EVA on Asphalt Binder

Abstract: This research study aims to investigate the impact of incorporating Ethylene Vinyl Acetate (EVA) and Low-Density Polyethylene (LDPE) on the properties of asphalt binder. The use of polymer-modified asphalt binders has gained significant attention in recent years due to their potential to improve the performance and durability of asphalt pavements. EVA and LDPE are two commonly used polymers that have shown promise in enhancing the rheological and mechanical properties of asphalt binders. The experimental investigation involved the preparation of asphalt binder samples with varying percentages of EVA and LDPE, ranging from 0% to 8% by weight. A series of laboratory tests were conducted to evaluate the effects of polymer modification on the fundamental properties of asphalt binder. These tests included penetration, softening point, ductility, viscosity, and dynamic shear rheometer (DSR) tests.The results of the study indicated that the addition of EVA and LDPE led to notable improvements in the rheological and mechanical properties of asphalt binder. Increased polymer content resulted in reduced penetration values, higher softening points, and improved resistance to rutting and deformation. Additionally, the modified binders exhibited enhanced viscosity and elastic behavior, as indicated by the DSR tests. The study also investigated the compatibility between EVA/LDPE and asphalt binder through microscopy and chemical analysis techniques. The findings of this experimental investigation contribute to the understanding of the effects of EVA and LDPE on asphalt binder performance. The results highlight the potential of these polymers in enhancing the resistance to rutting and deformation of asphalt pavements. This research can serve as a basis for further studies on polymer modification of asphalt binders and aid in the development of improved asphalt pavement materials with enhanced durability and longevity.

Physico-chemical and mechanical properties of asphalt binders blended with waste bio-shell powder

ABSTRACT Bio-shell is a renewable bio-waste resource being used to develop sustainable and environmentally friendly pavement materials. In this study, bio-shell was mixed with asphalt to prepare bio-shell-modified asphalt. The modified asphalt was divided into four groups with 0%, 5%, 10% and 15% of waste bio-shells. The morphology of the bio-shell was investigated by scanning electron microscopy tests. Penetration, softening point, and ductility tests were performed to analyse the basic physical properties of bio-shell asphalt. Dynamic shear rheometer and bending beam rheometer were used to high and low-temperature rheological properties of the bio-shell-modified asphalt. Fourier transform infrared spectroscopy and nuclear magnetic resonance hydrogen spectroscopy were used to analyse the atomic distribution and relative content of bio-shell-modified asphalt and reveal the modification mechanism. Atomic force microscopy was employed to observe the nano-microscopic morphology of the bio-shell-modified asphalt, and to analyse the changes of the bee structures in the asphalt. The results showed that the high-temperature rheology of 15% bio-shell asphalt was the best. The rutting factors of the asphalt increased by 38%, 43%, 45%, 50%, 55% and 63% at temperatures of 40°C, 46°C, 52°C, 58°C, 64°C and 70°C, respectively, compared to the matrix asphalt.

An Investigation on the Effect of Aging on Chemical and Mechanical Properties of Asphalt Binders

An Investigation on the Effect of Aging on Chemical and Mechanical Properties of Asphalt Binders

Investigating the relationship between chemical composition and mechanical properties of asphalt binders using atomic force microscopy (AFM)

As a complex mixture, the composition-structure-mechanics relationship of asphalt binders is not well-understood. Thus, it is essential to understand the relationship between chemical composition and mechanical properties. Saturate, aromatic, resin and asphaltene (SARA) fractions are crucial chemical components of asphalt binders. At present, the main challenge faced by many researchers is the relationship between the SARA fractions and the microstructure, and how the SARA fractions affect the micro-mechanical properties of asphalt binders. In this paper, the composition-structure-mechanics relationship were studied using atomic force microscopy. The asphalt samples were divided into two groups. Firstly, different kinds of asphalt binders with different SARA content were compared. Then, new asphalt binders were derived and their properties were analyzed. Results show that bee structure appears on the surface of asphalt binders with higher asphaltene and resin contents, it means that the formation of bee structures is related to the aggregate of asphaltene and resin. Moreover, the micro-mechanical properties of the asphalt binders are affected by two fractions rather than a single fraction. The adhesion force increases with the increase in saturate and aromatic contents, and decreases with the increase in asphaltene and resin contents. The Derjaguin–Müller–Toporov (DMT) modulus, storage and loss modulus increase with the increase in asphaltene and resin contents, and decreases with the increase in saturate and aromatic contents. Furthermore, SARA fractions have the same effect on both the micro- and macro-rheological properties of asphalt binders. These findings will help to improve the understanding of the composition-structure-mechanics relationship of asphalt binders, which in turn will aid in optimizing their performance.

Morphological, Thermal, and Mechanical Properties of Asphalt Binders Modified by Graphene and Carbon Nanotube

Morphological, Thermal, and Mechanical Properties of Asphalt Binders Modified by Graphene and Carbon Nanotube

Biochar effects on the performance of conventional and rubberized HMA

Biogenic carbon made from biomass waste (referred to as Biochar here) has shown to enhance rheological and mechanical properties of asphalt binder. This paper presents the results of using biochar as an additive in Hot Mix Asphalt (HMA). The Semi-Circular Bend (SCB) test and the Hamburg Wheel Tracking (HWT) test were selected to analyze the resistance to fracture and rutting, respectively. Also, the resistance to colour degradation of HMA was evaluated using the Xenon Arc Test. The SCB test results suggested that biochar's presence led to an increase of strain energy and subsequently higher resistance to fracture. HWT test results showed that biochar's presence reduced total permanent deformation after 20,000 cycles and subsequently enhanced resistance to rutting. As for the resistance to colour degradation, biochar's addition helped preserve colour and decrease the surface degradation of the asphalt mixture exposed to solar radiation compared to the control mixture.

Laboratory Evaluation of Mechanical Properties of Modified Asphalt and Mixture Using Graphene Platelets (GnPs).

Recently, nanomaterials have attracted attention in the field of pavement construction as modifiers to endure heavy loads and climate changes. In this study, conventional asphalt (bitumen) of penetration grade AC (60/70) was modified with graphene platelets (GnPs) at three different contents: 0.5%, 1.0%, and 1.5% by weight of asphalt content. Kinematic viscosity, softening point, penetration, and dynamic shear rheology tests were performed to evaluate the mechanical properties of modified binder. The results showed that adding GnPs improves the mechanical properties of asphalt binder; the kinematic viscosities, softening points, and rutting parameters increased but penetrations decreased with the contents of GnPs. Hot mix asphalt specimens with GnPs-modified asphalt were prepared and characterized with Marshall tests, thermal stress restrained specimen tests (TSRST), wheel tracking tests, and indirect tensile tests. Similar to the results of asphalt binder, the mechanical properties of asphalt mixture were improved by GnPs. Marshall stability increased by 21% and flow decreased by 24% with accepted value of 2.8 mm in penetration when the mixture was modified with 1.0 wt% of GnPs. At the same GnPs content, modified asphalt mixture led to lower failure temperature by 2 °C in comparison with unmodified asphalt mixture and the cryogenic failure stress was improved by 12%. The wheel tracking tests showed that GnPs-modified asphalt mixture has outstanding deformation resistance in comparison with unmodified asphalt mixtures: after 5000 cycles, 1.0 wt% of GnPs reduced the rut depth of asphalt mixture by 60%—the rut depth of unmodified asphalt mixture was 6.9 mm compared to 2.75 mm for modified asphalt mixture. After 10,000 cycles, the modified asphalt mixture showed rut depth of 3.24 mm in comparison with 8.12 mm in case of unmodified asphalt mixture. Addition of GnPs into asphalt mixture significantly improved the indirect tensile strength: 1.0 wt% of GnPs increased the indirect tensile strength of unmodified asphalt mixture from 0.79 to 1.1 MPa recording ~40% increment. The results of this study can confirm that graphene platelets enhance the mechanical properties of asphalt mixture and its performance.

Comparing Micro- and Macro-Level Rheological Properties of Polymeric and Reclaimed Asphalt Pavement-Modified Asphalt Binders

Multi-scale evaluation of the rheological and mechanical properties of asphalt binder has substantial importance in understanding the binder’s micro- and macro-scale properties. This study compares the macro- and micro-scale mechanistic properties of asphalt binders. Test samples used in this study include performance grade binders (PG 64-22) from two different sources along with their modified counterparts. The modifiers include polyphosphoric acid (PPA), styrene-butadiene-styrene (SBS), a combination of SBS and PPA, and reclaimed asphalt pavement. To achieve the goal of this study, atomic force microscope technology was utilized to estimate the asphalt binder’s micro-mechanical properties (e.g., Derjaguin, Muller, Toropov modulus and deformation). On the other hand, data on the macro-scale properties—such as rutting factor (G*/sinδ), consistency and penetration—of the selected binders were analyzed and compared with the aforementioned micro-level properties. The comparative analyses indicated that the micro-mechanical properties of asphalt binders followed a linear trend with the macro-scale properties. The findings of this study are expected to help researchers and pavement professionals in modeling asphalt materials when multi-scale effects are deemed to be necessary.

Enhancing the Functional and Environmental Properties of Asphalt Binders and Asphalt Mixtures Using Tourmaline Anion Powder Modification

Due to its good piezoelectric and thermoelectrical properties, tourmaline anion powder (TAP) can be used as a potential modifier to improve the piezoelectric, thermoelectric, rheological, and mechanical properties of asphalt binders and asphalt mixtures, respectively. This study was conducted to investigate the functional, piezoelectric, and thermoelectric properties of a TAP-modified asphalt binder (TAPMA) and the corresponding asphalt mixtures. In the study, the TAPMA’s environmental friendliness, such as the volatile organic compound (VOC) adsorption and metal immobilization, were investigated. Compared to TAP at 3.95 pC/N, the piezoelectric constant of TAPMA was found to be 3.42 pC/N. In general, the results indicated that TAP could potentially improve the functional properties of asphalt binders and asphalt mixtures, including the piezoelectric and thermoelectrical properties. With respect to environmental enhancement, the asphalt binder VOC emission reduced to 50% after TAP addition. In terms of metal immobilization, the heavy metals Fe and Ti exhibited the best stability followed by the alkali metals Li, K and Na, and lastly, Ca and Mg, respectively. Nonetheless, the emission concentrations of all the metals were below the regulatory threshold. Furthermore, the study findings also indicated that TAPMA can potentially adsorb the tail gas emissions of vehicles and heavy metals.

Effects of bamboo fiber on the mechanical properties of asphalt mixtures

Fiber addition could enhance the permanent deformation and crack resistance of the asphalt mixture. Previous research has found the effect of fibers on asphalt mixtures, while bamboo fibers have been overlooked. Bamboo fibers involve strength and toughness properties, and the addition of bamboo fibers is significant for studying the improvement of the mechanical performance in asphalt mixtures. In this paper, the reinforcing effects of bamboo fiber on the mechanical properties of asphalt binders and mixtures are investigated under various loading and temperature conditions. Bending beam rheometer tests and frequency sweep tests using dynamic shear rheometer were conducted in this study to characterize the relevant properties of asphalt binder with different fiber contents. A Superpave gyratory compactor was used to produce asphalt mixture specimens with 0.3% bamboo fiber. In addition, dynamic modulus, stress sweep rutting, and cyclic fatigue tests were conducted to investigate the mechanical properties of the test specimens. The results indicate that the high-temperature shear strength and low-temperature flexibility of the asphalt binders were improved by the inclusion of bamboo fiber. The inclusion of only 0.3% bamboo fiber improved the rutting resistance and fatigue life of the asphalt mixtures. In general, the dynamic modulus values of the asphalt mixtures increased and the phase angles decreased with the addition of bamboo fiber. The performance test results show that the inclusion of bamboo fiber enhances the stiffness and cracking performance of asphalt mixture at the intermediate temperature, but the improvements are not significant at high temperature. The research could evaluate the mechanical properties of bamboo fiber asphalt mixtures, and provide a reference for the engineering application of bamboo fiber in asphalt mixtures.

Evaluation of workability and mechanical properties of asphalt binder and mixture modified with waste toner

In recent years, disposal of bulk quantity of waste toner generated from the manufacturing process, copying machines, and laser printers has been a huge problem. In this study, an attempt has been made to overcome these problems by incorporating the waste toner in asphalt mixtures in a proper proportion. This study aims to evaluate the effect of varying dosages (4%, 8%, 12%, and 16%) of waste toner on workability and mechanical properties (rutting and moisture-induced damage) of asphalt mixtures. Workability properties were evaluated using densification indices (Locking point method) and viscosity test. Rutting properties were evaluated using the wheel tracking device and multiple stress creep recovery tests. Moisture-induced damage properties were evaluated using indirect tensile strength (Modified Lottman) and bitumen bond strength test. Results show that the addition of waste toner makes asphalt binder stiffer, reduces moisture susceptibility, and pumping ability. Furthermore, the addition of waste toner reduces workability and resistance to moisture-induced damage properties but increases resistance to rutting properties of asphalt mixtures irrespective of dosage rate.

Laboratory Investigation of the Effect of Ceramic Fiber on Stone Matrix Asphalt Rutting Performance

Rutting is one of the most important distresses in asphalt mixed pavement. As for flexible pavements, stone matrix asphalt is the best option for reducing this failure despite its demerits, e.g., the risk of draining down and fat spots. There are several ways to decrease rutting potential, including by the use of fiber as asphalt binder modifier or asphalt mixture additive. Accordingly, in this study, the rheological and mechanical properties of asphalt binder and stone-matrix asphalt were examined at different percentages of ceramic fibers as an asphalt binder modifier. A rolling thin-film oven test was conducted to simulate the short-term aging of asphalt binder and obtain a binder that has reliable similarity to binders found in the field. Also, a dynamic creep test was performed at 40°C and 60°C at two stress levels (100 and 300 kPa), and a dynamic shear rheometer test was conducted at 58°C, 64°C, 70°C, and 76°C. The results revealed that the use of 3% and 5% ceramic fibers results in the best performance in terms of reducing the potential of rutting in stone-matrix asphalt. The results obtained in terms of the rheological properties of asphalt binder based on the dynamic shear rheometer test also showed that the incorporation of ceramic fibers increased the rutting parameter (G*/sinδ) of asphalt binder. Moreover, the results of statistical tests indicated that the use of ceramic fibers up to 3% in all the utilized stone-matrix asphalt samples improved the performance against rutting.

Towards the Valorization of Phosphate Wastes in bituminous materials

The phosphate production process generates millions of tons of wastes annually in Morocco. These mine tailings could have negative impacts that can be observed on the surrounding environment. Therefore, innovative strategies should be proposed to valorize the solid wastes. This paper investigates a new approach of phosphate waste valorization in producing asphalt mixtures which can be a cost-effective and eco-friendly solution for managing these wastes. The main goal of the presented study is to examine the feasibility of using three phosphate wastes for fabrication of bituminous materials and to discover the better waste to be added in asphalt mixtures. Many solid wastes are selected to be used as minerals fillers. it is showed that the viscous flow behavior of the asphalt binder containing phosphogypsum and fly ash wastes is substantially improved in compression of that of asphalt binder with phosphate sludge filler. In addition, it was observed that phosphogypsum waste can enhance the mechanical properties of asphalt binder as well as its performance against rutting in comparison to the others wastes.

Fatigue evolution characteristic and self-healing behaviour of asphalt binders

ABSTRACT The self-healing ability of asphalt material has a significant effect on improving fatigue life of asphalt pavement. The objective of this paper was to investigate the stage characteristics of fatigue damage of asphalt binder and its associated self-healing behaviours. Firstly, the rheological behaviour and fracture surface morphology were discussed to investigate the fatigue evolution characteristics of asphalt binders. Secondly, an effective method for interpreting the self-healing capability of asphalt binder at different fatigue stages was proposed by conducting fatigue-healing-refatigue tests and Fourier transform infrared spectroscopy analysis. Finally, the effect of temperature on the self-healing properties of different aging asphalt binders at different fatigue damage stages was explored. The results show that the stage characteristics of fatigue damage of asphalt binders could be distinguished effectively by correlating complex shear modulus with ratio of dissipation energy change under load time history. The fatigue cracking morphologies of asphalt binders under cyclic shear loading are susceptible to the aging degree of asphalt binder. An index associated with initial dissipative energy and number of cycles could effectively evaluate the self-healing properties of different aging asphalt binders. After the occurrence of macrocracks, the mechanical properties of asphalt binder cannot be completely restored by increasing the temperature.

Study the Effect of Mineral Filler on the Mechanical Properties of Hot Mix Asphalt

The important component in the asphalt mixture is mineral filler materials as it plays an essential part in the stiffening and toughening of asphalt binder. In addition, the mechanical properties of asphalt binder are influenced by the mineral filler, and significantly affected with respect to stripping or moisture susceptibility. This paper is displayed the mechanical properties of asphalt mixtures that used asphalt binder grade (40-50), the gradation of aggregates selected with the mid-point according to the Iraqi specification and two types of mineral filler materials (High Reactivity Attapulgite (HRA) and Portland Cement (PC)) according to the empirical requirements. The mixtures are produced and compacted according to the Marshall Mix design method. In addition, this paper is displayed the positive influence of HRA and PC in the asphalt mixtures such as (Volumetric Properties, Marshall Properties, Marshall Stiffness, the Indirect Tensile Strength and Moisture Susceptibility). The results explained that the (5%) and (7%) HRA had an important influence on the properties of asphalt mixtures. With the increment in the percentages of HRA, the volumetric properties of asphalt mixtures enhanced. Laboratory investigation results support the advantage of adding HRA to the asphalt mixtures. HRA as an active mineral filler has good resistance to moisture sensitivity and mechanical properties, which contributes to extending the life cycle of the pavement layer.

A performance characteristic models of properties of dissolved plastic bottle modified bitumen for hot mix asphalt production

This paper investigated the effect of recycling Polyethylene Terephthalate (PET) waste bottles in dissolved (liquid) miscible forms (1, 3, 5, 7, 9, 11, 13, 15 and 17% by the weight) on the properties of standard straight-run grade bitumen. Classification, strength & safety compliance properties were carried out, according to provisions of standard testing procedures, at different percentages of (0-17) dissolved PET. Quantitative explanation of models for the trend of the variation of these properties were developed for each property with respect to % PET. Models were later compared with the corresponding statistic. The developed models for ductility, penetration, softening point, viscosity, flash and fire points, and specific gravity of the modified bitumen were -2.185(%PET) + 79.399, 2.456(%PET) + 47.401, -3.149(%PET) + 92.909, 1.244(%PET) + 75.622, 2.6801(%PET) + 254.69, 2.2036(%PET) + 307.65 and 0.0042(%PET) + 0.9589 with R2 values of 0.976, 0.969, 0.992, 0.976, 0.9917, 0.9774 and 0.9881 respectively. Results revealed that addition of PET (0 – 17 %) increased the softening, viscosity, specific gravity, flash and fire points of bitumen but decreased the penetration and ductility. It is concluded that PET can be used to improve the classification properties only but less for the mechanical properties of asphalt binder. However, satisfactory values which are in conformity with Nigerian, American and British standard specifications can be met at % PET of ≥2.01, ≥3.52, 11.09 – 14.58, 4.92 – 9.20, ≥1.98, ≥5.60, and ≥9.79 for ductility, viscosity, softening point, penetration, flash point, fire point and specific gravity respectively.