Properties Of Asphalt Cement Research Articles

Influence of Thermoplastic Polyurethane on the Properties of Asphalt Cement and the Elastic Behavior of Asphalt Mixtures

The useful life of pavements determines the design of asphalt mixtures. However, premature structural failures and low durability are one of the main problems in pavement engineering today. The action of loads produced by traffic, exposure to environmental factors and the inadequacy of conventional designs of asphalt pavements are some of the main problems associated with the durability of the pavement. The modification of asphalt binders is an alternative that has been used for some years to improve the properties of bituminous material. Among the modifying materials are elastomers, a class of polymers with elastic properties that can be heat-treated. In this study, the asphalt was modified by wet means by adding 5, 10 and 15% of Thermoplastic Polyurethane (TPU) by weight of the binder. Subsequently, standard samples were prepared with the characterized constituents and mixtures with the modified asphalt cement. Consequently, tests were carried out to obtain the optimal mixture that improves the properties of conventional pavement. The results show that the optimal TPU addition content is 5%. With this percentage, the modified binder presented a greater elastic recovery of up to 5.60% and a reduction of up to 42.6% in penetration compared to conventional asphalt. In addition, using the Marshall method, it was determined that the stability of the modified mixtures was much higher than that of standard mixtures for light, medium and heavy traffic; so, they will have a higher resistance to deformation and better fatigue behavior.

Effect of nano-TiO2 on physical and rheological properties of asphalt cement

Abstract In recent years, nano-modified asphalt has gained significant attraction from researchers in the design of asphalt pavement fields. The recently discovered Titanium dioxide nanoparticles (TiO2) are among the most exciting and promising nanomaterials. This study examines the effect of 1, 3, 5, and 7% of nano-TiO2 by weight of asphalt on some of its rheological and hardened properties. The experimental study included physical and rheological properties. The asphalt penetration, softening point, ductility, and rotational viscometer tests indicate that 5% nano-TiO2 is the ideal amount to be added to bitumen as a modifier. The study of the rotating viscosity test showed that the addition of nano-TiO2 helped to increase viscosity and lessen bituminous sensitivity. Rutting factor in terms of G*/sin δ indicated the addition of 3 to 7% of nano-TiO2 increased the rutting resistance of asphalt against higher temperatures and promoted performance grade by about one grade at 3% and two grades at a range of 5–7% this suggests that nano-TiO2 increased the stiffness of the asphalt and leading to enhance the rutting performance of asphalt. While fatigue parameter, G*.sin δ shows that as nanocontent increases, higher stiffness at 5 and 7% of TiO2 content leads to an increase in complex modulus and a decrease in fatigue parameter. Higher creep stiffness and higher m-values were noted at low temperatures as nano increases in asphalt binder, increasing stiffness and decreasing the m-value at −6 and 12°C. As a result, using 5% nano-TiO2 will improve asphalt’s physical properties and enhance asphalt anit-rutting and fatigue resistance.

Effect of Waste Tire Rubber on Properties of Asphalt Cement and Asphalt Concrete Mixtures: State of the Art

AbstractThis research paper aims at providing a comprehensive analysis of the effect of the addition of waste tire rubber to asphalt mix and its properties. Having reviewed several published research papers, it is concluded that the addition of waste tire rubber to asphalt mix increases the softening point, viscosity, flow, void mineral aggregate (VMA), and Marshall stability. On the other hand, it reduces the penetration, ductility, specific gravity, flash point, and retained stability. It is stated also that the addition of waste tire rubber to asphalt mix is a safe way of managing huge amounts of waste tires generated around the world in a high-value reuse.

Monitoring the Rheological Properties of Asphalt Cement after Digestion with Micro and Nano Size Additives

Monitoring the Rheological Properties of Asphalt Cement after Digestion with Micro and Nano Size Additives

Effect of waste plastic polyethylene terephthalate on properties of asphalt cement

Effect of waste plastic polyethylene terephthalate on properties of asphalt cement

Assessment of Modified - Asphalt Cement Properties

The Asphalt cement is produced as a by-product from the oil industry; the asphalt must practice further processing to control the percentage of its different ingredients so that it will be suitable for paving process. The objective of this work is to prepare different types of modified Asphalt cement using locally available additives, and subjecting the prepared modified Asphalt cement to testing procedures usually adopted for Asphalt cement, and compare the test results with the specification requirements for the modified Asphalt cement to fulfill the paving process requirements. An attempt was made to prepare the modified Asphalt cement for pavement construction in the laboratory by digesting each of the two penetration grade Asphalt cement (40-50 and 60-70) with sulfur, fly ash, silica fumes. Three different percentages of each of the above mentioned additives have been tried using continuous stirring and heating at 150 ºC for 30 minutes.
 The prepared modified Asphalt specimens were subjected to physical properties determination; the penetration, softening point, ductility before and after laboratory aging. It was concluded that all percentage of additives has reduced the penetration value of asphalt cement, an exception to that could be noticed when using asphalt cement (40-50) and when adding sulfur. Softening point was increased with the addition of all percentage of additives except that with 7% sulfur by wt. of asphalt cement (40-50) it decreased by 8%.
 After aging in general, the penetration decreased by about 37% for control specimens and the softening point increased by about 8% for control specimens.
 For asphalt cement 40-50 after aging, Sulfur has the least impact on ductility since it reduces it by 20%. Silica fumes have moderate effect on ductility when it reduces it by 35%, while fly ash shows the highest impact of 36%.
 For asphalt cement 60-70 after aging, sulfur was able to almost retain its ductility, while fly ash shows moderate reduction in ductility within a range of 20-36% and silica fumes shows high impact on ductility in the range of 30-50%.

THE IMPACT OF CRUMB RUBBER CONTENT ON THE RHEOLOGICAL FEATURES OF ASPHALT CEMENT

Asphalt modified with reused rubber from vehicle tires was considered subject to a severe challenge in two directions, the first is the possibility of waste disposal to maintain sustainable infrastructure, and the second is the clear and tangible ability to enhance the characteristics of asphalt mortars and mixes. The need for asphalt cement and mixtures improvement has become unavoidable as a result of the main failure sorts related to the flexible pavement, which are represented by the cracking and rutting, that result from fatigue in the road due to the excessive application of loads and the high tire pressures of vehicles nowadays. The binder may be able to lessen asphalt paving issues and enhance the pavement's overall functionality. Following up on earlier research, it was found that rubber is one of the key components in enhancing the durability and temperature tolerance of modified asphalt cement. The aim of this study is to track the improvement in the rubber-modified asphalt binder as it was observed that the introduction of tire fracture rubber improved the quality of asphalt cement in addition to increasing the cracking factor (G*/Sin), which indicates a greater resistance to cracking. Furthermore, it is believed that the use of rubber crumbs to enhance the properties of asphalt cement will improve the sustainability of asphalt pavement economically and environmentally.

Effect of Hot Glue Additive on the Rheological Properties of Asphalt Cement and Mixtures Performance

In general, the physical and rheological properties of asphalt binder are directly affecting the resistance of asphalt mix to the permanent deformation (rutting), water damage, and thermal cracking. The degradation in these properties leads to severe distresses that appear in the pavement and, consequently, make the repair and maintenance very expensive. Since the modified-asphalt cement may help to minimize such aforementioned distresses, this research is established for this purpose. It aims to investigate the physical and rheological properties of modified-asphalt cement with silicone, dense silicone rubber, and ethylene propylene diene monomer rubber. Five contents for each type of hot glue are investigated; 0.4, 0.8, 1.2, 1.6, and 2% of the asphalt cement weight. Conventional asphalt cement tests such as penetration, softening point, dynamic viscosity, and ductility tests are conducted to evaluate the hot glue-modified asphalt cement properties. Moreover, the Marshall and indirect tensile strength tests are conducted to examine the effect of hot glue on the performance of the asphalt mixtures at concentrations of 0.8 and 1.6% of the asphalt cement weight. The results show that the hot glue-modified asphalt cement leads to an increase in the hardness and consistency, and a reduction in the temperature susceptibility of asphalt cement. These features lead to better Marshall stability and tensile strength ratio, as compared with the standard asphalt cement mixture.

Evaluation of the physical and rheology properties of rubberized asphalt cement

Asphalt cement is a viscoelastic substance that operates like an elastic solid at low service temperatures or under rapid loading. Whenever loaded slowly or at high temperatures, it behaves like a viscous liquid. This classic duality necessitates enhancing the efficiency of an asphalt binder to decrease stress cracking at cold temperatures (fatigue) and plastic deformation at hot temperatures (rutting). The use of polymer-modified asphalt binder is one solution for satisfying today's pavement performance standards. The purpose of this study was to determine the impact of asphalt cement modifiers on the physical and rheological properties of asphalt cement. This study used asphalt cement with a penetration grade of 40-50, modified with styrene-butadiene rubber (SBR) at four different levels of modification, specifically 0%, 2%, 4%, and 6% by weight of asphalt cement. Depending on Rotational viscosity and dynamic shear rheometer, and the traditional test. The mixes modified with SBR polymer showed enhanced physical and rheology characteristics, with decreased penetration and ductility and increased viscosity and softening point, as well as a lower rutting factor, indicating an increase in rutting resistance, according to the experimental data. The performance grade for original asphalt cement was 64-16, and for SBR at 2% additive, the original PG was improved to PG70-16. Adding 4% additive to asphalt cement improved the performance grade to PG76-16, and using 6% increased the performance grade to PG82-16.

Toward a realistic asphalt mix ageing protocol

The time-associated changes of the asphalt cement properties significantly impact the performance and durability of pavements. Different techniques have been introduced to simulate pavement ageing, most of which use elevated temperatures and neglect factors such as moisture and solar radiation. This research evaluated the coupling effect of solar radiation, heat, and moisture conditioning on the laboratory compacted plant mixes to achieve representative aged samples for performance testing. Rheological and chemical analysis were then performed on samples at various stages of the conditioning process and recovered asphalt cement. Temperature-Sensitivity of the rheological parameters were evaluated using time-temperature superposition shift factors. Carbonyl and sulfoxide indices and carbonyl to sulfoxide ratios were used to assess the kinetics of the age-related chemical changes. This study showed that coupling moisture and solar radiation could alter the chemistry and rheology of conditioned samples.

Effect of Waste Oil Shale Ash on Properties of Asphalt Cement and Asphalt Concrete Mixtures: State of the Art

Effect of Waste Oil Shale Ash on Properties of Asphalt Cement and Asphalt Concrete Mixtures: State of the Art

Impact of Nano Materials on the Properties of Asphalt Cement

Impact of Nano Materials on the Properties of Asphalt Cement

Evaluating The Effects of Micro and Nano Size of Silica Filler on Asphalt Cement Properties

This research study examines the practicability of using micro and nano size silica to improve the asphalt characteristics. Asphalt cement penetration grade of (60 /70) was prepared using (0%, 2%, 4% and 6%) of silica filler by weight of asphalt and investigated in terms of the softening point, penetration, and penetration index, viscosity, and ductility values. To modify the asphalt binder, the silica powder was mixed by a mechanical blender set at (2000) rpm at a mixing temperature of 140°C. However, the main challenge is an agglomeration of nano-silica powder which can reduce the ductility of nano silica modified binder. Therefore, this paper studies the efficiency of mixing period to obtain a homogeneous composite binder while alleviating the agglomeration issue. To do so, the effect of periods of mixing ranged between (30 to 60) minutes were examined on characteristics of modified asphalt binders. Overall, the addition of silica filler has an encouraging impact on the asphalt binder rheological properties. Also, the ductility value decreases with the addition of nano-silica content, attributed to the huge surface area and degree of agglomeration. Furthermore, results exhibited that 6% of micro silica powder and 4 % of nano silica powder were reasonable to develop the rheological properties.

Effect of olive waste ash on properties of asphalt cement and asphalt concrete mixtures

In this study, the effect of olive waste ash on the properties of asphalt cement and asphalt concrete mixtures was investigated. Asphalt cement with (80/100), limestone and valley gravel aggregates, and olive waste ash were used. Five asphalt binder levels with (0, 5, 15, and 20) percentages of olive waste ash (OWA) by volume of asphalt-ash binder were performed to investigate the effect of OWA on the physical properties of the asphalt-ash binder. Penetration, softening point, ductility, fire and flash point, and the specific gravity were performed on the binder. Five levels of asphalt-ash binders were used to investigate the Marshall specimens and the dynamic creep tests. These tests were performed at three testing temperature (20, 30, and 40°C) and three load frequency levels (1.0, 4.0, and 8 Hz). The results showed that penetration and ductility inversely related, while, specific gravity, softening point, fire and flash point were directly related to the increase in OWA content. For both aggregates of asphalt concrete mixtures, as the percentage of ash increasing, unit weight and flow were decreased for the same volume of asphalt-ash binder content for each type of aggregate, while, as the percentage of OWA increased, voids in mineral aggregate and air voids were increased for the same volume of asphalt-ash binder content for each type of aggregate. Marshall Stability increased up to 10% of OWA, over that the stability decreased. The retained Marshall stability ratio increased with increasing ash, while the dynamic modulus was decreasing with increasing the percentage of OWA content, testing temperature, and loading frequency for both aggregates.

Probing the modification mechanism of and customized processing design for SBS-modified asphalts mediated by potentiometric titration

Styrene-butadiene-styrene (SBS)-modified asphalt plays an integral role in asphalt pavements. To facilitate the understanding of the correlations between the physical and chemical properties of asphalt cement and SBS, a method for the direct quantitative determination of the SBS modification mechanism via potentiometric titration is proposed. This method will theoretically guide the processing design of SBS-modified asphalts. Potentiometric titration is applied to investigate the unsaturation of SBS-mixed, SBS-modified, and SBS/sulfur-modified asphalts with different SBS dosages ranging from 0% to 10%. The unsaturation of SBS-mixed asphalt exhibits a good linear increase with an increase in SBS dosage. A noticeable loss of SBS unsaturation occurs in SBS- and SBS/sulfur-modified asphalts after undergoing complete modification. In addition, unsaturation presents an evident inflection point at approximately 5 wt% SBS with an increase in SBS dosage. This finding indicates SBS changing from a dispersed phase to a continuous phase in the modified asphalts. Remarkably, the addition of sulfur can accelerate the emergence of an inflection point. Results corroborate that various types of virgin asphalt exhibit different inflection points. SBS/sulfur-modified asphalt demonstrates stronger chemical cross-linking than SBS-modified asphalt. These findings are further confirmed via fluorescence imaging, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Potentiometric titration potentially provides a direct quantitative method for probing the modification mechanism of and designing customized processing for SBS-modified asphalts.

Evaluation of elevated temperature properties of asphalt cement modified with aluminum oxide and calcium carbonate nanoparticles

Higher temperature properties of the asphalt cement have been characterized before and after modification using dynamic shear rheometer (DSR) and viscosity testing. In this study, calcium carbonate nanoparticles (CaCO3) and aluminum oxide nanoparticles (Al2O3) have been added to the base asphalt cement with concentrations of 3, 5 and 7%.wt by the weight of the asphalt cement. The increase of CaCO3 and Al2O3 content has significant effect on the properties of asphalt cement. The viscosity of the modified asphalt cement increased up to 90 and 108% respectively compared to the base asphalt cement. In addition, the results showed that both modifiers have great storage stability and compatibility at elevated temperature. The evaluation of the rheological properties of asphalt cements revealed that the stiffness of the modified samples improved with additional increase of the modifier concentration of up to 5%, which indicates better resistance to rutting parameter. The enhancement was up to 388.89% for Al2O3 and 74.07% for CaCO3. As a result, the usage of CaCO3 and Al2O3 nanoparticles can be considered as appropriate alternative materials to modify asphalt cement.

The properties of nanosilica-modified asphalt cement

ABSTRACTThis study aimed to investigate some engineering properties of asphalt cement modified with different percentages of nanosilica. 60/70 Penetration grade asphalt cement was modified with different percentages of nanosilica (i.e. 1, 3, and 5 wt%) and their properties were evaluated. After evaluating the modified binder using scanning electron microscopy, the penetration grade, softening point, and ductility of the modified binder were measured. Using the penetration grade and softening point, the penetration index of the binders was determined. The results showed that the binder stiffness increases and the ductility and temperature sensitivity decreases with increasing nanosilica content.

CHARACTERIZATION OF THE PERFORMANCE OF ALUMINUM OXIDE NANOPARTICLES MODIFIED ASPHALT BINDER

This study investigates the physical and rheological properties of asphalt binders modified by nano aluminum oxide (AL2O3). Several conventional tests were conducted, including penetration, softening point and ductility, rotational viscosity and dynamic shear rheometer (DSR). Based on the results of the tests, it was found that the hardness of modified asphalt binders increased with the addition of nano AL2O3 up to 5%. As a result of the increased hardness, the softening point of modified asphalt improved compared with base asphalt binders. The rheological property of modified binders was enhanced at low and high temperatures. The results of a DSR test revealed that the G* were improved, whereas the δ decreased slightly. The addition of a different percentage of AL2O3 to base binder had a remarkable influence on resistance to permanent deformation (high temperature rutting and low temperature fatigue). Results recognize 5 wt.% as the optimum content of the modifier. Therefore, nano AL2O3 can be considered as a proper alternative additive to modify the properties of asphalt cement.

Physical and rheological properties of acrylate–styrene–acrylonitrile modified asphalt cement

Polymer-modified asphalt cement (PMAC) has been used in the last few decades to mitigate several root causes of asphalt-cement failures. Furthermore, it has been proved that polymers used as asphalt-cement modifiers had significant influence on the properties of asphalt at low and high temperatures. The primary objective of this study was to investigate the rheological, mechanical, and physical properties of acrylate–styrene–acrylonitrile (ASA) PMAC. Three types of samples with different concentration of the additives were studied, namely asphalt cement with 3%, 5%, and 7% of ASA. The influence of the modifier on the rheological, mechanical, and physical properties was evaluated by conventional tests (penetration, softening point, and ductility), viscosity, X-ray diffraction (XRD), and measurements from a dynamic shear rheometer (DSR). From the results of this study, it is evident that the addition of ASA has a significant effect on the rheological properties of asphalt cement. The temperature susceptibility of modified asphalt cement (MAC) was reduced compared with unmodified asphalt cement. In addition, the storage-stability test confirmed that the ASA–MAC has good compatibility. Furthermore, XRD results revealed that the phase of ASA–MAC changed from amorphous to semi-crystalline, which indicates that these materials have good workability. Based on the results from the DSR measurements, ASA–MAC has reduced temperature susceptibility, and increased stiffness and elastic behavior in comparison to unmodified asphalt cement. Moreover, ASA–MAC shows improved rutting resistance at high temperatures and higher fatigue performance at low temperatures. As a result, ASA can be considered as a proper alternative additive to modify the properties of asphalt cement.

Carbon Nanotubes-modified Asphalt Binder: Preparation and Characterization

This study focuses on the exploratory analysis of the mixing procedure of carbon nanotubes (CNTs) with asphalt cement (AC) and discusses the viscoelastic characteristics of neat and CNT-modified AC binders. Two CNT-asphalt cement mixing procedures including simple and wet processes were investigated. Viscoelastic properties of modified AC incorporated with 0.1, 0.5, and 1 (%w/w) CNT were evaluated, considering bitumen penetration, softening point, ductility, rotational viscosity (RV), and dynamic shear rheometer (DSR) tests, then the results were compared to those of unmodified asphalt binder. It was found that the wet process technique can make a homogeneous CNT-asphalt binder mixture, while the simple process technique would not disperse CNTs as uniformly as the wet process, but it is easier and more practical. Moreover, adding carbon nano tubes (CNTs) provides an enhancement of rutting resistance potential along with the resistance to thermal cracking.