Search

Overloading and climate change are often problems in pavement structures. For this reason, hard asphalt binders have high softening points, are elastic, and have good adhesion, which is needed to improve pavement performance. Asphalt binder performance can be enhanced by adding additives such as natural rubber or natural-rubber-modified asphalt. However, natural-rubber-modified asphalt shows poor storage stability problems. This is due to differences in density and viscosity between the constituent components of natural-rubber-modified asphalt. This study examines the phase separation mechanism in technically specified natural rubber (TSNR) modified asphalt. Prediction of the optimum storage length of modified asphalt before phase separation occurs, using a combined incompressible Navier–Stokes and phase field model and carried out with COMSOL Multiphysics software version 5.5. Experimental validation was conducted at TSNR levels of 8, 10, and 12% at 160 °C for 48 h, with and without sulfur. The simulation showed that the asphalt modified with TSNR experienced phase separation after 12 h of storage at 160 °C under conditions without stirring. This aligns with the experimental results, which showed phase separation at 160 °C after 48 h. Adding sulfur additives did not have much effect on improving storage stability. The combined incompressible Navier–Stokes and phase field model accurately describes the phase separation in TSNR-modified asphalt. The results of this research recommend that the industry store natural-rubber-modified asphalt in a constantly stirred condition to prevent phase separation of modified asphalt. In addition, the results of this research help the industry predict or increase the homogeneity of polymer-modified asphalt production and save time and costs. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis of mesophase pitch using low-cost fluid catalytic cracking (FCC) slurry and waste fluid asphaltene (WFA) as raw materials through the co-carbonization method. The resulting mesophase pitch product and its formation mechanism were thoroughly analyzed. Various characterization techniques, including polarizing microscopy, softening point measurement, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were employed to characterize and analyze the properties and structure of the mesophase pitch. The experimental results demonstrate that the optimal optical texture of the mesophase product is achieved under specific reaction conditions, including a temperature of 420 °C, pressure of 1 MPa, reaction time of 6 h, and the addition of 2% asphaltene. It was observed that a small amount of asphaltene contributes to the formation of mesophase pitch spheres, facilitating the development of the mesophase. However, excessive content of asphaltene may cover the surface of the mesophase spheres, impeding the contact between them and consequently compromising the optical texture of the mesophase pitch product. Furthermore, the inclusion of asphaltene promotes polymerization reactions in the system, leading to an increase in the average molecular weight of the mesophase pitch. Notably, when the amount of asphaltene added is 2%, the mesophase pitch demonstrates the lowest ID/IG value, indicating superior molecular orientation and larger graphite-like microcrystals. Additionally, researchers found that at this asphaltene concentration, the mesophase pitch exhibits the highest degree of order, as evidenced by the maximum diffraction angle (2θ) and stacking height (Lc) values, and the minimum d002 value. Moreover, the addition of asphaltene enhances the yield and aromaticity of the mesophase pitch and significantly improves the thermal stability of the resulting product. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract In a short-pulse CO2 laser based on discharge excitation, there is a pulse tail that depends on the device configuration and operating conditions. The pulse tail is longer than the spike pulse and causes thermal effects such as a crack, heat-affected zones (HAZ), and so on. There are various types of glass having different physical constants related to heat, such as the thermal expansion coefficient and the softening point. Even if the same CO2 laser pulse is radiated onto glass, the processing results may differ depending on the glass material. Four types of glass, namely, crown glass, soda-lime glass, borosilicate glass, and synthetic quartz glass were irradiated with two types of short CO2 laser pulses, one with a large pulse tail and one with a small pulse tail, at a repetition rate of 200 Hz and a fluence per pulse of 22 J/cm2. As the processing characteristics, the ratios of the surface hole diameter and the HAZ diameter to the irradiation diameter, as well as the drilling depth, were investigated. The pulse-tail energy of the short CO2 laser pulses did not affect the surface hole diameter. In the glasses with small softening points of 740 °C or less, the pulse-tail energy of short CO2 laser pulses affected the HAZ with a large number of pulse irradiations with a total irradiation fluence of 2000 J/cm2 or more. The short CO2 laser pulses with a small tail produced a smaller HAZ than the short CO2 laser pulses with a large tail. In drilling with a large number of pulse irradiations, the short CO2 laser pulses with a small tail produced deeper drilling than the short CO2 laser pulses with a large tail. The glass material did not affect the surface hole diameter and the drilling depth. The glass material affected the HAZ.

In a short-pulse CO2 laser based on discharge excitation, there is a pulse tail that depends on the device configuration and operating conditions. The pulse tail is longer than the spike pulse and causes thermal effects such as a crack, heat-affected zones (HAZ), and so on. There are various types of glass having different physical constants related to heat, such as the thermal expansion coefficient and the softening point. Even if the same CO2 laser pulse is radiated onto glass, the processing results may differ depending on the glass material. Four types of glass, namely, crown glass, soda-lime glass, borosilicate glass, and synthetic quartz glass were irradiated with two types of short CO2 laser pulses, one with a large pulse tail and one with a small pulse tail, at a repetition rate of 200 Hz and a fluence per pulse of 22 J/cm2. As the processing characteristics, the ratios of the surface hole diameter and the HAZ diameter to the irradiation diameter, as well as the drilling depth, were investigated. The pulse-tail energy of the short CO2 laser pulses did not affect the surface hole diameter. In the glasses with small softening points of 740 °C or less, the pulse-tail energy of short CO2 laser pulses affected the HAZ with a large number of pulse irradiations with a total irradiation fluence of 2000 J/cm2 or more. The short CO2 laser pulses with a small tail produced a smaller HAZ than the short CO2 laser pulses with a large tail. In drilling with a large number of pulse irradiations, the short CO2 laser pulses with a small tail produced deeper drilling than the short CO2 laser pulses with a large tail. The glass material did not affect the surface hole diameter and the drilling depth. The glass material affected the HAZ. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of East China University of Science & Technology is the property of Journal of East China University of Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Overloading and climate change are often problems in pavement structures. For this reason, hard asphalt binders have high softening points, are elastic, and have good adhesion, which is needed to improve pavement performance. Asphalt binder performance can be enhanced by adding additives such as natural rubber or natural-rubber-modified asphalt. However, natural-rubber-modified asphalt shows poor storage stability problems. This is due to differences in density and viscosity between the constituent components of natural-rubber-modified asphalt. This study examines the phase separation mechanism in technically specified natural rubber (TSNR) modified asphalt. Prediction of the optimum storage length of modified asphalt before phase separation occurs, using a combined incompressible Navier–Stokes and phase field model and carried out with COMSOL Multiphysics software version 5.5. Experimental validation was conducted at TSNR levels of 8, 10, and 12% at 160 °C for 48 h, with and without sulfur. The simulation showed that the asphalt modified with TSNR experienced phase separation after 12 h of storage at 160 °C under conditions without stirring. This aligns with the experimental results, which showed phase separation at 160 °C after 48 h. Adding sulfur additives did not have much effect on improving storage stability. The combined incompressible Navier–Stokes and phase field model accurately describes the phase separation in TSNR-modified asphalt. The results of this research recommend that the industry store natural-rubber-modified asphalt in a constantly stirred condition to prevent phase separation of modified asphalt. In addition, the results of this research help the industry predict or increase the homogeneity of polymer-modified asphalt production and save time and costs.

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the first article of this series, the influence of the preparation and heat treatment of heavy tar on the yield, softening point, degree of coking, and density of petroleum pitch was considered [1]. In the present article, the influence of the preparation of heavy pyrolysis tar on the group composition of the produced is studied. The influence of the group components on the coking properties and softening point of the pitch is considered. By adjusting the production conditions, the group composition of the pitch may be regulated, and pitch of specified quality may be obtained. [ABSTRACT FROM AUTHOR]

In this work, the effects of different fiber loadings on the mechanical properties of the composites at the sub-micron scale were studied through nanoindentation followed by physical characterization. The composites were prepared by incorporating different loadings of wheat straw, corn stalk, and rice husk in polypropylene copolymer using a melt processing method followed by thermal–hydraulic compression technique. Nanoindentation experiments in quasi-continuous stiffness mode were performed on the surfaces of produced composites to study the composites' elastic modulus, hardness, and creep properties. The obtained results expressed the in-depth study of the micro- and macro-level structure and behavior of particle interactions. The findings demonstrated that observable shifts in composites' hardness, elastic modulus, and creep rate had occurred. The WS-reinforced biocomposite sheet showed the highest elastic modulus of 1.09 and hardness of 0.11 GPa at 40 wt% loading in comparison to other loadings. An impact strength of 7.55 kJ/m2 was noted for the biocomposite at 40 wt% RH loading. In addition, optical microscopy, Fourier transform infrared spectroscopy, water absorption, thickness swelling, and Vicat softening point studies were conducted on biocomposite sheets to evaluate differences in physical, mechanical, and thermal properties. The outstanding mechanical performance of the newly developed composites makes them suitable for use as a biodegradable packaging material. [ABSTRACT FROM AUTHOR]

Coal tar pitch is important as a binder in the production of construction materials and as the raw material in the production of pitch coke. It is widely used, under the name of electrode pitch, as a binder in the production of electrodes and anode mass. Various modifications improve the characteristics of electrode pitch. In the present work, the practicality of modification by low-temperature thermal oxidation (up to 300°C) is considered. Specifically, experiments are conducted on the thermal oxidation of Altai Koks electrode pitch. The apparatus employed consists of a reactor, a compressor, and a heating system. The softening point, fractional composition, and yield of the oxidation products are determined. Low-temperature thermal oxidation permits the production of higher-quality electrode pitch. The duration of low-temperature thermal oxidation and the maximum temperature corresponding to increase in the softening point of the pitch are established. This outcome of oxidation is of great interest. The experiments show that the content of the α1 fraction does not increase in the low-temperature thermal oxidation of electrode pitch. The increase in softening point is associated with increase in the α2 fraction during oxidation. [ABSTRACT FROM AUTHOR]

Copyright of Karaelmas Science & Engineering Journal / Karaelmas Fen ve Mühendislik Dergisi is the property of Karaelmas Science & Engineering Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Twenty-two straight run vacuum residues extracted from extra light, light, medium, heavy, and extra heavy crude oils and nine different hydrocracked vacuum residues were characterized for their bulk properties and SARA composition using four and eight fractions (SAR-ADTM) methods. Intercriteria analysis was employed to determine the statistically meaningful relations between the SARA composition data and the bulk properties. The determined strong relations were modeled using the computer algebra system Maple and NLPSolve with the Modified Newton Iterative Method. It was found that the SAR-ADTM saturates, and the sum of the contents of saturates and ARO-1 can be predicted from vacuum residue density, while the SAR-ADTM asphaltene fraction content, and the sum of asphaltenes, and resins contents correlate with the softening point of the straight run vacuum residues. The softening point of hydrocracked vacuum residues was found to strongly negatively correlates with SAR-ADTM Aro-1 fraction, and strongly positively correlates with SAR-ADTM Aro-3 fraction. While in the straight run vacuum residues, the softening point is controlled by the content of SAR-ADTM asphaltene fraction in the H-Oil hydrocracked vacuum residues, the softening point is controlled by the content of SAR-ADTM Aro-3 fraction content. During high severity H-Oil operation, resulting in higher conversion, hydrocracked vacuum residue with higher SAR-ADTM Aro-3 fraction content is obtained, which makes it harder and more brittle. [ABSTRACT FROM AUTHOR]

Porous asphalt mixture (PA), known as open-graded surfaces over a stone bed underneath, allows water to go through. These factors can affect the porous asphalt mixture adhesive strength. The high amount of course aggregate promotes the structure of air voids have certain impacts on the acoustic properties of porous asphalt. The materials properties are consisting of both aggregate and bitumen tests. This study also details out the aggregates sieve analysis test to develop new aggregate gradation for PA. According to five ASEAN countries’ specifications, the sieve analysis test was done. The countries included are Malaysia, Vietnam, Thailand, Singapore, and Indonesia. The test for the binder includes the softening point, penetration, and ductility. This study also investigates the addition of kenaf fiber in the mixture as an additive. Mechanical performance test for PA using Marshall Stability test to identify the strength and the properties of the conventional PA with the addition of kenaf fiber compared to the new gradation of PA incorporating kenaf fiber. From the results, the addition of 0.3% kenaf modified PA improved the performance of PA in terms of Marshall Stability and volumetric properties.

This study was designed to investigate the Performance of melted Expanded Polystrene (EPS) wastes on the quality of bitumen used in asphaltic concrete. The EPS materials were ground and then melted (200-400 oC) to form a slurry. Specific gravity of the EPS and chemical composition were determined by AAS analyses. The melted EPS was used as a modifier in mix proportions of 0, 2.5, 5, 7.5 and 10% by weight of bitumen. The 5% unmodified bitumen content obtained from the Marshall mix design was used to prepare asphalt concrete samples with 0 to 10% contents of melted EPS. The products were tested for Marshall stability, specific gravity, penetration, softening point, ductility, loss on heating, viscosity, flash and fire points and the melting point tests using standard methods. The ground EPS was uniform and well-graded (4.750-0.010 mm) with a specific gravity of 0.012, having a styrene structure with methanol on the ring. The specimen prepared with the specified mix proportion of EPS produced results that ranged between 5598.71-16937.70 N for Marshal stability; 2.02-3.54 for specific gravity; 129-152 mm for penetration; 42.80-47.50 oC for softening point; 75.00-32.90 cm for ductility; 0-3.48% for loss on heating; 208-2204 sec.STV for viscosity; 243.3-269.0 oC for flash point; 196.1-211.0 oC for melting point. The results also showed that with correlation coefficients ranging from r = 0.658-0.999, there is a strong positive correlation between the improvement exhibited in the specimen tested properties and melted EPS used in bitumen. At the 5% bitumen with 5% EPS by weight of asphalt concrete, the results of stability, flow and optimum bitumen content satisfied the British Standard Specification framework for polymer-modified bitumen and it is therefore suitable for flexible pavement construction. [ABSTRACT FROM AUTHOR]

Currently, huge amount of waste materials are being generating from different industries on the world. Among these plastic waste bottle is the most dangerous materials to the environment which needs solution. Ethiopia is on the verge of quick industrial development in different areas, along with high population growth. This development is an evident increase in the consumption of plastic bottle water. A disposal of huge consumed plastic bottles cause an environmental hazard and are considered non-biodegradable materials. The solution to this problem is reprocessing these non-biodegradable materials to save natural resources and minimizing environmental effects. This paper assessed the technique on how plastic waste materials can be reused in road construction. In this study, the plastic waste was used as an additive in the mix with 2%, 4%, 6%, 8% and 10% by weight of optimum bitumen content. The addition of plastic waste improved the workability of bitumen by reducing the ductility and improving the penetration and softening point. Also, the addition of plastic content (pc) to the mix improved the Marshall Stability, stripping resistance and rutting resistance. Conversely, plastic waste has an impact on the fatigue resistance of the mixture if it is added excessively. Finally, the addition of plastic waste could be applicable in stripping resistance if it is added up to 5% to the neat bitumen. [ABSTRACT FROM AUTHOR]

The waste generation from old rubber tires has been increasing and causing environmental degradation with the escalation of vehicles number especially in the cities. Bitumen is extensively used in flexible pavement construction and as its manufacturing industries were still growing, the cost has not been much affordable. This study aimed at evaluating the possibility of a partial replacement of ordinary bitumen by tire rubber waste, with the purpose to reduce not only the amount of rubber wastes dispersed in the nature, but also the material cost, while keeping or improving the bitumen product performance. The study used rubber waste powder as partial replacement to ordinary bitumen by 5%, 10%, 15%, and 20% of its weight and, with adequate samples, properties of the bitumen product were investigated, after checking the standard quality of used bitumen 60/70 grade. It was established that more adequate results were achieved at 5% of replacement, which showed the penetration value of 61.66 tenths mm, the softening point value of 52.750C, and the viscosity of 134 sec. Regarding the cost estimation of this new bitumen, a cost reduction of around 5.3% was realized. Therefore, the use of rubber waste powder would contribute not only to the reduction of the quantity of respective waste in the environment, but also influence on the material affordability. The use of other grades of bitumen than 60/70, as well as the strength and durability performance may be a good scope for further studies.

Coir fibers (CFs) and micronized rubber powder (MRP) can be derived from low or negative-value agricultural/industrial waste streams and provide economical and sustainable pathways to develop high-value engineered products. This study investigated the influence of adding these modifiers on the performance characteristics of asphalt binders. Samples were produced using a mixture of slow-setting anionic asphalt emulsion with various quantities of MRP (at 0, 2 and 10 wt. %) and two levels of short CFs (~ 1 mm and 2 mm) with different fiber contents (at 0, 2 and 5 wt. %). The performance of modified asphalt samples was assessed by penetration depth (PD), softening point (SP), and penetration index (PI). Full factorial statistical design was structured to reveal the influence of main effects of the wt. % MRP, wt. % CFs, and CFs length and their interactions on the performance of the modified asphalt. Based on the statistical experimental design, linear regression analysis was performed. The linear regression showed that adding CFs and/or MRP consistently reduced PD, increased SP values and improved PI values. The length of CFs significantly affected the performance, which becomes more distinct with the increased weight content of CFs at 5 wt. %. It was also discovered that the combined addition of short CF and MRP achieved similar PI values at the same weight content of MRP alone. [ABSTRACT FROM AUTHOR]

The quality of bituminous binders is commonly evaluated by the empirical tests. The functional approach to the evaluation of bitumen properties is a trend that has been applied in the last years. The dynamic shear rheometer (DSR) test has been widely used to determine the shear complex modulus of bitumen in the wide range of frequencies and temperatures. A lot of research works were focused on the effect of the chemical compounds of bitumen on the values of the shear complex modulus. The missing information related to the effect of the compound of bitumen on the elastic and plastic part of the shear complex modulus was input for the presented investigation. The significant effect on the elastic part of the complex modulus was determined only at the high temperatures (60 and 80 °C). The aromatics, resins and asphaltenes were identified as the influencing compounds. The important effect was also noted for the resins at the temperatures of 5 and 15 °C. It was also concluded that the effect of the saturates on the elastic part of the shear complex modulus is marginal. The effect of the aromatics and asphaltenes on the plastic part of the shear complex modulus was identified only at the temperature of 80 °C. The effect of these two compounds at other temperatures seems to be unimportant. The significant effect of the resins was stated for the temperatures of 15 °C and 5 °C. Their effect at other temperatures can be supposed as marginal. The negligible effect of the saturates on the plastic part of the shear complex modulus was deducted.

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to investigate the effect of hydrophobic polymer softening points on salt-based fillers used in antifreeze asphalt concretes (AFACs), moisture absorption, salt-release property and thermal stability were studied and the performance of antifreeze and moisture susceptibility of AFACs were also assessed. Without preheating procedure, the softening point did not show a positive effect on the conductivity of modified salts, but changed the salt-releasing property after being mixed with the asphalt concrete. Further testing through simultaneous thermal analysis and scanning electron microscope has shown that the experience of high temperatures (between 100 and 200 °C) softens the small hydrophobic particles into thin layers coated on the surface of the salt, while hydrophobers decompose at temperatures above 200 °C. The result of heating cycles indicates that, based on the SEM observation, there are four situations of hydrophobic polymer particles on the salt surface. The salt-releasing property trends could be divided into three typical patterns. Generally, a higher softening point of hydrophober produces a better moisture susceptibility of the AFACs, while the pre-heating treatment on salts reduced the moisture susceptibility of AFACs.

This paper summarises the experience gained in LUKOIL Neftohim Burgas refinery with the production of road asphalt from blends containing straight run and hydrocracked vacuum residues. The effect of diluting of the bitumen blends with fluid catalytic cracking gas oils and H-Oil heavy vacuum gas oil (HVGO) and straight run vacuum gas oil (SRVGO) is discussed. The influence of sulphur treatment of the bitumen blends on oxidative ageing and H2S release is argued. The impact of bitumen softening point on the oxidation rate was found to be described by a power function. [ABSTRACT FROM AUTHOR]

Samples of petroleum pitches were obtained from heavy pyrolysis resin and decant oil (heavy gas oil of catalytic cracking) by thermal polycondensation at atmospheric pressure, at temperatures of 380-400 and 410-440°С (for the resin and decant oil respectively), and with isothermal holding times of 30–480 min. Analysis of the dependence of the softening point on the mesophase content for the obtained samples showed that at the same mesophase content the pitches from decant oil exhibit a lower softening point compared with the pyrolysis resin pitches, for which the softening point approaches 300°C even with 30 % of mesophase. This suggests that it is impossible to obtain pitches from pyrolysis resin with a high mesophase content without preliminary preparation. On the other hand, it was shown that for pitches from decant oil it is possible to isolate up to 65% or more of the mesophase with a softening point not higher than 250°C. [ABSTRACT FROM AUTHOR]

Design of an appropriate sealant is crucial for reliable sealing and stable long-term operation of solid oxide fuel cells. We have investigated sealants based on barium aluminosilicate glass-ceramic modified with CaO and MgO. Focus of the research was on the 0.33BaO-0.20XO-0.33SiO 2 –0.05Al 2 O 3 –0.09B 2 O 3 system, where XO is CaO, MgO, or a mixture of the two. Key properties of the system were studied, and its applicability of different compositions to sealing of high-temperature solid oxide fuel cells was investigated. Thermal properties, such as softening point and a half-ball point of the glass, coefficients of thermal expansion and adhesion to Crofer 22APU steel were of primary concern. CaO-containing sealants of this system showed much lower softening point compared to that of MgO-containing sealants. The substitution of CaO with MgO had no detectable effect on the coefficients of thermal expansion of the sealants. The coefficients of all the studied compositions were in 11.2–11.6∙10−6 1/K range. All the compositions have good adhesion to both Crofer 22 APU steel and ZrO 2 -based electrolyte. CaO-containing sealant was tested under operation conditions of a fuel cell stack for ten days; the seal remained hermetic for that period with no visible signs of degradation or oncoming failure of the seal. [ABSTRACT FROM AUTHOR]

Evolution of ebullated bed industrial hydrocracking atmospheric and vacuum tower bottoms from 2015 (start-up) until now is analysed in terms of applicability of residue for production of road pavement bitumen. Increased conversion in this money-maker (cheap vacuum residue feed and marginal naphtha and gasoil products) unit is in line with the driving force for increased refinery profitability. Another advantage of higher conversion is the lower content of residue, which is the main source for hardly trade off fuel oil. Together with positive effects, conversion reveals some disadvantages in terms of VTB properties. Residue becomes harder and it was found that penetration depends from softening point through the whole conversion range of 65-93%, obtained at industrial H-Oil unit, in the following exponential dependence: Penetration at 25oC = 6964.6e-0.093×Softening point. Deterioration of Fraass breaking point of VTB (Vacuum tower bottom from hydrocracking of vacuum residue unit) is directly related to the higher VTB density at increased conversion. [ABSTRACT FROM AUTHOR]

The paper presents the results of a study of the effect of the concentration of bentonite nanoparticles on the thermomechanical characteristics of composites based on HDPE. The principal possibility of increasing the heat resistance of composites by sizing bentonite and functionalizing HDPE with methacrylic acid is shown. New approaches to the interpretation of the properties of polymer nanocomposites depending on the processes that occur at the interface of the formed mineral-polymer hybrid structures are presented. [ABSTRACT FROM AUTHOR]

In most European countries, Hot Mix Asphalt (HMA) technology is still being used as the standard for the production and processing of bituminous mixtures. However, from the perspective of environmental acceptability, global warming and greenhouse gas production, Slovakia is making an effort to put into practice modern technology, which is characterized by lower energy consumption and reducing negative impacts on the environment. Warm mix asphalt technologies (WMA), which have been verified at the Department of Transportation Engineering laboratory, Faculty of Civil Engineering, Slovak University of Technology (FCE, SUT) can provide the required mixture properties and can be used not only for the construction of new roads, but also for their renovation and reconstruction. The paper was created in cooperation with the Technical University of Ostrava, Czech Republic, which also deals with the addition of additives to asphalt mixtures and binders. It describes a comparison of the impact of some organic and chemical additives on the properties of commonly used bitumen binders in accordance with valid standards and technical regulations.

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The restrictive factor for maximisation of Unconverted vacuum tower bottom (UVTB) from ebullated bed hydrocracking process - H-Oil technology in bitumen production is its low resistance to hardening, determined by using a Rolling thin film oven (RTFO). The limitation in LUKOIL Neftohim Burgas (LNB) industrial production is up to 37% UVTB in blends with air blown straight run vacuum residue (SRVR). The intention to increase UVTB content in bitumen blend passes through a dedicated evaluation of available approaches for their effectiveness and contribution for redirecting hydrocracking residue from low cost, hard to produce, high sulphur fuel oil to more valuable bitumen production. Several chemical components are tested and neither Heavy vacuum gas oil (HVGO) from hydrocracking of vacuum residue, nor slurry oil from Fluid catalytic cracking (FCC), nor asphaltene fraction from solvent deasphalting, nor antioxidant can inhibit softening point (SP) measured by the ring and ball (R&B) method increase due to resistance to hardening at 163°C test. A slightly positive result is assigned to SRVR addition but even that it can not lower the SP increase of UVTB to bellow specification required value of 9°C. Two substances reveal significant reduction in UVTB SP increase: 8% atactic polypropylene (aPP) is capable to obtain 5.4°C and elemental sulphur - 6°C with only 0.23% additionally bonded sulphur. [ABSTRACT FROM AUTHOR]

The aim of this research is to study the physical, thermal, and rheological properties of bitumen modified with ethylene propylene diene monomer (EPDM) elastomer and hybrid nanoparticles including carbon nanotubes (CNTs) masterbatch and bentonite nanoclay. Modified bitumen samples were prepared by mixing 60/70 bitumen with 3% EPDM, 0.1% CNT masterbatch, and 1.5% and 4.5% bentonite nanoclay. It was found that addition of these nanoparticles increased the softening point, reduced the penetration degree as well as temperature susceptibility of the modified bitumens. Results of rheological studies in the linear viscoelastic range showed that for the hybrid samples reinforced with EPDM, CNT masterbatch, and nanoclay, complex shear modulus was increased at high temperatures and the rutting factor was shifted from 81°C for the unmodified bitumen to >90°C for the EPDM-nano-modified bitumens. Thermogravimetric analysis also showed the improvement in the thermal degradation behavior of the hybrid samples. Our results indicate that the addition of small amounts of the additives used in this work can highly enhance the viscoelastic behavior of the bitumen at elevated temperatures. According to the findings of this work, the addition of EPDM (3%) and hybrid nanoparticles of CNT masterbatch (0.1%) and bentonite nanoclay (1.5%) to bitumen can synergistically result in the lowest penetration degree, highest softening point, and lowest temperature susceptibility and has the potential to have a better performance in warm areas. [ABSTRACT FROM AUTHOR]

The quality of bituminous binders used in the construction and maintenance of road surfaces is currently assessed by empirical testing based on obtaining one value for specific boundary conditions, which were designed about 100 years ago. Basic empirical tests include the softening point and penetration, but the practice shows that these tests appear to be inadequate. The evaluation of changes of bitumen properties during the production and paving process of bituminous mixture is also important. The paper points out how the “traditional” tests as softening point and penetration and viscosity are sufficient to evaluate properties of bitumen binders.