High-temperature functional analysis of bitumen modified with composite of nano-SiO2 and styrene butadiene styrene polymer

In recent decades, researchers have always considered the production of modified bitumen that could perform suitably in both high and low temperatures. One bitumen modifier is styrene butadiene styrene (SBS) polymer. Because bitumen modified with styrene butadiene styrene polymer does not show expected field performance in high and low temperatures largely due to phase separation of bitumen and polymer, the present research study is an attempt to use the composite of nano-SiO₂ and styrene butadiene styrene polymer in modification of bitumen and analyze its high-temperature performance. The study revealed that adding nano-SiO₂ to bitumen modified with SBS polymer resulted to an improvement of complex modulus, phase angle, resistance potential against rutting, storage modulus, loss modulus, and high-temperature functional performance in general. Additionally, the study uncovered that adding nano-SiO₂ with 3% and 4% of bitumen weight, compared with other composites, considerably improved the high-temperature functional performance of bitumen modified with styrene butadiene styrene polymer. As 4.5%SBS+4%nano-SiO₂ could not estimate less than 3 Pa.sec rotational viscosity in 135°C, 4.5%SBS+3%nano-SiO₂ is offered as the optimal composite. The study is the first one in its own type in the world and is, therefore, innovative.     

Low temperature functional analysis of bitumen modified with composite of nano-SiO2 and styrene butadiene styrene polymer

Most parts of Iran have completely different climates in different seasons of year. In other words, in summer it is very warm and in winter it becomes very cold. Achieving modified bitumen that could function adequately in both high and low temperature has always been under attention of researchers. One of bitumen modifiers is styrene butadiene styrene polymer. Because bitumen modified by styrene butadiene styrene does not show expected field function in both high and low temperatures, largely due to phase separation of bitumen and polymer, in the present study it has been tried to analyze the low-temperature function of bitumen modified by combining nano-SiO₂ and styrene butadiene styrene polymer. The study reveals that adding nano-SiO₂ by 3% and 4% of bitumen weight to the double combination of bitumen and styrene butadiene styrene polymer has improved its function in low temperature. This study has innovation as it deals with the analysis of low temperature function of nano-SiO₂ and SBS in modification of bitumen for the first time in the world.     

The rheological properties of a bitumen emulsion modified with two types of SBR latex

Bitumen emulsions have recently been taken as one of the most frequently used binders for asphalt surface treatments (AST). Making use of modified bitumen emulsion is necessary to improve AST. Styrene butadiene rubber (SBR) is one of the most commonly used modifiers. The present research study tested the residue of normal and modified bitumen emulsion with different percentages of SBR and X-SBR using ordinary and dynamic shear rheometer methods. The findings revealed that increasing latex SBR led to increasing softening point and needle penetration, so that temperature sensitivity of bitumen residue is reduced. The stiffness of modified bitumen emulsion residue improved significantly by increasing the percentage of SBR. Furthermore, comparing the effect of SBR and X-SBR on bitumen emulsion uncovered that in equal polymer percentage of 6%, X-SBR promoted performance graded for at least one performance grade. Finally, the study is innovative as it dealt with the comparison of high-temperature performance analysis of the impact of polymer percentage simultaneous with that of SBR structure on improving bitumen emulsion.     

High-temperature performance and microstructure of composite modified hard asphalt

Composite modified hard asphalt (CMHA) was prepared by four-step high-speed shearing method adding crumb rubber, styrene-butadiene-styrene (SBS) copolymer, and hard asphalt to QHD AH-70 neat asphalt. The high-temperature performance and microstructure of CMHA were evaluated by rotational viscometer, fluorescence microscopy, and infrared spectroscopy, through which the modification mechanism was proposed. The results show that the shearing time had great influence on the high-temperature performance of CMHA. A significant variation in phase morphology of CMHA during preparation was observed. It is found that phase morphology was converted from a continuous asphalt phase with dispersed polymer phase to two twisted continuous phases, then to a continuous asphalt phase with dispersed polymer phase again. Preparation of CMHA was a complex physical and chemical process. A fraction of SBS took part in the chemical reaction and others were dispersed in net structure, which is beneficial for workability and performance of asphalt.     

广州新白云机场南北主进场路沥青路面的铺筑

介绍了南海牌AH-70重交通道路沥青及SBSI-C改性沥青的技术性能及其用于广州新白云国际机场的机场主进场路面铺筑情况,详细阐述了机场主进场路面的组成结构、沥 青混合料的组成材料及技术性能指标.马歇尔试验得到,沥青混合料的稳定度在12～14 kN,流值在25～27 1/10 mm;车辙试验中,改性沥青混合料为3 500次/mm,AH-70重交通道路沥青混合料为1 700次/mm.施工实际抽检结果,混合料马歇尔试验稳定度在11.58～14.80kN,流值为24.3～30.4 1/10 mm,平整度、纹理度等各项指标均达到或超过JTJ 032-1994“公路沥青路面施工技术规范“要求.     

Preparation of an SBS Latex–Modified Bitumen Emulsion and Performance Assessment

Abstract

For resolving the contradiction of the stability between styrene-butadiene-styrene (SBS)-modified bitumen emulsion and the concentration of SBS, a method of preparing SBS latex is provided in this article. Results showed that SBS latex had good stability properties and performance. The effect of emulsifier concentration on the storage stability showed that the maximum stability of SBS latex–modified bitumen emulsion (SBS-LMBE) was obtained at emulsifier weight concentration 1.0% and addition of SBS latex to bitumen emulsion enhanced the difficulty of emulsification. The effects of SBS latex on bitumen properties showed the penetration decreased, whereas the softening point and ductility at 5°C increased, which means that SBS latex plays a role in improving the properties of bitumen. Compared to the base bitumen, saturate and aromatic of evaporation residue of SBS-LMBE decreased. However, resin and asphaltene increased. Analysis of the relationship between the components and properties of bitumen showed that the components change caused by SBS latex was beneficial to the properties of bitumen. The colloidal index (CI) showed that SBS latex also made the colloidal system more stable.     

The rheological behavior of bitumen and moisture susceptibility modified with SBS and nanoclay

The effect of styrene–butadiene–styrene (SBS) and nanoclay additive on performance of pure bitumen and stone matrix asphalt (SMA) mixture was investigated. Different samples with various percentages of nanoclay (2%, 3%, 4%, and 5%) and SBS (0% and 5%) by weight of bitumen were prepared, and the rheological and chemical behavior of bitumen (rotational viscosity, dynamic shear rheometer, SEM, and FTIR), the indirect tensile strength and moisture susceptibility of different mixtures were evaluated. Based on the results, using nanoclay and SBS polymer can improve the rheological behavior of base binder and the resistance of SMA mixtures against moisture damage.     

高模量沥青混合料路用性能试验研究与评价

为了研究高模量沥青混合料的综合路用性能,通过对AC-25C（30号）、AC-20C（30号）、AC-20C（70号SBS）、AC-25C（70号）沥青混合料的高温性能、低温性能、疲劳寿命和水稳定性等试验研究。对比试验和分析了不同沥青混合料的路用性能,从而比较出高模量沥青混合料的优越性。     

Rutting resistance and resilient modulus evaluation of polymer-modified SMA mixtures

Ethylene copolymer bitumen (ECB), namely Lucobit, as a thermoplastic polymer, SBS as a thermoplastic-elastomer polymer, and ethylene-vinyl-acetate (EVA) combined with Fischer-Tropsch wax and resin additives, namely Rheofalt WKR-2, as a modified thermoplastic polymer were used for stone matrix asphalt modification. Two types of asphalt modification processes including polymer-modified bitumen (PMB) and direct addition of polymer into mixture were employed and the effect of each one on resilient modulus and rutting resistance was evaluated by performing Indirect Tensile Resilient Modulus and Hamburg Wheel Tracking tests. PMB, SBS, and Rheofalt-modified mixtures resulted in lower rut depth and higher resilient modulus than did those modified by ECB. In direct addition of the polymer into mixture process, there is reduction in rutting resistance and resilient modulus of Rheofalt-modified mixtures in comparison with PMB. Furthermore, there was no improvement for ECB-modified mixtures by direct addition modification.     

Ammonium perchlorate-based molecular perovskite energetic materials: preparation,characterization, and thermal catalysis performance with MoS2

ABSTRACT

In this study, ammonium perchlorate (AP)-based molecular perovskite structural high-energetic materials (H₂dabco)[NH₄(ClO₄)₃] (DAP) were fabricated and their catalytic performance upon the addition of MoS₂ nanosheets was investigated. The DAP samples were succesfully prepared via a self-assembly reaction and their morphology and structure were characterized via scanning electron microscopy, X-ray diffractometry, and Fourier transform infrared spectroscopy. The thermal decomposition performance of a pure DAP sample and of a mixture of DAP with MoS₂ nanosheets were analyzed via differential scanning calorimetry. The results show that DAP has a high thermal stability at its initial decomposition temperature of 319.8°C, and that its apparent decomposition heat measures 4199 J/g. This value is higher than for AP (829.7 J/g). Furthermore, the thermal decomposition peak temperature of DAP upon the addition of 1 wt% and 3 wt% MoS₂ nanosheets decreases from 394.4°C to 343.3°C and 328.8°C, respectively. The investigation of the catalysis thermal performance of DAP may foster its practical application in composite propellant.     

The effect of warm additive on the properties and behavior of an asphalt binder

Use of warm asphalt mix has been recently receiving a great attention because it allows decreasing production and distribution temperatures about 30–40°C by either reducing bitumen viscosity or enhancing mixture performance. These mixes also have other advantages such as a low pollution, reduced fuel consumption, and more implementation seasons. Despite these benefits, there is a constant concern about the performance of these mixes under the conditions such as permanent deformation, fatigue cracking, and low-temperature cracking. In the present study, two types of bitumen modifiers including liquid additive and Sasobit were used to adjust rheological properties of bitumen. After conducting the required tests on bitumen specimens prepared using these two additives and comparing the results obtained from two common and Strategic Highway Research Program tests under aged and nonaged conditions, it was revealed that, considering the viscosity of bitumen, these additives improve bitumen performance at ambient temperatures. Besides, the results indicate the improvement in rutting criteria (G^*/sinδ) and fatigue criterion (G^*×sinδ).     

The Effect of Nanoclay on Rheological Properties and Storage Stability of SBS-Modified Bitumen

Abstract

Linear and branched grades of styrene-butadiene-styrene (SBS) triblock copolymer are commonly used for modifying physical, mechanical, and rheological properties of bitumen. Because bitumen and SBS are incompatible, SBS-modified bitumen is not storage stable at elevated temperatures. Incompatibility of branched SBS is greater than linear SBS. To obtain greater compatibility between SBS and bitumen, organophilic montmorillonite/SBS-modified bitumen mixtures, prepared by melt intercalated blending, were used. Results showed that the presence of nanoclay could improve the storage stability, aging, and high-temperature performance of polymer-modified bitumen (PMB) significantly. Of course, this effect can be seen by proper dispersion of organophilic montmorillonite (OMMT) in SBS and obtaining a homogenous blend, which is calleed an exfoliated structure. The structure of OMMT/SBS/bitumen blend was characterized by X-ray diffraction (XRD).     

用辽河沥青生产SBS改性沥青的研究

对于聚合物改性沥青来讲，沥青与聚合物的相容性及改性沥青的储存稳定性对于沥青的储存，运输及使用都是非常重要的问题，本研究以辽河AH-90，辽河AH-140沥青为基质原料，通过选择合适的加工路线和工艺条件，制备出性能良好，PG分级较高，具有良好的热储存稳定性的SBS改性沥青。     

The Evaluation of Oil Sand Bitumen Produced From Inner Mongolia

On the basis of an analysis, the bitumen produced from Inner Mongolia oil sand belongs to a kind of sour naphthenic based oil with the properties of high density (ρ₂₀ = 0. 9996 g·cm^?3), high viscosity (υ₁₀₀ = 1553/(mm²·sec^?1)), rich resin, and asphalt. After a series of fractions is cut by true boiling distillation (TBP) SBD-β instrument and analyzed by corresponding instruments, the processing scheme of tar sand bitumen is proposed. The initial boiling point is 281°C, and the yield of diesel, lube oil, and residual oil is 4.54%, 16.73%, and 38.06%, respectively.     

Effect of C9 petroleum resins on improvement in compatibility and properties of SBS-modified asphalt

Various amounts of C9 petroleum resin (PR) were added to the starting materials for the preparation of low 4% and 8% SBS content polymer modified asphalt (PmA). Morphology, physical properties and rheological performance of each SBS-PmA are investigated by using fluorescence microscope (FM), routine tests and dynamic shearing rheometer (DSR). Routine tests and DSR results reveal that high-temperature performance of PmAs are markedly improved by using a proper content of C9 PR, especially for SBS-PmA with 8% SBS content. FM results show that incorporation of C9 PR is beneficial to the dispersion behavior of SBS in asphalt binder.     

国产SBS改性沥青在高速公路上的应用

采用改性沥青及其沥青玛蹄脂碎石混合料路面，可以全面提高沥青路面的高低温性能。介绍了改性沥青工艺技术，重点阐述了在浙江省(ZJS)高速公路嘉兴段用于中面层(AC—161)和表面层(SMA—13)混合料的改性沥青类型、SBS改性剂、基质沥青的选用、工艺配比设计、改性沥青的现场加工工艺及其质量控制，并与品牌成品改性沥青的性能进行了比较。结果表明．采用国产东海脾重交沥青作为基质沥青、LG501 SBS作为改性剂，胶体磨工艺设备大规模生产SBS改性沥青，具有优良的综合性能，满足ZJS高速公路中面层(AC—161)及罩面层(SMA—13)改性沥青路面设计、施工的质量要求。     

SBS改性沥青质量影响因素探讨

从基础沥青、苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）加入量、SBS化学结构、相对分子质量、嵌段比、凝胶含量、膨化度等方面分析了原料对改性沥青性能的影响。并指出提高SBS改性沥青性能的主要措施为SBS的加入量控制在4％～6％；并根据基础沥青的芳香分含量调整SBS的嵌段比等。     

三种原油混炼制备道路沥青及防水卷材技术研究

介绍了加拿大冷湖原油、伊拉克巴士拉原油和南美原油三种原油在高等级道路沥青和防水沥青生产中的应用。通过实验室研究,开发出了混炼三种原油生产道路沥青的工艺路线:冷湖原油、巴士拉原油与南美原油以4:3:3比例蒸馏可以生产出性能优良的AH-90号、AH-50号高等级道路沥青。以混炼AH-90号沥青为原料,采用复合聚合物改性方法制备弹性体(SBS)改性沥青涂盖料及防水卷材。对低温柔性、耐热性等指标进行检测,均满足NB/SH/T0981—2019《防水材料用沥青》和GB18242—2008《弹性体改性沥青防水卷材》标准技术要求。为道路沥青及防水产品生产提供了新思路。     

Optimal activated carbon for separation of CO2 from (H2 + CO2) gas mixture

Seven types of activated carbon were used to investigate the effect of their structure on separation of CO₂ from (H₂ + CO₂) gas mixture by the adsorption method at ambient temperature and higher pressures. The results showed that the limiting factors for separation of CO₂ from 53.6 mol% H₂ + 46.4 mol% CO₂ mixture and from 85.1 mol% H₂ + 14.9 mol% CO₂ mixture were different at 20 C and about 2 MPa. The best separation result could be achieved when the pore diameter of the activated carbon ranged from 0.77 to 1.20 nm, and the median particle size was about 2.07 lm for 53.6 mol% H₂ ? 46.4 mol% CO₂ mixture and 1.41 lm for 85.1 mol% H₂ + 14.9 mol% CO₂ mixture. The effect of specific area and pore diameter of activated carbon on separation CO₂ from 53.6 mol% H₂ ? 46.4 mol% CO₂ mixture was more significant than that from 85.1 mol% H₂ ? 14.9 mol% CO₂ mixture. CO₂ in the gas phase can be decreased from 46.4 mol% to 2.3 mol%–4.3 mol% with a two-stage separation process.     

塔河稠油沥青改性及应用研究

介绍了以塔河稠油沥青为原料的SBR改性、SBS改性沥青工艺，重点阐述了根据路面应用要求设计生产的改性沥青性能，选定AC-13级配进行混合料性能研究，表明塔河稠油SBR改性沥青和SBS改性沥青路用性能优良，满足高等级公路建设要求。