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.     

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.     

The performance of hot mix asphalt in dynamic and static creep tests

The main objective of this research is to identify the parameters that can be measured by simple equipment. In this research study, the results of static creep test by using soil consolidation test equipment and dynamic creep test are compared. In this research study, the samples of hot mix asphalt were fabricated with two types of bitumen, three bitumen contents and two types of gradations. All tests carried out at three different temperatures. The results show that there is a positive correlation between the static initial strain and dynamic cumulative strain.     

The characteristics of hot mixed asphalt modified by nanosilica

The objective of this research is to investigate the characteristics of the hot mixed asphalt modified by 2%, 4%, 6%, and 8% nanosilica by weight of binder. Marshall stability, dynamic creep, and indirect tensile tests were used to study effects of nanosilica on performance characteristics of the mixtures. Results showed that nanosilica can improve Marshall stability, resilient modulus, indirect tensile strength, and fatigue life compared to unmodified mixtures. However, the tensile strength ratio parameter in the moisture sensitivity tests indicated a decrease in the resistance of the modified mixtures against moisture damage.     

沥青混合料改性用直接投放式聚合物的研究及应用

沥青混合料改性用直接投放式聚合物改性工艺，是一类新型聚合物改性沥青方式，具有添加使用方便、无需预先剪切和储存稳定等优点。综述了目前沥青混合料改性用直接投放式聚合物的应用进展。从改性剂类型，添加工艺和改性效果等方面进行了对比与探讨，指出了其发展方向。     

不同SBS含量的改性沥青对薄层磨耗层混合料路用性能影响

分析了不同SBS掺量(4.0%,4.5%,5.0%,5.5%)改性沥青对密实断级配薄层磨耗层混合料浙漏特性、飞散特性、高温稳定性及水稳定性等路用性能的影响.试验表明,随着SBS含量的增加,改性沥青的技术指标有明显提高,混合料的各项性能随之提高,当SBS含量大于5.0%时,改善效果最为显著,但是由于SBS含量增加,改性沥青存储稳定性有所下降。对剪切加工水平的依赖性增强,考虑到薄层磨耗层混合料的高技术要求,推荐SBS的掺量最好在5.0%以上,考虑原料造价和剪切加工水平,SBS的加入量最好控制在5.0%～6.0%。     

The effect of nanoclay as bitumen modifier on rutting performance of asphalt mixtures containing high content of rejuvenated reclaimed asphalt pavement

Using some kinds of rejuvenators to restore the characteristics of aged binder in reclaimed asphalt pavement might lead to reduction in rutting resistance. In this research, nanocaly was used as virgin bitumen modifier to compensate for the negative effect of rejuvenator in asphalt mixtures containing high percentages of reclaimed asphalt pavement. For this purpose, dynamic creep test was conducted on the mixtures containing 2%, 4% and 6% modified NC and 25%, 50%, 75% RAP. Laboratory test results indicated that the reduction of flow number due to adding rejuvenator in the mixture can be compensated by using nanoclay modified virgin bitumen.     

高强度沥青及其混合料性能的试验研究

对高强度沥青与SBS改性沥青、70号沥青的性能进行对比检测，着重进行50℃、60℃下的动态剪切试验，以车辙因子（G^＊／sinδ）评价三种沥青的抗永久变形能力。结合室内试验，对AC-20型混合料的高温稳定性、水稳性、低温抗裂性以及疲劳性能等路用性能进行对比研究。研究结果表明，高强度沥青在50℃、60℃的G^＊／sinδ远高于其他沥青粘结料，能够大幅提高混合料的高温性能，而且对其他路用性能也有一定改善。     

塔河AH-90及改性沥青的性能分析与研究

利用四组分分析方法,对塔河AH-90系列沥青的化学组成进行分析,研究了合理的四组分搭配对优质石油沥青生产的重要性和不同组分对沥青性能各个指标的影响及相互作用。控制沥青质的生成对防止沥青老化有重要意义。     

剂量和稳定剂对SBR／SBS改性沥青性能的影响

通过多种性能评价方法，考察了SBR剂量以及添加稳定剂对SBR／SBS改性沥青性能的影响。试验结果表明，SBR剂量超过4%导致沥青离析。加入稳定剂使聚合物产生交联，导致SBR／SBS改性沥青的延度降低、粘韧性和抗变形能力提高。     

The effect of bitumen types on the performance of high-modulus asphalt mixtures

The objective of this study was the evaluation of high-modulus asphalt mixtures (HMAM). Two types of hard-penetration bitumen (HPB) and conventional bitumen were used to fabricate Enrobés à Module Elevé Class 2 (EME2) and Grave Bitumen Class 5 (GB5)) and control mixtures, respectively. In this study, complex modulus, fatigue, dynamic creep and moisture sensitivity tests and also, Witczak and Zhou models were used to evaluate the performance of the prepared mixtures. Results showed that hard-penetration bitumen (HPB) improved the performance of asphalt mixtures compared to conventional bitumen.     

Laboratory evaluation of the effect of bentonite on performance of bitumen and hot mix asphalt mixtures

In this research study, bentonite additive was used to modify original binder (60–70 penetration grade). The experimental program included use of five percentages of bentonite (10%, 15%, 20%, 25%, and 30%) by weight of bitumen. Physical properties of modified and unmodified bitumen were evaluated through penetration grade, softening point, ductility, and temperature susceptibility tests. The performance characteristics of mixtures were determined through indirect tensile strength, resilient modulus, and moisture susceptibility tests. The results demonstrate that addition of bentonite improves Marshall stability, tensile strength, and resilient modulus of mixtures, but led to decrease the resistance to moisture damage.     

Laboratory evaluation of the effect of waste plastic bottle (PET) on rutting performance of hot mix asphalt mixtures

The authors aim to evaluate the effects of using waste polyethylene terephthalate (PET) as a modifier on properties of asphalt mixtures. The rutting performance of asphalt mixtures that include various percentages of PET (0%, 0.25%, 0.5%, 0.75%, 1%) and various PET sizes (10 × 2.5, 20 × 2.5, and 30 × 2.5 mm) were evaluated through dynamic creep test and Hamburg wheel tracking device. Results indicated that the rutting resistance of mixtures increases by addition of PET contents and decreases with increase in PET sizes.     

Effect of nano titanium dioxide on heavy oil recovery during polymer flooding

In recent years, polymer flood of heavy oil has been extensively studied in laboratories and successfully applied in several fields. Polymer flooding is the most successful chemical enhanced oil recovery method. However, still, the need for a large amount of polymer, leading to high operational costs, presents a big challenge in technologies. This challenge can be addressed by considering the newly emerging nanomaterials. In this work, the author focuses on roles of TiO₂ nanoparticles on polymer viscosity and improve recovery in heavy oil recovery. He present the results obtained from a coreflood experiment with polymer injection in heavy oil at 1320 mPa.sec viscosity. Nanopolymer exhibits an outstanding flow behavior and enhanced oil recovery performance in coreflood displacement tests compared to base polymers. The results indicate that polymer flooding with higher viscosity can significantly improve oil recovery. Flooding test showed about 4% increase in oil recovery for nanopolymer solution in comparison with polymer solution after one pore volume fluid injection.     

纳米SiO2改善纤维复合防砂体的制备及性能研究

为了提高纤维复合防砂体的力学性能,采用在树脂涂覆砂中加入纳米SiO_2的方法对纤维复合体进行改性,通过超声波分散溶液共混法将纳米SiO_2(树脂质量分数的3%)均匀分散到水溶性酚醛树脂中,制备出纳米SiO_2改性树脂涂覆砂体,并加入纤维制备出纤维复合体。研究了不同防砂体的性能。结果表明,纳米SiO_2可以提高酚醛树脂涂覆防砂体的力学性能,几乎不影响纤维复合防砂体的渗透率,能使纤维复合体的强度提高;纤维可使树脂涂覆防砂体的渗透率提高11.13%。     

涠洲11-4油藏聚合物驱聚合物性能评价及优选

针对涠洲11-4油藏温度和流体性质特征,通过收集国内外现有高性能抗盐和耐高温聚合物产品,对聚合物溶液的增粘性、稳定性、耐温性、抗盐性和抗剪切特性、阻力系数和残余阻力系数等进行了测试,并引入模糊综合评判方法,借以对不同品质聚合物溶液改善流度比或扩大波及体积能力做出全面和客观评价。实践证明,模糊综合评判是进行聚合物溶液优选的一种简洁和有效方法。通过对实验结果综合分析表明,在初选的几种聚合物中,“法国SNF”在综合评价中性能居优。     

硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。     

环境响应型聚合物对水泥石抗CO2腐蚀性能的影响

利用压汞法、扫描电子显微镜和X射线衍射仪等分析方法研究了环境响应型聚合物ERP对油井水泥石抗CO₂腐蚀性能的影响,并揭示了其改善水泥石抗腐蚀性能的作用机理。结果表明,聚合物ERP使腐蚀60 d的水泥石孔径分布发生明显变化,有害孔（>100 nm）减少51.13%,微细孔（<50 nm）增大32.07%,总孔隙率降低16.31%,孔径细化;聚合物ERP可在水泥石遇酸表面或者内部形成一层膜状物质,膜状物质有效屏蔽了腐蚀介质与水化产物的直接接触,保持了水泥石结构完整性和水化产物相对稳定性;ERP改善水泥石抗腐蚀性能的作用机理为形成水化产物"包被层",减少与离子交换源接触机会;腐蚀环境下形成连续分布"膜状物质",阻断酸性腐蚀介质渗流通道。     

Nanocatalysts: Effect of Active-phase and Promoter on Catalytic Properties and Performance in the Hydrodesulfurization Reaction

The influence of various amounts of phosphorus addition on performance of NiMoP/Al₂O₃ and CoMoP/Al₂O₃ nanocatalysts was examined in hydrodesulfurization of thiophene. The nanocatalysts were synthesized via sonochemical technique. The prepared samples were characterized by XRD, FESEM, BET, and FTIR analysis. The catalytic activity in hydrodesulfurization reaction was investigated in a batch stirred slurry reactor at 160°C and atmospheric pressure. The characterizations confirmed highly dispersion of active phase and formation of amorphous AlPO₄ species on the support surface. The results obtained from thiophene hydrodesulfurization showed the nanocatalysts contained 1 wt% of phosphorus had the highest activity. The CoMoP/Al₂O₃ and NiMoP/Al₂O₃ nanocatalysts with optimum phosphorus loading nearly gave 100% conversion of thiophene, so that the sulfur compound concentration in final solution was less than 50 ppm.