聚合物改性沥青的研究进展

介绍了目前聚合物改性沥青的研究进展,包括改性聚合物种类、聚合物改性机理及其性能评价方法,并阐述了聚合物改性沥青技术的发展趋势.     

纳米改性沥青材料研究进展

介绍了纳米改性沥青技术进展,分析评价了各种纳米材料对沥青及沥青混合料性能的影响,指出了目前纳米改性沥青技术存在的问题。为提高改性沥青的性能,应综合分析影响纳米改性沥青性能的因素,并对改性效果进行定量评价,为全面评价道路沥青的经济效益、环境效益等提供理论参考。     

聚合物改性水泥基材料研究进展

讨论了聚合物改性水泥基材料的历史、性能及改性机理。从力学性能及韧性、耐久性两方面说明了聚合物改性水泥基材料性能,从微观形貌、孔结构和聚合物与水泥基体的作用三方面详细讨论改性机理。最后,对聚合物改性水泥基材料的发展趋势进行了讨论。     

聚合物砂浆的研究进展

综合介绍了国内外聚合物砂浆的发展现状、分类与性质.与普通砂浆相比,聚合物砂浆具有许多优良的性能,因此研究和发展聚合物砂浆具有现实意义.探讨了聚合物砂浆的作用机理以及应用,介绍了聚合物砂浆在应用中存在的问题,并据此对聚合物砂浆的应用进行了展望.     

改性沥青的研究进展

为了得到性能更优良的改性沥青,越来越多的材料被用作改性沥青改性剂,同时新的评价标准和方法及其他领域的新化学分析方法也被用来更完整准确地评价改性沥青的性能。总结了国内外改性沥青的研究现状及进展,从改性机理、性能影响因素及评价方法等方面来介绍各种改性沥青的概况,并概述了改性沥青的发展方向。     

聚合物改性沥青工艺研究

以石油沥青作为原材料,在普通物理共混改性的基础上,添加交联剂和催化剂,对石油沥青进行改性,并对其改性工艺条件进行了研究。结果表明,交联剂、催化剂能促使聚合物与基质沥青产生化学连接,形成空间网络结构,提高沥青性能。与此同时,交联剂用量、改性温度、改性时间等也与改性沥青性能有关。当DVB/aspha lt=0.0125(质量比)、催化剂/aspha lt=0.025(质量比)、改性温度为140℃、改性时间为2.5 h时,改性沥青的软化点由49.5℃升高至63.5℃,针入度由68.5(0.1 mm)下降至39.1(0.1mm),改性沥青性能得到明显改善,其性能也趋于稳定。     

聚合物改性沥青高温抗变形特性实验研究

为研究短期老化作用、温度分别对3种聚合物改性沥青:SBS改性沥青(SMA)、橡胶粉改性沥青(RPMA)、复合改性沥青(CMA)抗变形能力的影响,利用动态剪切流变仪(DSR)分别对3种沥青原样及旋转薄膜烘箱老化(RTFOT)后的沥青试样进行重复蠕变恢复实验,利用抗变形指数HL与蠕变劲度的粘性部分GV对沥青高温变形性能进行评价;并利用扫描电子显微镜对各沥青试样的微观结构形态进行观察,从微观角度解释不同沥青抗变形能力存在差异的原因。结果表明,GV与HL可较好地评价高温下改性沥青的抗变形能力;短期老化作用使基质沥青与改性剂的微观结构发生变化,抗变形性能改变;温度对沥青抗变形能力的影响取决于沥青温度敏感性的强弱,RPMA在高温状态下表现最好。     

离子注入技术改性聚合物薄膜的研究进展

离子注入技术改性聚合物薄膜在电子及电器工程中有着巨大的潜在应用价值。综述了近年来聚合物薄膜经离子注入后在导电性能,光学性能,导磁性能及表面力学机械性能等方面的最新进展。分析了注入离子与聚合物相互作用的物理过程,并指出了该领域存在的问题及发展方向。     

Stress growth coefficient in polymer modified asphalt

Startup flow of asphalt modified by styrene-butadiene-styrene and ethylene-vinyl acetate copolymer is studied at temperature T=60°C. It is shown that the base asphalt and blends with a low content of polymer (2% by weight) behave as linear viscoelastic materials. With increasing concentrations of polymer, the behaviour of the studied blends is nonlinear and can be described by the generalized rubber-like constitutive equation with separable memory function. The startup flow test seems to be ideal for the characterization of polymer modified asphalts in large deformation.

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Résumé Les courants de départ des bitumineux modifiés par styrène-butadiène-styrène et ethylène-vinylacétate co-polymères sont étudiés à des températures T=60°C. Il est montré que le bitumineux de base et les mélanges de bas contenu de polymères (2% par poids) se comportent comme un matériel linéaire viscoélastique. Avec une concentration croissante de polymère, le comportement des mélanges étudiés est nonlinéaire et peut être décrit par l’équation généralisée de constitution de type caoutchouc avec une fonction de mémoire séparable. Les essais de courants de départ semblent idéaux pour la caractérisation des bitumineux modifiées par polymère de grande déformation.

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Editorial note Prof. Ludo Zanzotto is a RILEM Senior Member. He participates in RILEM TC 182-PEB ‘Performance testing and evaluation of bituminous materials’.     

Relations between thermal degradations of SBS copolymer and asphalt substrate in polymer modified asphalt

The variations in the chemical characteristics of asphalt constituents and styrene–butadiene–styrene triblock copolymer (SBS) in the polymer modified asphalt (MA) during degradation process should be clarified to design the effective recycle method of MA. In this study, the chemical characteristics of MA during thermal degradation process were studied in detail. The effects of the period of thermal degradation of MA, the content of asphaltene constituent in MA and the kind of substrate instead of the straight asphalt were discussed from the yield and thermogravimetry (TG) curves of four constituents in MA and the molecular weight distribution of SBS. As a result, the yield of polar constituent (asphaltene) increased gradually with decomposition of SBS during thermal degradation of MA. Decomposition of SBS was enhanced by the low molecular weight substrate, such as aromatic oil. On the other hand, decomposition of SBS was inhibited by MA of high asphaltene content.     

废胶粉改性沥青性能研究

采用间隙自调节沥青生产设备(自制),以不同废胶粉及其不同掺量对不同沥青的改性效果进行了试验研究,主要分析了废胶粉的掺量对沥青性能的影响;从改性沥青的各项性能指标得出,废胶粉掺量在15%~20%是合适的,并且随着胶粉掺量的增加,沥青的性能会发生一系列变化:软化点升高、低温延度增大、针入度下降。     

环氧沥青改性材料研究及发展建议

环氧沥青以优于普通沥青的物理和化学性能在诸多领域得到了广泛应用,为推动环氧沥青技术的开发应用,综述了国内外环氧沥青的研究进展.首先,介绍了热固性环氧沥青自身缺陷及面临的技术问题;然后,探讨了环氧沥青的组分、分子结构和工作机理,分析了冷拌、温拌和热拌环氧沥青的使用特点,进而从增韧、相容性和固化剂3个方面讨论了环氧沥青的主...     

Energy saving and environmental friendly wax concept for polymer modified mastic asphalt

This paper focuses on the addition of commercial wax as flow improver in polymer modified bitumen intended for use in mastic asphalt pavements under Nordic climatic conditions. Different aspects are dealt with. The aim of the project is to make mastic asphalt used in Sweden today (for bridges, parking decks etc.) more environment friendly and easier to handle. However, wax modification must not have any noticeable negative impact on the performance of mastic asphalt at medium and lower temperatures. The project involves laboratory testing of wax and polymer modified binder mixtures as well as mastic asphalt mixtures. Effects of adding two commercial waxes to one polymer modified bitumen have been studied. The results show that both waxes have a flow improving/viscosity depressant impact on the polymer modified bitumen at higher temperatures, indicating a possible lower laying temperature for the mastic asphalt if modified with such waxes. Moreover, there is a stiffening effect at medium and high temperatures (below placing temperature), indicating a certain positive effect on stability. Concerning low temperature performance, there are results indicating some negative impact on crack susceptibility at low temperatures, more by the addition of one of the waxes than by addition of the other. However, it could be concluded that using up to at least 4% of either wax additive will improve workability for the mastic asphalt product under investigation making it possible to lower working temperatures without seriously affecting its good performance in any negative way.     

基于数字散斑相关法的聚合物改性沥青混合料抗裂性能

为分析冻融循环对苯乙烯-丁二烯-苯乙烯（SBS）和橡胶粉（CR）改性沥青混合料抗裂性能的影响,首先,分别对盐溶液冻融循环和水溶液冻融循环改性沥青混合料进行了半圆试件弯拉试验,同时采用数字散斑相关法（DSCT）对加载过程试件表面的散斑图像进行处理,提取试件表面随着载荷变化的位移场和应变场信息;然后,通过分析变形场信息确定沥青混合料的抗裂性能,并与断裂韧性试验结果进行对比。结果表明:水平应变较适合用于对沥青混合料的抗裂性能开展特性研究;由水平应变-时间曲线可知,冻融循环后SBS和CR改性沥青混合料的抗裂性能均有所劣化,且盐溶液冻融循环对沥青混合料抗裂性能的影响要大于水溶液冻融循环的;与SBS改性沥青混合料相比,CR改性沥青混合料的抗裂性能较好。所得结论表明DSCT的分析结果与断裂韧性试验的分析结果一致,采用DSCT评价沥青混合料的抗裂性能是可行的。      

纳米氧化铝在聚合物改性中的研究进展

聚合物经纳米氧化铝填充改性后,其力学性能、表面性能、电学性能及热性能等普遍能够得到改善。综述了近年来对纳米氧化铝改性聚合物的研究进展,重点讨论了纳米氧化铝在聚烯烃、聚酯、聚酰胺、其它塑料树脂及橡胶改性中的应用,并对纳米氧化铝改性聚合物的发展趋势及应用前景作了展望。     

Modified toughness used to evaluate the effect of polymer modified asphalt on SMA

Abstract

Toughness, as defined in ASTM D5801, is the work used to stretch a specimen until fracture, and is used to evaluate the ability of polymer modified asphalt (PMA) to resist deformation. Fracture elongations in PMA are usually longer than 10 cm. However, it is almost impossible for asphalt concrete, with or without PMA, to endure such large deformation before fracture. It is presumed that an effective elongation exists for more effective determination of toughness. Principle component analysis (PCA) and single regression analysis were used in this study to evaluate the correlation between physical tests of PMA, including toughness and performance tests of Stonic Mastic Asphalt (SMA). Meanwhile, performance tests, including resilient modulus tests, creep tests and indirect tensile tests, were conducted on SMA samples. According to the results form Principle Components Analysis (PCA), it was observed that only a common factor affects the performance tests. Regression analyses were used to find common factors from physical tests of PMA. Correlation coefficients between toughness and performance tests were found to be better than other physical tests. When toughness was calculated with effective elongation (6.5 cm), R ² was 0.90. In our opinion, the desirable PMA should provide SMA enough work to resist the deformation while the deformation is still small. This result was also confirmed by observation of SEM and Rheological analysis. Modified toughness (calculated with effective elongation) considered as the common factor, is a simple method to evaluate the microstructure of PMA. Overall, modified toughness seems promising for use in evaluation of the effect of PMA on SMA.