改性乳化沥青的研究进展及其应用

改性乳化沥青是一种新型道路建筑材料,兼具改性材料和乳化沥青的优点,在微表处、粘结层和雾封层材料等方面具有广阔的应用前景。论述了以改性剂类型为划分依据的两类改性乳化沥青的研究进展,对其进行归纳总结并分析了各自的优缺点,介绍了现阶段改性乳化沥青的应用现状。指出未来在寻找性能优良全面的改性乳化沥青过程中,应围绕新型改性剂研发来进行开展。     

改性乳化沥青磨耗层施工工艺浅析

通过对改性乳化沥青磨耗层的功能、材料要求以及施工工艺特点进行简要的分析,并进行了大量的施工应用,证明改性乳化沥青磨耗层具有较好的路用效果,综合性价比也较高。     

水性环氧树脂改性乳化沥青用作粘层

为了研究水性环氧树脂对乳化沥青的改性特征及其应用效能,对水性环氧树脂改性的乳化沥青的牢固性和黏度进行测试,并且对其进行马路使用测试。结合室内试验和数据分析表明:水性环氧树脂可有效提高乳化沥青的稳定性和黏度,确定了可用作粘层。     

路用水性环氧改性乳化沥青组成优化及耐久性能评价

为提升改性乳化沥青在道路领域的使用品质和耐久性,制备了多种水性环氧改性乳化沥青,基于拉伸性能优化了改性乳化沥青配比,研究了水性环氧改性乳化沥青的黏附性能、黏度、干燥时间、相容性和粘结性能,分析了水性环氧改性乳化沥青粘结性能与其拉伸性能、黏附性能的关联性,采用湿热老化、冻融循环和氙灯光照老化等方式模拟复杂气候条件对水性环氧改性乳化沥青的破坏作用,以经老化处理后的残留拉伸、黏附和粘结性能及处理前后各项性能的变化率作为评价指标,基于熵权的理想点法综合评价了水性环氧改性乳化沥青的耐久性能。结果表明：水性环氧树脂能够有效提升乳化沥青的拉伸强度和黏附性能,水性环氧改性乳化沥青具备较好的流动性和适宜的干燥时间,且水性环氧树脂与乳化沥青具有较好的相容性,建议水性环氧树脂掺量为15%～25%(质量分数,下同)。水性环氧改性乳化沥青的粘结性能与其力学强度和黏附性能具有较强的关联性。水性环氧改性乳化沥青经湿热老化、冻融循环或氙灯光照老化处理后拉伸、黏附和粘结等性能保持率为84%～92%,聚氨酯改性后的水性环氧改性乳化沥青表现出更好的耐久性能,聚氨酯改性双酚A型E-51水性环氧改性乳化沥青的综合耐久性能最佳。     

非离子丁苯胶乳改性乳化沥青性能研究

采用自主研发生产的非离子丁苯胶乳作为改性剂,对不同基质沥青进行改性,考察改性乳化沥青的各项性能.并在高速公路进行推广应用,取得较好效果,为非离子丁苯胶乳改性乳化沥青在路面上的应用提供借鉴.     

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。     

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。     

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。     

一种用于碎石封层的改性乳化沥青的性能

制备了Sasobit改性乳化沥青,碳链长度为C45-C100的Sasobit使改性乳化沥青残留物具有很好的高温性能:其软化点提高可到20℃,车辙因子增幅超过45%,60℃粘度可达3倍以上;与一般沥青中蜡的粗晶质结构相比,Sasobit的微晶结构则可减弱沥青路面低温下的脆裂性.Sasobit的链状结构和微晶结构保证了Sasobit改性乳化沥青路用性能优良,各项技术指标均明显优于普通的乳化沥青;用于碎石封层时可以明显提高路面强度及其抗变形能力.     

有机缓凝剂对水泥改性乳化沥青胶浆的改善效果研究

将适量的萘系减水剂(Naphthalene superplasticizer,NSP)加入到改性乳化沥青(Modified asphalt emulsified,MAE)中能够实现水泥和改性乳化沥青的直接拌和。当NSP的掺量为4%(质量分数,下同)时,水泥沥青胶浆(Cement asphalt mastic,CAM)工作性能不佳。本试验所使用的沥青和三种有机缓凝剂分别为:改性乳化沥青、海菜粉、聚丙烯酰胺(PAM)、葡萄糖酸钠。试验结果表明:海菜粉对CAM的改善效果最好。当海菜粉掺量为0.03%时,CAM 7 d内的强度增量比较大; 28 d的抗拉强度和抗压强度最高,凝结时间最短,干缩变化幅度较小。随着海菜粉掺量的增加,CAM的抗拉强度和抗压强度有所降低。PAM由于其自身有很强的粘稠度和絮凝作用,因而对CAM的粘弹性有很大影响;当PAM掺量为0.02%时,CAM的粘度最大,坍流度最小;当PAM掺量由0.01%增加到0.03%时,CAM的粘度、干缩量和抗压强度呈现先增大后减小的规律,坍流度和凝结时间呈现先减小后增大的规律,而抗拉强度随掺量的增加而增大。葡萄糖酸钠对CAM的改善效果最差,虽然加入葡萄糖酸钠能改善CAM的流动性、粘度等非力学性质,但会引起CAM试块较大幅度的体积收缩和干缩,抗拉强度和抗压强度明显降低,凝结时间过长,试件表面出现裂缝等不良现象。     

Determination of polymer content in modified bitumen

Polymer-modified bitumen (PMB) has been increasingly used to enhance pavement performance. Two styrenebutadiene-styrene (SBS) copolymers were mixed with two bitumens by weight of the blend. This paper aims at developing the procedure to determine the proper polymer content to be mixed with bitumen. Tests including storage stability test, dynamic shear rheometer and scanning electron microscopy (SEM) were conducted to investigate the viscoelastic properties and microstructures of PMB. The addition of polymers increased the viscosity, softening point, toughness and complex modulus of bitumens. SEM results indicated that, as the polymer content increased, SBS gradually became the dominant phase that resulted in an increase in PMB's mechanic properties. Good compatibility produced an elastic network into the PMB up to 6% polymer concentration. The optimum polymer content was determined based on the rheological properties and the formation of the critical network. Adding higher polymer contents could lead to the separation of polymer and bitumen. The softening point temperature difference between top and bottom samples should be controlled within 2°C to monitor PMB's stability.     

Dynamic mechanical behavior of polymer modified bitumen

The dynamic mechanical behaviour of bitumen (BIT) modified with styrene/butadiene/styrene block copolymer (SBS) were investigated. Dynamic mechanical analysis (DMA) were performed in the temperature range –80 to 60 °C. The primary viscoelastic functions were determined at the traffic frequency, 5 Hz. The BIT+SBS blends were investigated in creep fatigue regime at temperature 10, 20, 30, 40 and 50 °C. Dynamic mechanical behaviour of BIT+SBS blends depends on their morphological characteristics, number of phases, phase compositions and phase content in blend, as well as time and temperature. The curves of primary viscoelastic functions, storage modulus (E′), loss modulus (E′′) and loss tangent (tg δ) vs. temperature of polymer modified bitumen differ from unmodified bitumen and indicate the presence of the swollen polybutadiene and polystyrene phases in bitumen phase. The curve E′ vs. temperature of polymer modified bitumen show the rubbery plateau. With the increment of SBS content the rubbery plateau is shifted to high temperatures. At the constant load the creep values of BIT-SBS blends increase and those of creep modulus decrease over a period of time. These effect are more pronounced in samples with higer content of SBS. The time-temperature correspondence principle was applied to create master curves for the reference temperature 10 °C for the creep modulus of BIT + SBS blends. The data were analysed using WLF and Arrhenius equations. Electronic Publication     

French wheel tracking round robin test on a polymer modified bitumen mixture

In the framework of the RILEM TC 206-ATB TG3, a Round Robin Test (RRT) has been performed in order to evaluate the reproducibility of the French Wheel Tracking Test (FWTT) on a mix made with Polymer Modified Bitumen (PmB). For this mixture, some particular problems had been reported, such as excessive heating of the sample due to friction and sticking of the binder to the wheel. Two procedures, called anti-overheating and anti-sticking procedures, have been proposed by the group in order to improve the reproducibility of the wheel tracking tests. These procedures are assessed. Causes of scattering are discussed. Differences between the tyres used during this RRT as a possible origin of scattering are discussed, as well as temperature peaks and over-compaction of specimens.     

道路改性沥青的技术研发与展望

本文介绍了道路改性沥青技术的研发历史和现状,指出了研发以功能性改性剂的化学改性沥青技术,以及采用低价格、性能更好的改性剂和简单的生产设备及工艺以降低综合生产成本是今后沥青改性技术的发展趋势。     

Analysis of styrene-butadiene-styrene polymer modified bitumen using fluorescent microscopy and conventional test methods

This paper presents a laboratory study of modified bitumen containing styrene-butadiene-styrene (SBS) copolymer. Polymer modified bitumen (PMB) samples have been produced by mixing a 50/70 penetration grade unmodified (base) bitumen with SBS Kraton D1101 copolymer at five different polymer contents. The fundamental characteristics of the SBS PMB samples have been determined using conventional methods. The morphology of the samples as well as the percent area (%) distribution of SBS polymers throughout the base bitumen have been characterized and determined by means of fluorescence microscopy and Qwin Plus image analysis program, respectively. The mechanical properties of the hot-mix asphalt (HMA) containing SBS PMBs have also been analyzed and compared with HMA incorporating base bitumen. The effect of polymer addition on the short and long term aging characteristics of HMA have been evaluated by indirect tensile strength (ITS) test. The results indicated that polymer modification improved the conventional properties (penetration, softening point, etc.) and the mechanical properties (Marshall, ITS, etc.) of the base bitumen. It was also concluded that at low polymer contents, the samples revealed the existence of dispersed polymer particles in a continuous bitumen phase, whereas at high polymer contents a continuous polymer phase has been observed. Moreover, it was found out that the polymer addition minimizes the short and long term aging of HMA.     

功能性填料改性聚合物材料的摩擦学研究进展

聚合物材料因其质轻、价廉、耐腐蚀以及优异的自润滑特性而广泛应用于工程机械润滑领域中。加入功能性减摩和增强填料复合改性聚合物树脂可以克服本征型高分子材料的一些固有缺陷,得到低摩擦因数、高耐磨性、高承载力以及耐高温等优异特性的摩擦学复合材料。本文综述了功能性填料如碳基材料、过渡金属硫化物、微胶囊、软金属、陶瓷纳米颗粒、矿物盐以及自润滑高分子对复合材料的减摩抗磨效果及机理。同时,力学性能是保证聚合物材料服役性能和使役寿命的关键参数,也会对材料的摩擦学性能带来显著影响。本文还重点论述了纳米颗粒和纤维等填料对复合材料的增强和增韧机理。最后,展望了功能性填料对力学性能与摩擦学性能的协效作用,以及计算机模拟在复合材料摩擦学中应用的发展趋势。     

Characteristics of two-component epoxy modified bitumen

Coal tar bearing emulsions were used in the Netherlands as binder in anti-skid surfaces for runways because of their perfect adhesion and fuel resistance properties. They are however toxic and will not be allowed anymore after 2010. Therefore alternatives need to be developed. As one of the alternatives, two types of two-component epoxy modified bitumen have been investigated by means of direct tensile tests (DTT), relaxation tests (RT) and dynamic shear rheometer (DSR) tests. The effect of the curing temperature on the strength development of the epoxy modified bitumen was tested. The results show that the tensile strength increases with increasing curing time and temperature. DTT and RT results indicate that this new epoxy modified bitumen has a much higher tensile strength, cures faster than a bitumen emulsion as a binder. Furthermore, it shows a good stress relaxation even at lower temperatures. The curing speed and the ultimate tensile strength after full curing can be easily adjusted. The DSR results show that the complex modulus of this epoxy modified binder is less susceptible to changes in temperature. The results also suggest that this epoxy modified bitumen has better anti-crack properties at lower temperature and less permanent deformation than bituminous binders at higher temperatures. All these results shows that this type of two-component epoxy modified bitumen can be promising as a binder in anti-skid layers.     

Characterisation of high-performance cold bitumen emulsion mixtures for surface courses

Cold bitumen emulsion mixture (CBEM) is not yet widely used as a surface course around the world. In this study, 0/14-mm-size dense-graded surface course CBEMs have been investigated. The mechanical performance was evaluated in terms of stiffness modulus over 3 months and resistance to permanent deformation under three different stress levels (100, 200, 300 kPa), whilst durability evaluation was carried out in terms of resistance to moisture and frost damage. The study has also investigated the incorporation of low cement content (1%) with relatively sustainable by-product fillers, namely ground-granulated blast furnace slag (GGBS) and fly ash (FA) type 450-S on both mechanical and durability performance. A comparison has been carried out between the low and high cement content CBEM, as well as with respect to corresponding hot mix asphalt (HMA). The results revealed that the incorporation of GGBS and FA in CBEMs leads to superior performance, similar to CBEMs treated with high cement content and comparable to an equivalent HMA. Furthermore, GGBS replacement exhibited better performance than that of FA replacement. The findings suggest that the new sustainable types of CBEM can be developed for using as a surface layer for medium- to heavy-trafficked roads.