Storage Stability of SBS-Modified Road Asphalt: Preparation,Morphology, and Rheological Properties

Abstract

The hot storage stability of styrene-butadiene-styrene triblock copolymer (SBS)-modified road asphalt can be improved significantly by reactive blending of SBS and asphalt under high share mixing at high temperature with elemental sulfur and vulcanization accelerator. The storage stability, morphology, and rheological properties were analyzed and evaluated by means of the hot storage test, fluorescent microscopy, and conventional and dynamic mechanical analysis using a dynamic share rheometer (DSR), respectively. The test results indicate that not only storage stability but also rheological properties of SBS-modified asphalt were enhanced by reactive blending of SBS and asphalt. Moreover, the addition of cross-linking agent resulted in the change in morphology of SBS-modified asphalt from a continuous asphalt phase with dispersed SBS particles to two interlocked continuous phases. The formation of a chemically cross-linked network enhanced the elasticity and deformation resistance of SBS-modified asphalt.     

Effect of different rejuvenators on the properties of aged SBS modified asphalt

The styrene-butadiene-styrene copolymer (SBS)–modified asphalt was aged by pressure aging vessel test. The effect of different content of rejuvenators on the physical and rheological properties of aged SBS-modified asphalt was investigated. The results showed that with the increase of the content, the physical and rheological properties of the aged SBS-modified asphalt are restored more significantly. Three kinds of rejuvenators were used to rejuvenate the properties of aged SBS-modified asphalt. It can be concluded that the improvement of rejuvenator-III on the properties of aged SBS-modified asphalt is the most obvious. The results also indicate that the rheological behavior of the aged SBS-modified asphalt is improved obviously by the rejuvenator.     

Investigation and Improvement of Storage Stability of SBS Modified Asphalt

Three different types of storage stability of SBS modified asphalts were investigated by hot storage test. It's found that during hot storage the performance of SBS modified asphalt deteriorated although phase separation didn't happen. Mechanism of storage stability of SBS modified asphalt was discussed. The different hot storage stability of three SBS modified asphalts could be well interpreted with the interface layer principle. Based on the interface layer principle, a new way that asphalt was chemically modified by SBS was put forward to improve hot storage stability and other using performances. The results indicated that the asphalt chemically modified by SBS had good hot storage stability and other using performances were significantly improved. Fluorescence microscopy was used to study SBS modified asphalt phase morphology, and the SBS chemically modified asphalt showed two interlocked continuous phases.     

Investigation and Improvement of Storage Stability of SBS Modified Asphalt

Abstract

Three different types of storage stability of SBS modified asphalts were investigated by hot storage test. It's found that during hot storage the performance of SBS modified asphalt deteriorated although phase separation didn't happen. Mechanism of storage stability of SBS modified asphalt was discussed. The different hot storage stability of three SBS modified asphalts could be well interpreted with the interface layer principle. Based on the interface layer principle, a new way that asphalt was chemically modified by SBS was put forward to improve hot storage stability and other using performances. The results indicated that the asphalt chemically modified by SBS had good hot storage stability and other using performances were significantly improved. Fluorescence microscopy was used to study SBS modified asphalt phase morphology, and the SBS chemically modified asphalt showed two interlocked continuous phases.     

沥青-SBS反应性共混改性

为提高SBS改性沥青的热储稳定性，提出了沥青－SBS反应性共混改性的方法，并讨论了沥青－SBS反应性混改性的机理。试验结果表明，反应性SBS改性沥青的热储存稳定性显著提高，同时使用性能明显改善。利用荧光显微照相技术研究了反应性SBS改性沥青微观结构，结果表明反应性SBS改性沥青具有SBS、沥青两相连续的空间网络结构。     

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).     

A Study on the Performance and Storage Stability of Crumb Rubber-Modified Asphalts

Abstract

Crumb rubber–modified asphalt (CRMA) with good storage stability was prepared using activated crumb rubber. The activation of crumb rubber was carried out by blending crumb rubber with polymeric compatibilizer in extruder to improve interaction between crumb rubber and asphalt. The softening point difference (SPD) and photomicrographs were used to reveal the storage stability of CRMA. The long-term storage stability test results indicate that the softening point difference of CRMA was below 2.5°C. The rheological characteristics of the binders were studied with a dynamic shear rheometer (DSR) and a bending beam rheometer (BBR). The results showed that the CRMA binders are possessed of the better resistance to permanent deformation at high temperature and cracking at low temperature than those SBS-modified and straight-run asphalts.     

环保型SBS改性阻燃沥青性能研究

采用氧指数测定法、动态剪切流变实验、弯曲梁流变实验和DSC-TG实验、扫描电镜(SEM)手段研究了环保型SBS改性阻燃沥青的性能;通过研究环保型阻燃剂对SBS改性沥青阻燃性能、物理性能、135 ℃运动黏度和高低温流变性能的影响确定了环保型阻燃剂的加入量;检测了环保型SBS改性阻燃沥青的环保性能。结果表明,环保型SBS改性阻燃沥青具有良好的阻燃性能、物理性能、热储存稳定性及环保性能,环保型阻燃剂可以提高SBS改性沥青的高温性能,但会影响低温性能;环保型阻燃剂的加入可以提高SBS改性沥青的热分解温度和开始燃烧温度,并且在沥青燃烧时可以减少烟密度及有毒烟气的释放。     

SBS／MMT复合改性沥青常规性能测试分析

利用苯乙烯-丁二烯-苯乙烯三嵌段共聚物（SBS）与蒙脱土（MMT）及其共混物分别对沥青进行了直接复合改性和共混物复合改性,测试了改性剂用量不同的SBS改性沥青、MMT改性沥青以及SBS与MMT质量比（m（SBS）／m（MMT））不同的共混物复合改性沥青的物理机械性能,同时还对不同m（SBS）／m（MMT）的SBS／MMT共混物复合改性沥青及SBS／MMT直接复合改性沥青的高温储存稳定性和相形态作了测试分析。结果表明,SBS／MMT共混物复合改性沥青的常规性能整体最优。     

SBS改性道路沥青的性能概述

综述了聚合物秘诀生沥青的发展情况及路用性能,并从流变性的角度介绍了ＳＢＳ改性沥青的性能,同时提出了ＳＢＳ改性沥青应用过程中存在的主要问题－－热储稳定性。     

化学法改性克拉玛依沥青研究

针对克拉玛依沥青难以改性，产品稳定性差等问题，本研究采用化学改性法，对比分析了4种基质沥青在改性前后的元素组成、红外光谱、族组成、分子量的变化以及SBS改性沥青的常规性质的差异。结果表明：相对于物理改性，化学改性不仅显著降低了SBS改性沥青的反应温度，而且还提高了SBS改性沥青的高温性能。     

沥青胶结料基本高温性能指标相关性研究

高温稳定性是沥青胶结料重要技术要求之一。针入度、软化点、60℃动力黏度和针入度指数是工程中最为常用的高温性能评价指标。为探究这些高温性能指标的区分度和关联性,对34种源于不同工程的沥青胶结料进行检测,基于聚类分析法和灰色关联分析法对试验数据进行分析。结果表明,60℃动力黏度指标相比针入度和软化点指标能够更有效地区分不同沥青胶结料的高温性能;70号基质沥青和高黏度改性沥青的60℃动力黏度与软化点关联度高,但SBS改性沥青60℃动力黏度与其他高温性能指标的关联度低;考虑到动力黏度能够客观表征流变特性,建议在实际工程中可将60℃动力黏度列为强制性指标。     

SBS改性沥青的相容性和稳定性机理

通过添加相容剂和稳定剂使苯乙烯－丁二烯－苯乙烯嵌段共聚物（SBS）在沥青中稳定分散，制备储存稳定性良好的SBS改性沥青，探讨其稳定机理，研究结果表明，相容剂能够溶胀SBS的硬嵌段－聚苯乙烯微区，使SBS在沥青中分散均匀；稳定剂能够引发SBS交联形成网络结构，使沥青接枝到SBS上，稳定SBS在沥青中的分散，从而得到宏观上均匀稳定的SBS改性沥青体系。     

油浆改质沥青与其SBS改性沥青性质关联研究

以70号沥青、减压渣油和催化裂化油浆为原料，制备配制沥青原料、油浆改质沥青和SBS改性油浆改质沥青，分析其性质和族组成，探讨了油浆改质沥青性质对SBS改性沥青性质的影响，并结合荧光显微照片，考察了SBS在油浆改质沥青中的分散状态和微观结构。结果表明：芳香分含量较高时，油浆改质沥青的性能较好，SBS与其相容性也较好，从而能够制备出性能较好的SBS改性油浆改质沥青；SBS改性缩合油浆改质沥青的性质优于SBS改性油浆改质沥青的性质，且达到了SBS改性沥青I-D级标准。     

Compatibility between SBS and Asphalt

The compatibility between SBS and asphalt was studied by molecule simulation and asphalt's basic capability testing. The results indicated that SBS and asphalt had different compatibility in the different SBS added amounts at different temperatures. Some compositions of the asphalt could enter an assembled polybutadiene segment. The effects of this phenomenon enhanced the Glass transition temperature. With high shear force effect, some compositions of the asphalt also could enter a polystyrene segment, which decreased the Glass transition temperature, but did not seriously disjoin the physical cross-linking point. When the mass fraction of SBS was 4%, SBS presented disperse spherical grain. However, when the mass fraction of SBS was over 8%, it formed a continuous phase. With the increasing mass fraction of SBS, the softening point and low temperature ductility would increase, and penetration and high temperature storage stability would decline.     

基质沥青与SBS相容性的预测

沥青与SBS的相容性是改性沥青的一个重要参数,相容性的优劣对于沥青能否与SBS共混制得性能良好的改性沥青产品,以及改性沥青能否保持良好的储存稳定性有重要的影响。相容性好的沥青容易与SBS共混形成稳定的胶体结构,制得稳定性良好的改性沥青产品;反之,则不利于SBS的稳定分散。如果能够事先预测SBS与沥青的相容性,则对于改性沥青的研究和生产具有指导意义。研究采用了两种方法预测基质沥青与SBS的相容性,一是借助溶解度参数计算方法,二是对比分析沥青的族组成与相容性的相关性。     

SBS改性沥青稳定机理的研究

通过加入相容剂和稳定剂来稳定SBS在沥青中的分散,制备贮存稳定性良好的SBS改性沥青,并探讨其稳定定理。研究表明,相容剂能够溶胀SBS的硬嵌段－－聚苯乙烯微区,有利于SBS在沥青中均匀分散,稳定剂能够引发SBS交联形成网络结构和沥青接枝到SBS上,稳定SBS在沥青中的分散,形成宏观均匀稳定的体系。     

反应性SBS改性沥青在华东地区的生产和应用

反应性SBS改性沥青是在热沥青当中,以SBS为改性剂,加入少量的增溶剂、偶联剂,采用物理和化学为一体的改性方法加工而成的改性沥青。它具有良好的路用性能、热储存稳定性和相对稳定的质量,并能长期高温储存,使离析指数保持在2.0C以下。     

Effect of nanoclay on performance of neat and SBS-modified bitumen and HMA

The aim of this research was to investigate impact of nanoclay on rutting and moisture damages resistance of neat and SBS-modified asphalt binder and mixture. 4% SBS was blended with 2% nanoclay and 6% nanoclay was used and compared with neat and 4% SBS-modified asphalt binder and mixes. Results of performing rotational viscosity, dynamic shear rheometer, repeated creep recovery, indirect tensile strength, and dynamic creep tests indicated nanoclay has positive impact on rutting and moisture damages resistance of neat and modified asphalt binder.     

废旧塑料橡胶复合改性沥青性能研究

鉴于塑料、橡胶改性沥青在国内外成功应用,对新型废旧塑胶复合改性沥青进行性能研究。通过沥青常规试验、DSR试验、BBR试验以及微观观测试验,对其感温性、高温稳定性、低温抗裂性、存储稳定性、抗老化性能等进行评价。研究表明,塑胶复合改性沥青高低温性能满足PG88-28要求,感温性能优于常用的SBS改性沥青,存储稳定性、抗老化性能与其相差不大;通过微观观测试验发现,改性剂与沥青体相互构成立体网状链接结构,是复合改性沥青稳定存在、高低温性能等优越的主要原因。