微藻油改性沥青耐老化性能研究

为缓解石油沥青短缺局势,探索微藻油用于沥青改性可行性及改性沥青长期性能,将微藻液经降解、离心、萃取得到微藻油并制备改性沥青。通过不同微藻油掺量下改性沥青延度、软化点和黏度确定微藻油最佳掺量,通过高低温流变试验、混合料路用性能试验分析微藻油改性沥青经旋转薄膜烘箱(RTFOT)短期老化、压力老化容器(PAV)长期老化和紫外老化后性能变化并与SBS改性沥青对比,借助红外光谱分析微藻油改性沥青分子结构组成。结果表明:微藻油掺量为30%(外掺质量分数)时,改性沥青延度达到最大值,软化点和黏度满足改性沥青要求;微藻油改性沥青和苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性沥青经RTFOT短期老化后性能差异不显著,微藻油改性沥青耐PAV长期老化和耐紫外老化性能优于SBS改性沥青,尤其是耐紫外老化性能更优。红外分析表明两种改性沥青均含有乙烯基双键、芳香族C—H、甲基和亚甲基等类似成分,但芳香族C—H、伸缩C—C成分含量存在差异。微藻油改性沥青比SBS改性沥青增加的酰胺不饱和基团和羧基利于改性沥青形成网络分子结构。     

活化废轿车轮胎胶粉及其改性沥青的基本性能

采用双螺杆挤出机辅以活化剂制备活化废轿车轮胎胶粉(GTR),用其改性沥青或与苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)复合改性沥青。研究了活化GTR的溶胶、凝胶含量,考察了活化GTR改性沥青和活化GTR/SBS复合改性沥青的基本性能及微观形貌。结果表明,热剪切以及添加活化剂均能提高GTR的溶胶含量,使脱硫降解程度增大;用活化GTR改性沥青,改性沥青的针入度大幅增大,软化点、弹性回复、黏度明显降低;用活化GTR/SBS复合改性沥青,随着活化GTR含量的增大,改性沥青的软化点升高,针入度、延度、弹性回复降低,但经旋转薄膜老化后延度提高,耐老化性能提高;活化GTR在沥青中的粒径明显减小,分散性得到改善,而活化GTR/SBS复合改性沥青时,GTR均匀分散于SBS的网络结构中。     

煤沥青与石油沥青共混改性及其热解特性

考察了不同添加量的煤沥青四氢呋喃萃取物(THFS)对石油沥青的改性,随着THFS添加量的增多,改性沥青针入度降低,软化点升高,延度下降,参照英国标准(BSI BS—3690)得出最佳添加量为8%。利用TG-FTIR、FTIR对改性沥青进行了表征,结果表明:THFS、改性沥青的失重率大于基质沥青70的失重率; THFS在700～900cm^-1处芳香烃类的透射峰强度明显强于基质沥青与改性沥青;沥青老化后在2953cm^-1和1377cm^-1(—CH₃)、1461cm^-1和2924cm^-1(—CH₂—)处透射峰逐渐增强;1600cm^-1(C=O和苯环C=C)透射峰逐渐增强;沥青热解半焦中的脂肪烃类物质含量较少,主要以高度缩合的稠环芳香烃类物质为主;沥青在老化过程中主要发生了氧化、裂解、加成、聚合、缩合等反应。     

响应面法优化制备LDHs-CRMA复合改性沥青及其表征

采用熔融共混法,以克拉玛依90#沥青为原料,Mg-Al水滑石(LDHs)与废橡胶粉(CR)作为改性剂,制备了具有抗紫外老化性能的水滑石/废胶粉复合改性沥青(LDHs/CRMA),并对其软化点、针入度指数(PI)、延度进行了测试。通过Hassan数学方法将三个指标"归一化"得到总评"归一值",采用响应面分析法建立总评"归一值"与各因素之间的Box-Behnken数学模型,得到了LDHs/CRMA的最优制备工艺条件为:剪切温度173℃、剪切时间89 min、剪切速率3500 r/min。通过紫外老化模拟实验对复合改性沥青的抗老化性能进行了评价,结果表明,引入水滑石可以减少沥青老化过程中含氧官能团的产生,抗紫外老化性能得到了明显提高。     

塔河沥青表征研究

采用红外分析,核磁共振等高等仪器对塔河沥青进行了分子结构的表征,对塔河沥青的四组分进行了分析,并采用布朗-拉德纳法计算了老化前后塔河沥青四组分的芳香度.结果表明:塔河沥青具有低温延度低,抗老化性能差的特点.     

甘肃省沥青路面长期老化后沥青微观分析研究

选择了道路石油沥青、实验室Pressure Vessel Aging(PAV)老化及沥青路面长期老化沥青作为研究对象,分析可知与基质沥青及实验室老化沥青相比,SK90#沥青在经过路面长期老化后,沥青的力学性能发生了明显的变化,表现为针入度与延度下降,软化点与粘度升高.通过傅里叶红外变换光谱和凝胶渗透色谱分析可知,沥青在老化过程中发生氧化发应,生成羰基和亚砜基官能团,且小分子链减少,大分子链增加;运用热重分析仪测定了沥青老化前后的热稳定性,发现老化前后沥青的热稳定性能基本保持不变.     

春风减渣改质塔河减渣制取60#道路沥青效果

塔河减渣（THVR）直接生产合格道路沥青存在技术瓶颈。本文用调和工艺,以塔河减渣为基质沥青,在荆门油浆、荆门抽出油及春风减渣3种不同种类的调和组分中优选出新疆春风减渣（CFVR）为优质软组分,对THVR改质制备60^#道路沥青的效果进行考察,建立基于正庚烷沥青质含量的沥青热老化动力学模型,并对改质前后沥青四组分进行平均分子结构表征。结果表明：与THVR相比,CFVR热老化性能及低温性能较好,但感温性能较差,添加40% CFVR的调和沥青TH-CF-40可满足道路石油沥青60^#标准。TH-CF-40老化速率较小,老化反应活化能E_a为102.00kJ/mol,较THVR为高;其饱和分链长为14.44,较THVR短;芳香分、胶质及沥青质芳碳率f_A分别为0.29、0.42、0.46,芳环与环烷环之比R_A/R_N分别为1.24、2.65、2.93,平均侧链长度L分别为6.78、6.09、5.40,均向CFVR趋近,从而使得调和沥青的抗热老化性能及低温延展性有所提高。采用该工艺有助于减少塔河减渣焦化处理量,提高塔河减渣的利用水平,研究结果为拓展春风优质沥青的更高效利用提供理论指导,具有学术意义和应用前景。     

纳米有机膨润土/丁苯橡胶复合改性沥青的制备及性能

以纳米有机膨润土和丁苯橡胶(SBR)制备复合改性沥青,并考察了复合改性沥青的针入度、软化点、延度、储存稳定性及流变性能,同时对比了液体SBR和粉末SBR对复合改性沥青性能的影响.结果表明,复合改性沥青中,纳米有机膨润土的最佳质量分数为4％.随着SBR用量的增加,沥青的针入度降低,软化点升高,延度先增大后减小.粉末SBR...     

阻燃沥青热老化过程中族组成变化研究

通过研究阻燃沥青在热老化过程中族组成的变化,探讨其老化后使用性能变差的主要原因.实验以辽河AH-70#沥青为基质沥青,按一定比例加入阻燃剂、抑烟剂和调和剂进行剪切,制备阻燃沥青,采用薄膜烘箱法模拟阻燃沥青老化过程,研究族组成的变化.实验结果表明:在相同老化温度下,随着老化时间的延长,饱和份、芳香份和胶质含量下降,沥青质...     

Preparation of hyperbranch-structured polyester fiber via thiol-ene click reaction under UV light irradiation for asphalt binder modification

This study reports the application of UV induced “thiol-ene click reaction” by coupling the covalent bonds of venyl-terminated dendritic polyester (VTDP) and polyester (PET) fiber and resulting in the fabrication of hyperbranch-structured PET named as VTDP-PET fiber. The PET fiber or VTDP-PET fiber as additives were blended with styrene-butadiene-styrene modified asphalt (SBSMA) to prepare fiber/SBSMAs. Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry, and X-ray photoelectron spectroscopy characterizations indicated that VTDP-PET fiber was linked with spherical three-dimensional dendritic molecular structure. Cone penetration, dynamic shear rheometer, multistress creep recovery, and thermogravimetric analysis tests showed that VTDP-PET/SBSMA exhibited enhanced resistance to flow, viscoelasticity, resistance against rutting, and thermal stability as compared to those of PET/SBSMA. The newly designed PET fiber and VTDP-PET fiber can be envisioned as effective alternative candidate for the fabricated of modified SBSMA with enhanced performances for practical applications in construction and highway industries.     

Quantitative evaluation of asphalt blending characteristics in epoxy-modified hot recycled asphalt mixtures based on 3D confocal fluorescence technology

This study proposes a novel method to quantitatively evaluate the blending effect between aged asphalt and epoxy asphalt in epoxy asphalt-modified hot recycled asphalt mixture, based on three-dimensional confocal fluorescence microscopy technology. Samples of epoxy asphalt-modified hot recycled asphalt mixtures were prepared in a laboratory using new aggregates, epoxy asphalt, and reclaimed asphalt pavement materials that were simulated in the laboratory by subjecting new asphalt mixtures to a short-term and long-term aging process. Cube-shaped stone aggregates were designed to distinguish between new aggregates and reclaimed aggregates. The distribution of epoxy resin in the epoxy asphalt-modified hot recycled mixtures was tracked using a laser scanning confocal microscope. To address the depth attenuation issue caused by light absorption and scattering, as well as the overall intensity differences resulting from field depth differences and attenuation morphology, a depth compensation function and a feature weight allocation method were proposed. Results from the above method indicated that the degree of blending (DoB) ranged from 65% to 75% on the surface of new aggregates but from 45% to 70% on the surface of reclaimed aggregates. Most of the old asphalt still adhered to the surface of reclaimed aggregates after migration. The proportion of epoxy asphalt in the outer layer of asphalt film on new aggregates is higher than that on reclaimed aggregates. The DoB between the asphalt binders significantly decreased as the aging degree increased. Increasing the epoxy content reduced the viscosity of the epoxy asphalt and effectively improved the DoB between the new and old asphalt binders.     

CPE系列聚合物改性路用沥青

研究了氯化聚乙烯(CPE)系列聚合物体系对改性沥青性能的影响．以及CPE含量、母料比例等对改性沥青的影响。实验结果表明．母炼胶法制备的改性沥青能够取得较好的效果。通过对CPE体系和CPE—g—MAH体系的比较．能直观的看到界面相容性对改性沥青起着至关重要的作用，使改性沥青呈现较好的延度、针入度和软化点。同时。对改性沥青的工艺进行了探索。     

道路老化沥青性能再生研究

道路沥青在使用后将会发生老化现象,老化后沥青的组分发生了改变,在性能上表现为软化点上升,针入度降低,延度降低等。文章通过对老化沥青组分组成进行分析,通过改变老化沥青组分达到沥青再生的目的,研究表明通过掺加沥青和再生剂来进行复合再生要比单纯的采用一种办法再生具有更好的效果。再生后的沥青三大指标符合路用沥青的使用标准,完全可以用于铺筑新道路的使用,甚至可以通过添加改性剂达到改性沥青的标准。     

SBS改性沥青的结构与性能

通过动态黏弹性能、结构分析和沥青基本性能测试研究了SBS和沥青之间的相容性,以及SBS用量对改性沥青的结构与性能的影响。结果表明,SBS与沥青有一定的相容性,沥青中的某些组分可进入SBS的聚丁二烯(PB)链段区域。使PB的玻璃化转变温度升高,在高剪切力作用下也可进入聚苯乙烯(PS)链段,降低了PS的玻璃化转变温度,但不会使PS物理交联点发生严重解体。当SBS质量分数为5％时,SBS在沥青中呈彼此分离的球状颗粒;当SBS质量分数达到7％或以上时,则形成连续相。随着SBS质量分数的增加。改性沥青的软化点和低温延度升高,针入度和高温贮存稳定性下降。     

苯乙烯-丁二烯-苯乙烯嵌段共聚物改性沥青的老化性能

考察了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)和加入含硫稳定剂的SBS改性沥青老化后的动态力学性能、黏度变化和低温物理性能。结果表明,SBS与含硫稳定剂的加入改善了老化后沥青的高温性能;老化后的改性沥青表现出更好的高温刚性,蠕变劲度降低,蠕变速率增大,老化后沥青的低温性能提高,且长期使用性能良好。     

Using SBS/terpene-styrene resin blends as a novel high-viscosity asphalt modifier

To improve the inferior stability in high-viscosity asphalt prepared using styrene-butadiene-styrene block copolymer (SBS) and to simplify the preparation process, a novel high-viscosity modifier (STP) was prepared with SBS, terpene-styrene resin (TSR) and plasticizer. Its inherent properties, optimal dosage, and modification effect were investigated. The results show that STP has lower component melting temperature and stronger polarity, combined with good thermal stability, ensuring that STP possesses a better modification effect on asphalt. 14.5–17.6 wt% was determined as the appropriate content of STP. The incorporation of STP improved the rutting resistance and elasticity percentage of the asphalt. The zero shear viscosity (ZSV) of asphalt fitted by the Carreau model showed that STP increased the cohesion of the asphalt system and improved the high-temperature deformation resistance. The small non-recoverable creep compliance value proves that the STP high-viscosity asphalt (STP-HVA) exhibits excellent resistance to permanent deformation at high-temperatures while displaying low-stress sensitivity and achieving an extremely heavy traffic rating. STP confers greater flexibility to asphalt to eliminate low-temperature cracking phenomenon. Smaller CMAI and PAAI values demonstrate that STP-HVA exhibits outstanding aging resistance. TSR effectively improves the compatibility of SBS and base asphalt, and STP particles are finely dispersed and uniform. The preparation process is mainly physical modification, accompanied by chemical reactions.     

再生沥青的热老化研究(Ⅱ)——再生沥青热老化过程中族组成变化的研究

通过对不同老化温度与不同老化时间下薄膜烘箱老化后族组成变化的研究 ,发现再生沥青的族组成随老化的进程发生改变 :老化时间延长 ,饱和分质量分数不变或略有减少 ,芳香分质量分数总是降低 ,胶质质量分数变化复杂 ,沥青质质量分数总是升高。对变化规律与原因进行了详细的讨论     

Study on percolation phenomena and mechanism of enhanced asphalt by polymers

Abstract

The properties of asphalt modified by styrene–butadiene–styrene, polyvinyl acetate and waste crumb rubber separately in a wide range of polymer loadings were studied in this paper. In analysing the relationship between polymer loading and modified asphalt properties, we found that the ductility of polymer modified asphalt measured at 5°C exhibited a percolation phenomenon, that is, as the loading of polymer exceeded a critical value, the ductility of modified asphalt changed abruptly. Furthermore, a percolation threshold differential existed. A rubber processing analyser, an optical microscope and a fluorescence microscope were used to characterise the microstructure of polymer modified asphalt and validate the occurrence of a polymer network in modified asphalt as a function of polymer loading. The percolation phenomenon of polymer modified asphalt was found to be associated with the polymer network in modified asphalt and can be well explained by the percolation mechanism of rubber toughened plastics.     

Preparation of β-cyclodextrin/SBS modified asphalts for the improvement of anti-aging,rheological property,and storage stability

Styrene-butadiene-styrene (SBS) modified asphalt (SMA) has been widely used in road engineering for decade. However, the phase separation of SMA was obvious during the transport and SBS degraded after aging. To resolve these problems, β-cyclodextrin (β-CD) was used to modify SMA in this work. Conventional properties, storage stability, the effect of short-term aging on the morphology, and rheological property for SMA and β-CD/SMA were investigated. The softening point of modified asphalt reached to the maximum of 66.7°C when 1 wt% β-CD was added to SMA, where the penetration had shown the minimum of 80.8 dmm. In addition, the ductility of β-CD/SMA increased to the maximum of 797 mm when the content of β-CD was increased to 5 wt%. Furthermore, incorporation of β-CD improved the storage stability of SMA. Importantly, the aggregation of SBS was observed in β-CD/SMA, but modifiers distributed uniformly after a short-term aging. The rutting resistance and antiaging performances of SMA were also improved by the addition of β-CD. Considering the comprehensive properties of modified asphalt, the optimum content of β-CD was found to be 2 wt%.     

Laboratory investigation of the properties of asphalt modified with epoxy resin

Epoxy asphalts were prepared by mixing styrene–butadiene–styrene (SBS) modified asphalt with epoxy resin. The curing process and morphology of epoxy asphalts were characterized by infrared spectroscopy and fluorescent microscope, respectively. The effects of epoxy resin contents, ratio of curing agent to epoxy resin and curing temperature on properties of epoxy asphalt were investigated. Results indicated that epoxy resin and epoxy asphalt showed similar curing efficiency. Epoxy asphalts can be cured at 120 or 60°C and its viscosity at 120°C can meet the demands of asphalt mixture mixing and paving. The chemical reaction of epoxy resin in epoxy asphalt is slow and reaction occurs not only with the curing agent but also carboxylic acid in epoxy asphalt. The microstructure of epoxy asphalt transforms from the dispersed structure to networks structure with epoxy resin content increasing and phase transition starts when 30 wt % epoxy resin present in asphalt. The softening point and tensile strength of epoxy asphalt increased with epoxy resin contents increasing. The softening point and tensile strength of epoxy asphalt were markedly improved when epoxy resin content was more than 30 wt %, which is attributed to formation of continuous structure of epoxy resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009