FCC油浆糠醛抽出油改善胶粉改性沥青性能的研究

FCC油浆糠醛抽出油富含芳香组分,是良好的道路沥青调合分。用FCC油浆糠醛抽出油溶胀预处理胶粉制备改性沥青,考察了胶粉含量和胶油比双因素对改性沥青性能的影响,同时使用扫描电子显微镜和荧光显微镜对胶粉和改性沥青的微观形态进行分析。研究结果表明,使用FCC油浆糠醛抽出油溶胀预处理胶粉可制备出性能良好的改性沥青。尤其是随着胶粉含量的增加,沥青的软化点和低温延度明显得到了改善。当胶粉质量分数为25％,胶油比控制在4～7时改性沥青的基本性能和老化性能良好,热储存稳定性最佳。     

The influence of nanoclay on the performance properties and moisture susceptibility of rubberized asphalt mixture

The authors investigated the effect of nanoclay (NC) on the performance properties and moisture susceptibility of rubberized asphalt mixtures. Two percent crumb rubber modifier (CRM) and NC in both combined and separate modes and the effects of each additive on bitumen performance were examined through administering tests of penetration grade, softening point and temperature susceptibility. Also, indirect tensile strength tests in both dry and saturated states were performed to allow for measuring the moisture susceptibility of asphalt mixtures. Moreover, the effect size of both additives on improving the bitumen performance and asphalt mixtures was assessed by running analysis of variance method and sensitivity analysis. The results of the laboratory test and statistical analyses revealed that CRM and NC improved the properties of bitumen and asphalt mixtures. This improvement was associated with the content and type of the additives applied, and also bitumen and asphalt mixtures had the best performance in presence of a combination of CRM and NC.     

Laboratory investigation of rutting performance of warm mix asphalt containing high content of reclaimed asphalt pavement

In this research, the influence of warm mix additives on the properties of warm-mix asphalt (WMA) containing recycled asphalt pavement (RAP) was investigated and compared with the same graded hot-mix asphalt (HMA). WMA mixtures were produced using Sasobit and Zycotherm as organic and chemical WMA additives, respectively. Mixtures were prepared containing RAP in different proportions (0%, 25%, 50% and 75 % of total aggregates). Dynamic creep and wheel track tests were used to investigate the resistance of specimens to permanent deformation. Zycothem WMA mixtures showed less resilient modulus and rutting resistance than Sasobit WMA mixtures. It was also concluded that increasing the amount of RAP in mixtures improves resilient modulus and rutting resistance of all mixtures.     

橡胶沥青的动态剪切流变试验分析

通过动态剪切流变试验,对路用橡胶沥青结合料的流变性能进行了分析。试验采用2种不同类型的基质沥青以及4种不同含量的胶粉制备成5种不同类型的橡胶改性沥青,使用动态剪切流变仪分别对原样、短期老化以及长期老化三种状态的试样进行了测试,分析了各粘弹性参数随橡胶沥青类型变化的规律。同时也对比分析了各种类型的胶粉改性沥青的高温抗车辙性能和抗疲劳性能。试验结果表明,橡胶胶粉含量在15%～21%范围内时,橡胶沥青的高温和中等温度下疲劳性能均随橡胶胶粉含量的增加而提高。     

加工工艺条件对胶粉改性沥青性质的影响

用废汽车轮胎粉生产改性沥青不但可以提高沥青的使用性能。还可以解决其"黑色污染"问题。以欢喜岭沥青为原料,采用湿法生产胶粉改性沥青过程中,剪切温度、剪切速率、剪切时间和胶粉加入量等都会影响胶粉改性沥青的性质。     

近年废胶粉改性道路沥青的研究

介绍了近年道路沥青方面的肢粉研究情况。主要有：胶粉的添加及工艺条件变化对沥青性能的影响，肢粉与沥青的相容性，肢粉改性沥青老化以及改性机理等国内外研究现状及其简要评论。     

脱硫过程对废胶粉改性沥青粘度的影响

通过对高温反应和存储时间的试验研究,验证了脱硫程度对废胶粉改性沥青性能有着重要的影响.并通过添加活化剂来加速脱硫反应的进行,从而使废胶粉改性沥青获得更好的应用性能.     

复配废橡胶粉与岩沥青改性沥青粘度的实验室研究

研究了废橡胶粉和岩沥青对沥青粘度的影响。结果表明,在基质沥青中掺加18％橡胶粉时,177℃的粘度处在1．5—4．0Pa·s范围内,拌和时间以60min左右为宜。复合掺加18％橡胶粉和3％岩沥青时,对60℃粘度和177℃粘度增大都较为显著,且均满足粘度指标要求。     

微波辐射活化废胶粉改性沥青存储稳定性研究

基于现有研究，对微波辐射活化废胶粉改性沥青的存储稳定性进行了较为深入的研究。通过离析试验研究了微波辐射活化废胶粉改性沥青在高温存储过程中的离析规律，利用软化点指标研究了微波辐射活化废胶粉改性沥青的的常温存储稳定性能。另外，研究了微波辐射活化废胶粉放置不同时间对改性沥青存储稳定性的影响。     

Moisture susceptibility of warm mixed-reclaimed asphalt pavement containing Sasobit and Zycotherm additives

In this research, the influence of Sasobit and Zycotherm on the properties of reclaimed asphalt pavement (RAP)-warm mix asphalt (WMA) was investigated. Moisture susceptibility was evaluated applying the resilient modulus ratio, the indirect tensile strength ratio, and the fracture energy ratio. Laboratory testing results indicated that Zycotherm mixtures had more resistance to moisture damage than Sasobit WMA and hot mix asphalt (HMA) mixtures. The stiffness of mixtures increased dramatically by increasing the amount of RAP and using Sasobit exacerbated this problem.     

三种改性沥青动粘弹性能的研究

运用动态剪切流变仪分别评价了橡胶沥青、SBS改性沥青、SBS／橡胶粉复合改性沥青的高温性能。通过应变扫描,确定了三种改性沥青的线粘弹性范围。通过频率扫描,评价了三种改性沥青的粘弹性能。结果表明,橡胶沥青具有优良的高温性能,SBS改性沥青具有良好的疲劳性能。     

废胶粉改性沥青性能影响因素研究

分析了制备工艺、胶粉粒径以及外加添加剂对胶粉改性沥青常规使用性能和稳定性的影响。结果表明:在一定的范围内,胶粉粒径细,对沥青性能的改善较好;加入相容剂可改变沥青胶体体系的溶剂化层的结构和性质;交联剂的加入,增大了体系的稳定性。     

Investigation of fatigue life of asphalt mixtures based on the initial dissipated energy approach

The present research study addresses the fatigue life of different asphalt mixtures by means of 4PBF test. To this end, the fatigue behavior of unmodified asphalt mixtures and modified mixtures with styrene-butadiene-styrene polymer and crumb rubber as modifier were investigated in low and medium strain levels. Results showed that there is an excellent correlation between the fatigue lives of different asphalt mixtures in terms of the dissipated energy approach. It can be observed from result that the amount of initial dissipated energy at the 50th loading cycle predicted the fatigue life of asphalt mixtures without performing millions of loading cycles. Furthermore, the initial dissipated approach provides more reliable results from fatigue life of asphalt mixtures in comparison to the traditional fatigue tests.     

微波胶粉比表面积对橡胶沥青流变性能的影响

通过考察不同微波辐射时间对胶粉活化处理并制备胶粉改性沥青的效果,研究微波辐射对胶粉表观特性与其改性沥青流变性能的影响。采用气体吸附仪、动态剪切流变仪分别测定胶粉活化前后的比表面积及改性沥青的流变性能,并将胶粉的比表面积与沥青流变性能进行关联。在此基础上,结合扫描电镜,从微观角度揭示活化胶粉对沥青流变性能的影响机理。结果表明:在测定时间内,微波辐射使得胶粉表面变得蓬松,孔隙增多,比表面积增长显著;一定时间范围内(60～120s)的微波辐射对胶粉改性沥青的高温抗车辙能力有显著影响;胶粉微波活化后其比表面积与改性沥青流变性能之间有很好的相关性,胶粉比表面积越大,其复数剪切模量越大,相位角越小,沥青的高温抗变形能力越好。     

速溶胶粉改性沥青混合料的研究

橡胶胶粉的三维化学交联结构使其难以在沥青混合料中分散,限制了其在道路中的应用。采用预先高效解交联方法制备了速溶胶粉,并通过干法和湿法工艺制备了速溶胶粉改性沥青混合料。对比分析了速溶胶粉和原胶粉改性沥青混合料的体积指标、抗飞散能力和马歇尔稳定度等性能。通过观察胶浆的微观结构,比较了不同胶粉的分散情况。进一步探究了油石比对速溶胶粉改性沥青混合料性能的影响。结果表明,与原胶粉相比,速溶胶粉在沥青混合料中分散地更细(微米尺度)、更均匀,速溶胶粉改性沥青混合料更易压实、粘结性能更佳。采用速溶胶粉取代原胶粉可以降低胶粉改性沥青的加工温度,干法时结合焖料工艺也可进一步降低沥青用量,部分替代沥青。     

废胎胶粉改性沥青影响因素探讨

采用斜交胎和子午胎两种废胎胶粉对基质沥青(中海70号沥青和SK70号沥青)进行改性,试验研究结果表明:胶粉掺量为20%,搅拌温度为180℃,废胎胶粉为斜交胎时,改性沥青的高温稳定性、低温抗裂性、弹性恢复性能较基质沥青有明显提高;胶粉粒径可根据技术经济性选择合适的粒径等级;斜交胎胶粉的改性沥青性能明显好于子午胎胶粉;从高温性能、感温性能及弹性性能指标来看,中海70号改性效果比SK70号沥青差,但其低温指标略好。     

SBS复合改性橡胶沥青试验研究

为了研究废旧橡胶粉和SBS复合改性沥青的结果,分析了聚合物改性沥青的改性机理,采用20%外掺橡胶粉,分别添加0.5%、1%、1.5%、2%的SBS进行复合改性,测试比较了复合改性橡胶沥青和普通橡胶改性沥青的主要指标,并研究了SBS掺量对橡胶沥青的影响,结果表明,复合改性橡胶沥青能达到比普通橡胶沥青更好的高低温性能。     

High-temperature performance and microstructure of composite modified hard asphalt

Composite modified hard asphalt (CMHA) was prepared by four-step high-speed shearing method adding crumb rubber, styrene-butadiene-styrene (SBS) copolymer, and hard asphalt to QHD AH-70 neat asphalt. The high-temperature performance and microstructure of CMHA were evaluated by rotational viscometer, fluorescence microscopy, and infrared spectroscopy, through which the modification mechanism was proposed. The results show that the shearing time had great influence on the high-temperature performance of CMHA. A significant variation in phase morphology of CMHA during preparation was observed. It is found that phase morphology was converted from a continuous asphalt phase with dispersed polymer phase to two twisted continuous phases, then to a continuous asphalt phase with dispersed polymer phase again. Preparation of CMHA was a complex physical and chemical process. A fraction of SBS took part in the chemical reaction and others were dispersed in net structure, which is beneficial for workability and performance of asphalt.     

水滑石/废橡胶粉复合改性沥青的制备及其性能研究

以克拉玛依90号沥青作为基质沥青、废橡胶粉和水滑石（LDHs）作为改性剂,制备了LDHs/废橡胶粉复合改性沥青,在废橡胶粉加入量不变的条件下,考察LDHs加入量对复合改性沥青的物理性能、抗紫外老化性能和流变性能的影响。结果表明：当废橡胶粉加入量（w）为15%时,随着LDHs的加入,复合改性沥青的软化点升高,针入度和延度有所下降,两种改性剂相互结合,使复合改性沥青的物理性能得到改善,并且满足国家聚合物改性沥青标准的要求,考虑到改性剂成本,选取LDHs加入量（w）为3%～4%;LDHs的加入使复合改性沥青的软化点增量减小,残留针入度比和延度保留率上升,表明LDHs可明显提高复合改性沥青的抗紫外老化性能;LDHs的加入可使复合改性沥青复数模量和车辙因子增加,相位角下降,说明LDHs可提高复合改性沥青的抗车辙性能。     

Evaluation of performance properties of 50% recycled asphalt mixtures using three types of rejuvenators

Abstract

In this study Cyclogen, Rapiol and waste cooking oil was used as rejuvenators to improve properties of aged bitumen. The effects of these rejuvenators on asphalt mixtures containing 50% of reclaimed asphalt pavement specimens was evaluated using dynamic creep, resilient modulus, low temperature fracture energy and moisture susceptibility tests and the results was compared to recycled mixtures without rejuvenator and control HMA mixtures. The results showed that the rejuvenators are effective in alleviating the aging effect of RAP bitumen. Waste cooking oil performed better than other studied rejuvenators followed by Cyclogen and Rapiol. However, moisture resistance was impaired when rejuvenators were used.