【作者】 李进；

【导师】 张玉贞；

【作者基本信息】 中国石油大学 ， 化学工程与技术， 2010， 博士

【摘要】 本文选用三种不同沥青进行实验室模拟老化,用三种不同再生剂对老化沥青进行再生。采用浊度滴定实验、溶解法、共混性研究、扩散实验和沥青材料实验等,并探讨添加不同再生剂对老化沥青胶体稳定性的影响规律,再生剂与老化沥青的相容性与共混性,再生剂与老化沥青的复合性质和不同再生剂在老化沥青中的扩散规律等。对沥青、老化沥青和再生沥青进行浊度滴定实验和四组分分析,实验结果表明:沥青随老化深度的增加,其胶体稳定性随之降低。四组分的含量变化影响沥青的胶体稳定性,其中沥青质含量变化对沥青胶体稳定性的影响最大。老化沥青通过添加合适的再生剂可以使沥青的胶体稳定性得到恢复,从而达到有效再生。芳香分含量高,沥青质含量低的再生剂再生效果好。用27种已知Hansen溶解度参数的溶剂通过溶解法确定老化沥青和再生剂的溶解度参数。运用MATLAB程序对溶解实验中可溶点进行球体模拟,得到模拟球体球心就是样品的Hansen溶解度参数。模拟结果与溶解实验结果的吻合度基本在80%以上。再生剂R3的δp和δh值较大,所以极性和氢键作用较强。再生剂R2、R3和复合再生剂A3与三种老化沥青的Hansen溶解度参数差较小,所以它们之间的相容性好。由于再生剂R1与三种老化沥青的Hansen溶解度参数之差大,所以再生剂R1与老化沥青的相容性较差。采用修正的Flory-Huggins方程计算老化沥青和再生剂的混合自由能并探讨它们之间的共混性。结果表明三种老化沥青的溶解度参数值和芳碳率均比相应的原料沥青高,而H/C则降低。再生剂R1的溶解度参数与三种老化沥青的溶解度参数之差大于1.909(J/cm3)0.5,且再生剂R1与加德士老化沥青在25℃时的混合自由能?Gm>0,故再生剂R1与加德士老化沥青的混合过程为非自发过程。三种老化沥青与R2、R3和复合再生剂在25℃的混合自由能?Gm<0,则混合过程均为自发过程。三种不同再生剂对老化沥青进行再生实验,得到的再生沥青满足高等级道路石油沥青技术要求(GB/T15180-2000)相应的沥青质量等级,但是再生剂R1再生的沥青抗老化性质较差,烘后质量损失接近1.0%。用针入度指数和粘温指数对再生沥青感温性进行评价。实验结果表明再生沥青在低温和中高温区的感温性均好于原料沥青,其中再生剂R3再生的再生沥青感温性较好;三种再生剂对再生沥青中温区的感温性影响无明显规律,再生剂增加了老化沥青的感温性;再生剂R1对再生沥青的高温区感温性有所降低,而再生剂R2和R3则是略有增加。再生剂、老化沥青和再生沥青的粘度性质满足复合理论,再生剂与老化沥青复合的粘度规律性强,可以通过内插或外延推算再生剂和老化沥青的用量。对再生沥青及其RTFOT残留沥青、PAV残留沥青进行SHRP分析,最终确定其路用性能等级。从动态剪切流变实验和弯曲梁流变实验结果看以看出:再生剂的加入使沥青的高温抗车辙能力略有降低但也基本能恢复达到新鲜沥青的性质;再生剂的加入增强了沥青的抗疲劳能力及抗低温开裂能力。再生沥青混合料配比设计是沥青刨除料热拌再生过程中的关键步骤。用两种再生剂对三种沥青刨除料热拌再生。对旧沥青进行性质分析和再生试验,再生沥青进行动态剪切流变实验。加入新集料调整再生集料级配,使再生集料级配满足规范要求。通过配比设计实验,得到再生沥青混合料配比设计各项参数均满足规范要求。在60℃和30℃时,再生沥青的动态剪切流变分析得到再生沥青材料的粘弹性得到有效恢复,两种再生剂再生的金华路和大勇街的再生沥青抗车辙性质好。在抗水损实验中,只有再生剂B再生的金华路沥青混凝土的残余稳定度小于75%,其残余稳定度为64.8%。回弹模量实验中再生沥青混凝土回弹模量大多在2000～4000MPa之间。再生剂B再生的沥青混凝土马歇尔稳定值与回弹模量均小于相应的再生剂A再生的沥青混凝土。不同再生剂在老化沥青中的扩散并用Fick扩散公式计算扩散系数,研究温度、时间、分子大小和极性对于扩散系数的影响。结果表明温度对于扩散系数有很大的影响,温度升高扩散作用加大;扩散时间增加,再生剂在沥青中浓度梯度变小,扩散系数减小;距初始界面距离大,浓度梯度小,相应扩散系数小;不同再生剂之间的扩散系数也有比较大的区别,这主要与再生剂中芳香分的含量和分子大小有关。再生剂在老化沥青中的扩散改变了老化沥青的性质,因此浓度对扩散速率的影响非常大。更多还原

【Abstract】 Three different asphalts were chosen to simulate the aging process in lab, and three different rejuvenators were used to recycle the aged asphalts. Turbidimetric titration, dissolution method and research of mixing properties were used to study the influence of adding different rejuvenators on aged asphalts colloidal stability, compatibility of rejuvenators and aged asphalts and the properties of them being compounded, and so on.The experiment of Turbidimetric titration and SARA(Saturants, Aromatic, Resins, Asphaltenes, SARA) analysis were taken on bitumen, aged asphalts and recycled asphalts. The results show that with the bitumen deep aging, its colloidal stability decreases. The changes of SARA influence the colloidal stability of the bitumen, and the asphaltenes is the most important factor. The colloidal stability of old asphalts could be renewed by adding proper rejuvenators. The rejuvenators with high aromatic and low asphaltenes are better.The solvents with Hansen parameters known were used to make sure the parameters of old asphalts and rejuvenators. The MATLAB program can be used to simulate the soluble points in experiments, through which the Hansen parameter were got. The join could be higher than 80% between simulation results and experimental data. Theδp andδh of rejuvenator R3 were higher, so the polarity and H-bond reaction are great. The Hansen parameters difference of rejuvenator R2、R3 A3 and three old asphalts is small, so the compatibility is good. Since the Hansen solvent parameters difference of R1 and three old asphalts is large, so the compatibility is bad. The Flory-Huggins Equation was used to calculate the mixture free energy of aged asphalts and rejuvenators. The results show that the solvent parameters and aromatic carbon ratio is higher than relative new asphalts and with low H/C. The Hansen solvent parameters difference of R1 and three old asphalts is higher than 1.909(J/cm3)0.5,and ?Gm at 25℃of rejuvenator R1 and Cartex aged asphalts is higher than 0.0 (?Gm>0), their process of mixing is not spontaneity. The ?Gm at 25℃of rejuvenator R2、R3 is higher than 0.0(?Gm<0), so they are spontaneous.The aged asphalts recycled by three rejuvenators meet the technical requirements of high way(GB/T15180-2000), however the anti-aging property of aged asphalts recycled by R1 is bad, the weight loss is almost 1.0% after aging. The Penetration Index and Viscosity Temperature Susceptibility were used to evaluate the temperature susceptibility of recycled asphalts. The experiments show that the recycled asphalts are better than new asphalts in low and mid-high temperature area, the asphalts recycled by R3 is better; there is no obvious law of the mid-temperature property, the rejuvenator improve the temperature sensitivity of recycled asphalts, however the rejuvenator R1 lowed the high temperature sensitivity, and the rejuvenators R2 and R3 increase a little. The viscosity of rejuvenator, aged asphalt and recycled asphalt satisfied the complex theory, the viscosity law of rejuvenator and aged asphalts is strong, the quantity of rejuvenator and old asphalts can be gotten by calculating. The SHRP analysis is taken on recycled asphalts, its RTFOT asphalts, PAV asphalts to make sure the performance grade. From experiment results of the DSR and BBR: the adding of rejuvenators low the anti-track property and improve the anti-cracking property of asphalts. The pavement design is the key step course of hot-mix recycling asphalt pavement. Two rejuvenators were used to recycle RAP. The property analysis and recycling experiments were taken on the old asphalts, the DSR experiments were taken on the recycled asphalts. The new aggregates were added to adjust the recycled aggregates, to satisfy the specification. After the design experiments, the parameters all satisfy the demands. At 60℃and 30℃the visco-elasticity can be recovered from the DSR experiments, the anti-track properties of Jinhua Road and Dayong Street recycled asphalts are good. In anti-water damage experiments, only the Marshall stability of Jinhua Road RAP recycled by B is lower than 75%, the remaining stability is 64.8%. The resilience modulus are mostly between 2000 and 4000MPa. The Marshall numbers of RAP recycled by B are all smaller than ones recycled by A. the diffusion of rejuvenators in old asphalts is also be studied.The Fick Equation is used to calculate the coefficients, the temperature, time, molecular size and polarity effects on diffusing are also studied. The results show that temperature has a great effect on diffusing coefficient, the action becomes stronger with higher temperature; the difference of concentrations is smaller, the diffusing coefficient becomes smaller; further the distance from the original level the concentration difference is smaller and so is the coefficient, the coefficients differences of different rejuvenator are great, that’s because of the differences of aromatic components and the molecular size. The diffusion of rejuvenators in old asphalts changed the property of old asphalts, so it has a great effect on the rate of diffusing.更多还原