Evaluation of rutting potential for asphalt concrete mixes containing copper slag

Copper slag (CS) is a by-product of the copper extraction process, which can be used as coarse and/or fine aggregate in hot mix asphalt (HMA) pavements. This study used CS as a replacement of the fine aggregate with a percentage of up to 40% by total aggregate weight. The objective of this study was to evaluate the effect of CS on the rutting potential of the asphalt concrete mix using two methods. One method is based on the Dynamic modulus |E*| testing result. Actual pavement temperature data from a test section were used with the developed |E*| master curves. EverStressFE finite element program was used to perform a linear elastic load-deformation analysis for a pavement section and to determine the vertical resilient strain in a 40-mm HMA surface layer. The M-E PDG permanent deformation model was used with and Excel Visual Basic for Applications code to predict the accumulated rutting for different CS mixes for 10 million ESALs. The other method used the data from the flow number (FN) test. Based on the |E*| approach, the results indicated that adding 5% CS in the mix increased the predicted rutting from 0.59 to 0.98 mm at 10 million ESALs (increase by 68%). When 40% CS was used, rutting increased by more than 700% compared with the control mix. After analysing the FN results with the Francken model, the results indicated a decrease in FN as CS content is increased, indicating higher rutting potential. The decrease in FN ranged from 9% for 5% CS to 95% for 40% CS. The mixes containing up to 10% CS satisfied the minimum FN criteria for rutting. A calibration process for the M-E PDG distress prediction models that allows the use of waste and by-product materials such as CS should be considered in the future.     

沥青胶浆流变性能指标影响因素的灰色关联分析

针对沥青胶浆流变性能评价指标的影响因素,采用灰色关联度分析方法,分析了不同剪切应力水平、不同角速度、不同温度和粉胶比对沥青胶浆流变性能指标的影响程度,为沥青混合料的优化设计提供理论依据。     

高速公路沥青路面车辙机理分析

根据工程实践,介绍了高速公路沥青路面的车辙病害与类型,进行了路面结构的应力计算,分析了沥青路面结构内部剪切应力分布的规律及其路面发生流动变形的机理,提出了具体的建议,以减少车辙的发生。     

高温与重载对沥青路面的影响

分析了车辙对沥青路面的危害,介绍了高温对路面的影响,重点探讨了重载对沥青路面半刚性基层,路表弯沉,疲劳寿命,车辙四方面的影响,以引起相关设计人员的重视,从而及时采取措施以延长路面寿命。     

Effect of temperature on geosynthetic rutting performance in asphalt pavement

In this research study, a 3D finite element model using ABAQUS software is used to evaluate the rutting performance of reinforced asphalt pavement. In this research study, the effects of three types of geosynthetic layers on the optimum location are studied at temperatures of 20°C, 40°C, and 50°C. According to the model analysis, the middle of asphalt layer is determined as the optimized location of geosynthetic layers in the pavement structure. The results showed that the effect of geosynthetic layers on rutting performance increased with increasing elastic modulus of geosynthetic at high temperature of pavement.     

基于灰色关联度法的SBS改性沥青车辙因子影响因素分析

为了分析原材料对SBS改性沥青车辙因子的影响,课题采用五种基质沥青、五种SBS改性剂和五个不同的SBS改性剂掺量,设计了3因素5水平的正交试验,研究各因素对车辙因子的影响规律及程度,并使用灰色关联度法分析了基质沥青四组分比例、改性剂性能参数与70℃车辙因子的相关性。正交试验结果表明:改性沥青车辙因子受改性剂掺量的影响最大,其次是基质沥青,改性剂类型对车辙因子影响最小;灰色关联度分析结果显示:改性剂的伸长率、拉伸应力以及硬度与改性沥青的车辙因子有较好的相关性;基质沥青中芳香分和饱和分的含量与改性沥青车辙因子关联性较好。     

高等级公路沥青路面早期病害研究与防治

对高等级公路沥青路面的病害进行了研究,针对病害原因提出了高等级公路沥青路面病害防治措施和高等级公路沥青路面病害的具体处治方法,以避免和减少路面病害的发生。     

沥青混凝土路面抗车辙能力评价与车辙预防

分析了沥青混凝土路面的车辙成因及产生机理，并给出了几种沥青路面抗车辙能力的评价指标，介绍了用压实参数和间接拉伸强度联合评价沥青混合料的抗车辙性能的方法，提出了几种有效的车辙预防措施。     

高等级公路车辙产生的原因及处理措施

针对高等级公路一直存在车辙病害的现象,介绍了车辙的类型,重点分析了车辙产生的机理和原因,并提出了相应的处理措施,以提高高等级公路的路用性能,尽可能减少车辙的危害。     

浅析流动性车辙的影响因素

简单介绍了流动性车辙的概念、成因及其特征,并从内摩阻力、粘结力和外部因素三方面分析了影响沥青混凝土路面流动性车辙的因素,提出了采用蠕变试验评价沥青混合料高温稳定性的新方法,为路面设计提供了理论依据。