In order to study the effects of composite fiber on the performance of cold-mixed mixture of epoxy and SMA-10 asphalt,basalt fiber(BF)and polyester fiber(PF)codoping were carried out to analyze the effects of various composite fiber ratios on the high temperature performance,low temperature crack resistance,water stability,fatigue resistance,and aging resistance.A two-dimensional numerical model of asphalt mixture was constructed by digital image processing and discrete element simulation technol-ogy.The skeleton characteristic parameters of discrete element model were extracted to determine the optimal fiber blending length.The fiber contents were 0.3%PF,0.2%PF+0.1%BF,0.2%BF+0.1%PF,and 0.3%BF.The results show that the road per-formance,anti-fatigue performance and anti-aging performance of 0.3%basalt fiber are better than that of 0.3%polyester fiber.Among them,0.2%BF+0.1%PF has the best performance improvement.Compared with single-doped polyester fiber and basalt fiber,the dynamic stability of 0.2%BF+0.1%PF increases from 37 058 times·mm-1 and 42 000 times·mm-1 to 45 000 times·mm-1,an increase of 21.4%and 7.1%.The flexural tensile strength increases from 29.01 MPa and 30.53 MPa to 32.08 MPa,an increase of 10.6%and 5.1%.The fatigue life under 650 με strain condition increases from 1.63 million times and 1.83 million times to 1.97 million times,indicating a increase by 20.9%and 7.7%,respectively.The codoping of mixed fiber in the cold mix epoxy SMA-10 asphalt mixture can improve its road performance,and the mixed effect of basalt fiber and polyester fiber is better than that of single fiber.

The expansion of urban construction areas can reduce the infiltration rate of rainwater in permeable land, and a large amount of runoff rainwater cannot penetrate the soil. In extreme rainstorm weather, it is easy to cause serious urban waterlogging problems. To improve the infiltration and decontamination ability of green space soil, two types of inorganic ameliorants (i.e., sand and grain shell) and structural ameliorants (i.e., desulfurization gypsum and polyacrylamide) were utilized as amendments in the soil. The influence of the selected ameliorants on the infiltration and decontamination ability was analyzed through a soil infiltration test, soil pore distribution determination and a soil decontamination test. Three parameters including the soil infiltration rate, pore distribution characteristics and pollutant removal rate were proposed. The results showed that sand, grain shells and desulfurization gypsum (FGD gypsum) all enhanced the infiltration capacity of soil, while PAM decreased the infiltration capacity. Meanwhile, mixed sand and grain shell with the FGD gypsum and polyacrylamide can effectively improve the decontamination capacity of the soil. Comprehensive analysis showed that the better improvement combination is 10% sand + 20% grain hull + 0.5 g/kg FGD gypsum + 0.1 g/kg PAM.

为了对玄武岩纤维沥青混合料开裂性能进行预测研究,选用从不同老化程度的沥青玛蹄脂碎石混合料(SMA-13)中抽提的沥青样品的红外光谱参数,对混合料开裂性能参数进行预测分析.首先,选择美国州公路及运输协会(AASHTO)沥青混合料室内模拟老化手段,制备未老化、短期老化和长期老化SMA-13沥青混合料样品,并对其进行理想开裂测试(IDEAL-CT).分析总结了沥青混合料裂缝形成及扩展阶段的关键参数,即开裂形成功(Winitial)和开裂扩展指标(CTindex).然后,采用抽提试验对不同老化阶段的混合料样品中的沥青材料进行提取,并对其进行红外光谱分析.最后,采用灰色关联分析方法,选取了与Winitial和CTindex关联度最大的几种红外光谱参数,建立预测模型.试验结果表明:随着老化程度的加深,沥青混合料开裂性能逐渐降低.在未老化、短期老化、长期老化阶段,与未掺玄武岩纤维的混合料指标相比,玄武岩纤维沥青混合料的Winitial指标分别高9.4％、13.0％和16.6％.相对应的CTindex指标分别高69.8％、95.2％和116.2％.沥青材料的红外光谱参数可以用来对混合料的开裂性能进行预测.

为提出一种准确、高效的设计沥青混合料纤维掺量的方法,运用电子计算机断层扫描(CT)图像技术,提取不掺玄武岩纤维的沥青混合料的结构特征参数,确定3 mm、6 mm和9 mm这3种长度的AC-13级配玄武岩纤维的最佳掺配比例.按照不同比例设计5种组合的玄武岩纤维掺量,分别将其掺入此级配的沥青混合料中,进行相关的沥青混合料性能试验验证.研究结果表明:3 mm、6 mm和9 mm这3种长度的AC-13级配玄武岩纤维最佳掺配比例为2:5:2.与不掺玄武岩纤维相比,此比例搭配下的玄武岩纤维沥青混合料高温稳定性能、低温性能和抗开裂性能提高显著.动稳定度和贯入强度分别提高了21.1％和28.9％,低温性能提高了39.3％,CTindex指标和断裂能分别提高了147.56％和21.9％.

为了选择合适的测量和评估方案,更好地评估行车噪声在常规城市道路、装有隔音板道路、隧道和高架道路4种不同场景下的特性,获得行车噪声与行车场景的关联性,采用近场测试和远场测试两种方案收集和分析4种场景沥青路面行车噪声和交通场景之间的内在关联.结果表明:在远场试验中,常规道路上行驶噪声的总声压级随车速和路面温度变化明显,装有隔音板路面上行驶噪声的线性总声压级略高;在近场测试中,测试车行驶噪声A在4种场景下的整体声压级为:隧道路面>装有隔声板路面>常规路面>高架路面,且行驶噪声随车速增加的规律明显;噪声时域波形在近场测试中更加稳定,近场A加权1/3倍频程谱分析得到的A加权整体声压级与行驶速度和路面温度的相关性明显.

It is now more popular to use basalt fibers in the engineering programs to reinforce the crack resistance of asphalt mixtures. However, research concerning the impact of the basalt fiber diameter on the macro performance of AC-13 mixtures is very limited. Therefore, in this paper, basalt fibers with three diameters, including 7, 13 and 25 μm, were selected to research the influences of fiber diameter on the crack resistance of asphalt mixtures. Different types of crack tests, such as the low temperature trabecular bending test (LTTB), the indirect tensile asphalt cracking test (IDEAL-CT), and the semi-circular bend test (SCB), were conducted to reveal the crack resistance of AC-13 mixtures. The entire cracking process was recorded through the digital image correlation (DIC) technique, and the displacement cloud pictures, strain, average crack propagation rate (V) and fracture toughness (FT) indicators were used to evaluate the crack inhibition action of the fiber diameter on the mixture. The results showed that the incorporation of basalt fiber substantially improved the crack resistance, slowed down the increase of the displacement, and delayed the fracture time. Basalt fiber with a diameter of 7 μm presented the best enhancement capability on the crack resistance of the AC-13 mixture. The flexibility index (FI) of the SCB test showed a good correlation with V and FT values of DIC test results, respectively. These findings provide theoretical advice for the popularization and engineering application of basalt fibers in asphalt pavement.