抗车辙技术在油田公路中的应用

油田公路沥青路面在使用符合要求的A级沥青下,仍不能满足要求,在夏季高温条件下,沥青的粘度明显降低,使得沥青与矿料间的粘附性及混合料的抗剪强度下降,在交通车辆荷载的反复作用下,混合料发生永久变形形成车辙,结合在实际中的应有,为克拉玛依油田重载抗车辙沥青路面提供参考。     

沥青高温性能指标评价

对4种沥青（1种常规沥青和3种改性沥青）进行了25℃针入度、环球软化点、60℃粘度、高温下的标准动态剪切以及重复蠕变试验，对5个指标的试验结果特别是改性沥青重复蠕变试验结果进行了分析评价，最后由相应的沥青混合料车辙试验对上述指标进行了验证，验证结果表明，由重复蠕变试验结果得到的沥青蠕变劲度的粘性成分Ev与混合料车辙试验结果的排序一致。     

克拉玛依50号沥青路用性能研究

采用粘度、SHRP规范中车辙因子(G~*/sinδ)及混合料动稳定度评价50号和90号沥青的高温性能,采用SHRP规范中弯曲流变试验BBR的蠕变劲度及混合料低温开裂温度来评价沥青的低温性能。通过试验,50号沥青高温使用温度相对于90号沥青有大幅度提高,体现了50号沥青优良的抗车辙性能。     

沥青的零剪切粘度

在SHRP计划中,运用了多种仪器和方法来研究沥青材料的流变性能,如动态剪切流变仪、弯曲梁流变仪和直接拉仲试验仪等.研究中大量的数据表明对于直馏沥青来说,沥青胶结料的高温性能指标中G*/sinδ与沥青混合料的抗车辙性能的关联性较好,但是对于改性沥青和深度氧化沥青来说,沥青胶结料的G*/sinδ与混合料的抗车辙性能没有较好的对应关系,因此需要有另外一个技术指标来表征改性沥青混合料的抗永久变形能力.近几年来,研究发现沥青的零剪切粘度能够较好地表征沥青混合料的抗永久变形能力.本研究主要介绍几种常用的零剪切粘度测定方法和试验数据处理方法.     

聚酯纤维沥青混合料的试验及应用研究

聚酯纤维沥青混合料在江苏省已得到较大规模的应用。东南大学交通学院陈光伟博士通过掺加纤维和未掺加纤维的沥青混合料的水稳定性、高温稳定性、抗低温开裂等对比试验分析，研究了聚酯纤维沥青混合料的路用性能。对聚酯纤维沥青混合料作了简单经济分析。结合江苏省聚酯纤维沥青混合料的应用情况，提出了施工中的技术要点。研究表明，聚酯纤维沥青混合料具有良好的路用性能。聚酯纤维沥青混合料可作为江苏省解决沥青路面车辙问题和延长沥青路面使用寿命的技术选项。     

道路沥青混合料低温性能评价指标的研究

通过对七种沥青与不同矿料级配的沥青混合料劈裂抗拉试验、弯曲蠕变试验和劈裂蠕变试验，分析和研究沥青混合料的低温性能与路用性能关系，提出了沥青混合料低温关键性评价指标的界限值，经现场取样验证试验是可行的。     

抗扭转型高黏度改性沥青的研发与性能评价

排水沥青铺装的抗扭转飞散能力不足,从提升沥青胶结料性能的角度改善排水沥青混合料的抗扭转飞散能力。首先研究了影响排水沥青混合料抗扭转性能的关键胶结料技术指标,并结合日本相关公司标准,开发出了抗扭转型高黏度改性沥青。采用旋回式车辙试验、静扭试验和车辙试验评价了抗扭转型高黏度改性沥青的性能。研究表明,剪切应力是影响排水沥青混合料抗扭转性能的关键胶结料技术指标。采用开发的抗扭转型高黏改性沥青的排水沥青混合料的动稳定度是普通高黏度改性沥青混合料的2.5倍;变形量达到相同8 mm时需要约300 min,是普通高粘沥青混合料6倍。试验结果表明,抗扭转型高黏度改性沥青混合料具有很强的抗扭转飞散能力和高温稳定性。     

抗车辙沥青混合料组成设计方法探讨

以沥青路面车辙深度值、温度开裂数量、疲劳开裂面积等定量指标作为沥青混合料组成设计的直接控制指标，目前已成为沥青路面材料设计的发展方向，本文在传统沥青混合料设计方法—马歇尔设计法的基础上，结合道路的路面结构、交通、气候条件，建立了一种能定量控制沥青路面车辙深度，同时兼顾沥青路面抗裂、抗疲劳及耐久性的沥青混合料组成设计方法。     

影响沥青混凝土路面车辙因素分析

对沥青混合料出现车辙破坏的因素进行分析,研究了沥青混合料自身性能因素、环境因素,及不同沥青的混合料组合形式与车辙破坏的关系。并对沥青混合料二次加热重塑对车辙的影响进行研究。通过有限元法计算剪切应力随面层深度的变化关系。结果表明：沥青混合料抗车辙性能随空隙率、油石比、荷载和试验温度的增加而降低,采用高等级的沥青混合料组合可以降低车辙破坏。沥青混合料二次加热重塑会对沥青产生老化,使沥青混合料的动稳定度增大,降低了实验室对其抗车辙性能的预测和评估。计算结果表明,沥青路面在外界荷载作用时,中面层的剪应力通常最大,是最容易出现车辙的部位。     

就地热再生维修车辙技术的适用性分析

就地热再生维修车辙技术一般是对沥青路面表层3～5 cm厚的沥青混合料进行再生,而目前许多研究认为,中面层是产生车辙的主要层位。通过动态蠕变试验、车辙试验及有限元计算,从沥青路面中面层经过车辆荷载作用、自身材料的老化及就地热再生时中面层经过再压实后的抗车辙性能的变化三个方面分析了就地热再生维修车辙技术的适用性。研究结果表明：就地热再生维修车辙技术只对沥青路面表层进行处理,而不处理中、下面层的维修方法是可行的。     

滑板测粘方法在评价沥青低温性能方面的应用

采用力学模式比较清晰的自制低温滑板粘度计测定了沥青低温条件下的粘度值，验证了国家“八五”科技攻关课题“道路沥青及沥青混合料路用性能的研究”提出的沥青低温性能评价指标Ｐ．Ｉ和Ｔ１．２的有效性，同时在沥青和沥青混合料之间建立了更合理的联系．应用这一试验方法不仅可以评价沥青低温性能，更重要的是可由沥青低温特性预测沥青混合料的低温性能。     

沥青的酸值对沥青混合料水稳定性的影响

沥青与石料的粘附性好坏直接影响沥青混合料的耐久性。如果沥青选择不当且不掺外加剂，就很难得到稳定的沥青混合料。为此，探讨了不同性质的沥青对混合料水稳定性的影响，并提出了满足沥青混合料水稳定性指标的沥青酸值范围。酸性石料组成的混合料，必须对沥青进行改性处理后才能满足水稳定性要求。中性石料组成的混合料，当沥青酸值＞３．２ｍｇＫＯＨ／ｇ时，能满足抗水害要求；当沥青酸值＞３．５ｍｇＫＯＨ／ｇ时，混合料间接抗     

多孔性沥青混合料用结合料的性状与配制

根据国外经验，铺筑多孔性沥青路面需采用高粘度的改性沥青，文中论述了改性沥青的配制原理及其性能。     

THE EFFECT OF ASPHALT COMPOSITION ON THE FORMATION OF ASPHALTENES AND THEIR CONTRIBUTION TO ASPHALT VISCOSITY

Interactions among asphalt components have significant effects on the performance of asphalt binder. To understand those interactions, four asphalts, SHRP AAA-I, AAD-I, AAF-I, and AAG-I, were fractionated into three generic fractions according to Corbett's procedure and reblended into asphaltenes/aromatics/saturates ternary mixtures in various ratios. Mixtures were oxidatively aged with atmospheric air at temperatures of 87.7, 93.3, and 98.8°C for 5 to 33 days. The changes in chemical composition and physical properties were monitored using fourier transform infrared spectroscopy (FT-IR) and dynamic mechanical rheometry

The formation of asphaltenes is a major factor in the hardening of asphalt with aging. The data collected in this study indicate that the saturate content in the maltene phase has a profound impact on the contribution that asphaltenes have on the viscosity of aged asphalt. The data also suggest that the aromatics fraction is solely responsible for the formation of asphaltenes as an asphalt oxidizes.     

THE EFFECT OF ASPHALT COMPOSITION ON THE FORMATION OF ASPHALTENES AND THEIR CONTRIBUTION TO ASPHALT VISCOSITY

ABSTRACT

Interactions among asphalt components have significant effects on the performance of asphalt binder. To understand those interactions, four asphalts, SHRP AAA-I, AAD-I, AAF-I, and AAG-I, were fractionated into three generic fractions according to Corbett's procedure and reblended into asphaltenes/aromatics/saturates ternary mixtures in various ratios. Mixtures were oxidatively aged with atmospheric air at temperatures of 87.7, 93.3, and 98.8°C for 5 to 33 days. The changes in chemical composition and physical properties were monitored using fourier transform infrared spectroscopy (FT-IR) and dynamic mechanical rheometry

The formation of asphaltenes is a major factor in the hardening of asphalt with aging. The data collected in this study indicate that the saturate content in the maltene phase has a profound impact on the contribution that asphaltenes have on the viscosity of aged asphalt. The data also suggest that the aromatics fraction is solely responsible for the formation of asphaltenes as an asphalt oxidizes.     

躺滴法表征沥青的表面自由能

 表面自由能是用来确定沥青材料自身的黏聚功（黏聚强度）以及沥青与石料之间的黏附功的重要参数。此外,沥青混合料（包括沥青、石料和空气）的水敏感性也可使用沥青与石料的表面自由能参数进行评价。笔者采用躺滴法测定了几种战略公路研究计划(SHRP)沥青与液体的静态接触角,使用Owens-Wendt法确定了沥青的表面自由能。结果表明,躺滴法得到的沥青表面自由能与由接触角得到的数值比较接近,说明可以应用躺滴法来测定沥青的表面自由能。由沥青的表面自由能表征的沥青黏聚能结果与pull-off强度试验结果相吻合。     

木质素纤维在沥青混合料中的应用研究

通过对比试验，验证了木质系纤维对沥青材料的吸持能力，评价了木质素纤维对ＳＭＡ、ＯＧＦＣ沥青混合料强度、稳定性等性状的影响，表明木质表纤维对混合料流值影响明显，强度和稳定性略有改善，可以阻止沥青与沥青胶浆的排出，实现了新型、高性能沥青混合料实际应用的可达性。     

INTERACTION OF ASPHALT WITH GROUND TIRE RUBBER

This study characterizes the interaction of asphalt cement with ground tire rubber (GTR) using rheological tests, chemical characterization tests, settling and rubber dissolution tests. Curing time and temperature, mixing rate, rubber mesh size are important factors that affect the rubber depolymerization rate. The obtained high cure asphalt-rubber binders are homogeneous, compatible and have non-detrimental viscosity at hot-mix temperatures, while still being viscous and elastic at rutting temperatures and less stiff at cold temperatures than base asphalt.     

COMPOSITIONAL EVALUATION OF ASPHALT BINDER RECYCLING AGENTS

The results presented here indicate that it is possible to produce a high quality binder from hardened recycled asphalt by blending with recycling agents. The properties are presented in terms of Superpave grade and the hardening susceptibility (HS) which is defined as the slope of log viscosity versus infrared measured carbonyl area.

First it is shown that the effect of blending aged binder with aromatic agents is to decrease the HS in rough proportion to the amount of aromatic added and this is only slightly dependent on the aromatic source. The presence of saturates in the agent increases the HS. Using an AC-10 asphalt as the softening agent produced much higher HS values. Adding increasing amounts of aromatic agents on the other hand worsens the Superpave performance grade span. The addition of saturates to the agents has little effect on the span but shifts the span to lower temperature. Though increasing amounts of aromatic agents tended to decrease the grade span, in most instances the span was equal to that produced by blending the aged binder with the AC-10. The hardening susceptibility of the aromatic blends was better than that of the AC-10 blends and better even than the original asphalt.     

INTERACTION OF ASPHALT WITH GROUND TIRE RUBBER

ABSTRACT

This study characterizes the interaction of asphalt cement with ground tire rubber (GTR) using rheological tests, chemical characterization tests, settling and rubber dissolution tests. Curing time and temperature, mixing rate, rubber mesh size are important factors that affect the rubber depolymerization rate. The obtained high cure asphalt-rubber binders are homogeneous, compatible and have non-detrimental viscosity at hot-mix temperatures, while still being viscous and elastic at rutting temperatures and less stiff at cold temperatures than base asphalt.