An Accelerated Method for Determining Asphalt Oxidation Kinetics Parameters for Use in Pavement Oxidation and Performance Modeling

A new and innovative strategy has been developed for using the pressure aging vessel (PAV) at 90°C and 100°C and elevated pressure (2.1 MPa) for predicting asphalt oxidative embrittlement and its consequent loss of durability over years of pavement service. At elevated pressure and temperature, the method requires significantly less time, days not months, to determine atmospheric oxidation kinetics parameters than tests at 1 atm. Nevertheless, it allows fundamentals-based durability predictions specific to each material and pavement climate. One atmosphere kinetics parameters predicted from PAV data using a new correlation, together with a pavement oxidation and performance model, form the new performance prediction strategy.     

Oxidation Hardening Kinetics of the Rheological Function G′/(η′/G′) in Asphalts

Abstract

The authors used 9 asphalts oxidized at various temperatures and pressures to determine the hardening kinetics for the DSR function, an easily measured and meaningful surrogate for 15°C ductility that relates well to age-related binder deterioration. For each asphalt, there is a rapid initial period that slows to a constant rate period. This constant rate period can be represented by carbonyl formation (oxidation) rate times a hardening susceptibility (HS). For the DSR function and viscosity, the HS and initial jump were pressure- but not temperature-dependent. The DSR function initial jump was relatively higher than the viscosity initial jump.     

阻燃环保沥青的开发及性能评价

通过向SBS改性沥青中添加无机阻燃剂的方法开发了阻燃环保沥青,并对SBS改性沥青和阻燃环保沥青进行了胶结料和混合料的性能试验。结果表明：阻燃环保沥青的常规性能与SBS改性沥青相比变化不大,而氧指数得到了较大的提高,较好地改进了阻燃性能。对SBS改性沥青及阻燃环保沥青混合料进行了车辙试验、小梁弯曲试验、水稳定性试验等,结果表明：阻燃环保沥青混合料的路用性能与SBS改性沥青相当。同时,模拟燃烧结果表明,阻燃环保沥青有效改善了沥青混凝土的阻燃性能。     

(阿尔巴尼亚)塞拉内兹湖天然沥青改性加德士沥青的路用性能评价

采用湿法工艺,以阿尔巴尼亚塞拉内兹湖天然沥青为改性剂对加德士70号沥青进行了改性,分析了改性沥青的性质;以改性沥青为胶结料,进行了AC-13型混合料的拌制、检测。结果表明,与基质沥青相比,改性沥青针入度降低、软化点升高、表观黏度增大、高温等级提高而低温性能基本不变;动稳定度提高,车辙深度降低,冻融劈裂强度比增强,高温稳定性和水稳定性提高。     

C-50彩铺胶结料的研制

介绍了低针入度硬质彩铺胶结料的研制过程。结果表明彩铺胶结料具有良好的高温性能、水稳定性和低温性能,适合于重载交通路面建设的需要。     

沥青结合料高温指标浅析

沥青结合料的高温性能密切关系到沥青路面性能的优劣。以沥青常规试验为基础得到老化前后的沥青常规指标：25℃针入度、软化点、60℃动力粘度及当量软化点,以沥青混合料车辙实验验证用这四种指标评价沥青高温性能是否可靠。发现老化前沥青的60℃动力粘度与动稳定度排序较一致。相关系数为0.756;老化后沥青的60℃动力粘度及当量软化点与动稳定度排序完全一致。相关系数分别为O.741、0.959。研究认为RTFOT沥青的当量软化点可以更准确地反映沥青的高温性能。     

湿度对PAV老化后沥青胶结料流变性能的影响

For the most coastal areas where the air is very humid, study on the effect of humidity on the performance of asphalt has its practical signiifcance. However, limited research has been done to investig...     

紫外线作用下道路沥青老化行为研究

为了研究紫外线老化下沥青性能变化,选取同种产地、不同标号的两种基质沥青以及两种常规改性沥青,分析基质沥青在不同紫外线老化后组分变化,研究四种沥青在不同时长紫外绒老化后的三大指标、DSR和BBR试验。结果表明,选用沥青老化后C/H值来评价同种来源基质沥青紫外老化性能是可行的,并可以通过使用DSR、BBR补充评价基质沥青和改性沥青紫外线老化后的高低温流变性能。     

APA评价再生沥青混合料路用性能

利用沥青路面分析仪(APA)，通过与新鲜沥青混合料的对比，评价两种不同级配的再生沥青混合料高温稳定性、抗疲劳性能、抗水损害性能和长期路用性能。试验结果表明小掺量下的再生沥青混合料可以到达与新鲜沥青混合料相同的路用性能。     

湖沥青改性AC-25C沥青混合料在涪南高速的应用研究

为探索重庆地区高速公路使用效果更好的新路面结构,结合重庆涪南高速沥青路面工程,进行了湖沥青改性沥青混合料在重庆地区高速公路路面工程下面层的应用研究。研究中为降低湖沥青改性沥青加工难度和确保湖沥青下面层的工程质量,取消软化点评价指标,以弥补湖沥青改性混合料高温稳定性差、抗车辙能力弱等缺点。通过改进的湖沥青复合改性方案对25%掺量的特立尼达湖沥青改性AC-25C沥青混合料进行了配合比设计及路用性能研究,并与常规沥青路面性能进行对比,同时进行试验路验证,为重庆地区湖沥青改性应用于路面工程提供了技术支持。     

RTFOT与TFOT对沥青胶结料热老化程度的影响

通过分析老化沥青残留物的质量变化，针久度，粘度，车辙因子和低温蠕变性能，比较RTFOT和TFOT条件下沥青胶结料热老化程度的差异，结果表明：TFOT残留物在常温和高温下的粘度及车辙因子平均水平均低于RTFOT残留物，但低温性能呈现出不同的行为，影响程序取决于沥青品种，当对沥青进行PG分级时，若沥青性能指标接近临界值时，不能忽 视两种老化条件引起的差异，否则容易出现误判。     

沥青老化机理分析

利用红外光谱测试手段,探讨了韩国SK AH-70沥青和SBS沥青在热老化作用下发生的化学组成变化情况;碳氧双键、硫氧双键、氮氧双键含量的增加是沥青老化的重要标志,如果能够通过某种物理或化学手段来减小他们的含量,尤其是能够找到一种廉价易得的试剂来打破这些双键,可能是一种比较有效的沥青再生的方法。     

Aging Behavior of Colored Paving Asphalt

In this paper, the aging processes of colored paving asphalt conforming to GB/15180-94 standard were studied by rotate thin film oven (RTFO) test. The results show that the established two dynamics models can be use to describe the aging velocity of the two kinds of colored paving asphalt perfectly. After aging, asphaltene content increased, resins and aromatics content, as well as saturate content decreased. As a result, the original colloidal structure of colored paving asphalt is destroyed, which deteriorates performance of the colored paving asphalt. During aging, the Gastel index (Ic), which is sensitive to aging conditions, decreased with increase of aging temperature and extension of aging time. Therefore, the Gastel index can be used to evaluate the aging resistance of the colored paving asphalt.     

抗车辙剂沥青混合料路用性能试验研究

采用A级70号、A级70号+抗车辙剂及SBS改性沥青作为胶结料拌制沥青混合料,分别对三种沥青混合料的高温稳定性、抗水损害能力及低温抗裂性能等路用性能进行了室内试验研究。试验结果表明掺加抗车辙剂的沥青混合料高温稳定性得到很大程度的提高,抗水损害能力没有显著变化,低温抗裂性略有降低。     

泡沫沥青冷再生的试验研究

通过对泡沫沥青混合料的配合比设计,探讨了泡沫沥青冷再生混合料的性能特点,并对设计材料的有关性能进行了分析,以期对泡沫沥青的应用具有借鉴意义。     

温拌沥青混合料降温效果及路用性能对比研究

降低沥青混合料拌和和压实温度具有重要的经济和社会效益。通过对掺加温拌剂FH-3沥青混合料降温效果和路用性能试验与基质沥青混合料对比研究,结果显示:拌和和压实温度分别能够降低18.1℃和15℃,能够起到降温效果的目的,同时所测试路用性能都符合规范要求,且低温、水稳和抗疲劳性能提高。     

沥青混合料自然老化历程中抗剪强度演变规律研究

为了解沥青混合料在自然老化历程中抗剪强度的演变规律,采用单轴贯入试验与单轴压缩试验对不同自然老化时间后的沥青混合料,在干燥和冻融循环后饱水两种情况下进行试验。试验结果表明：老化过程中沥青混合料的抗剪强度逐渐下降。在饱水状态下比在干燥状态下有更强的抵抗荷载作用的能力;随着老化程度的增加,冻融循环抗剪强度比有上升的趋势;另外水对自然老化后的沥青混合料的进一步侵蚀作用不明显。     

Aging Performance of SBS Modified Asphalt

Abstract

The penetration, softening point, and ductility of the aging basic asphalt and styrene-butadiene-styrene (SBS) modified asphalt were studied, and the thin film oven aging behavior of them was researched by using infrared spectrum. The experimental results showed that the softening point was increased, the penetration and ductility were decreased after basic asphalt thin film oven aging; the results of aging SBS modified asphalt thin film oven aging was similar too. The research of infrared spectrum indicated that absorbing–oxygen oxidation reaction was taking place when basic asphalt film was aging, carbonyl and sulfoxide groups were increased after SBS modified asphalt thin film oven had been aging. The aging extent of SBS modified asphalt was bigger than basic asphalt and the ability of bearing low temperature was better. SBS modified asphalt could have worse anti-aging performances than that of base asphalt.     

沥青老化机理综述

在查阅国内外相关资料的基础上,综述了沥青老化的主要机理。认为,沥青的化学组分变化是导致沥青＂变硬＂的外因,然而轻质组分的挥发和被吸收、各组分的氧化、聚合、沥青质的团聚以及改性剂的裂解才是导致组分变化和沥青老化的真正内因。     

中石化抗车辙沥青母粒性能研究

硬质沥青良好的高温性能,能够用于解决路面严重的早期车辙病害,因此最近几年硬质沥青或高模量沥青混合料成为公路界及材料界研究者的关注热点。通过对中国石化抗车辙沥青母粒新产品性能的分析研究,证明其具有便捷的使用方式,良好的路用性能,能够适应路面材料的发展趋势。