掺TPS添加剂排水性沥青混合料的低温性能研究

对掺Tafpack Super(TPS)高黏度沥青添加剂排水性沥青混合料的低温脆化温度点,弯拉强度-应变包络图和三点弯曲蠕变速率进行了测试,同时与SBS改性沥青排水混合料的低温性能对比.结果表明,TPS对排水性沥青混合料的脆化点温度影响较小,但随着TPS掺量的增加,混合料在低温脆化点的抗弯拉强度显著增强;TPS能显著提高排水性沥青混合料的低温抗裂性能.随着TPS掺量的增加,0℃时三点弯曲蠕变速率有所增加.综合分析表明,掺加TPS高黏度沥青添加剂排水性沥青混合料的低温性能可以得到一定改善,但SBS改性沥青混合料仍具有最佳的低温抗裂性能.     

橡胶粉与TPS复合改性沥青及排水性沥青混合料性能研究

将废旧轮胎橡胶粉(CR)与TPS(Tafpack Super)改性剂进行复配,基于针入度评价体系、高黏改性沥青黏度、粘韧性评价体系和PG分级体系研究橡胶粉和TPS改性剂掺量对CR/TPS复合改性沥青高低温性能、流变特性和粘韧性能的影响,并分析了CR/TPS复合改性沥青混合料的路用性能。结果表明,CR/TPS复合改性沥青具有高黏、高弹、高软化点、优良的低温延展性和恢复性能;(16%～20%)CR+(8%～10%)TPS复合改性排水性沥青混合料比14%TPS改性排水性沥青混合料具有更好的水稳定性和低温抗裂性能。     

Duroflex~改性剂对沥青混合料性能影响研究

介绍了Duroflex改性剂的作用机理,分析了改性剂在不同掺量下对沥青粘度及沥青混合料水稳定性、高温稳定性、抗疲劳性能的影响,理论上得出Duroflex改性剂在混合料中的合理掺量为0.4%;对比试验分析了掺Du-roflex改性剂沥青混合料与SBS改性沥青混合料的性能,结果表明AC-25C型混合料中掺0.3%的Duroflex改性剂与SBS改性沥青混合料的水稳定性相当,但SBS改性沥青的高温稳定性具有一定优势。     

有机蛭石与纳米二氧化钛复配改性沥青的抗老化性能研究

研究了有机蛭石与纳米TiO2复配改性剂对沥青物理性能和流变性能的影响,并分析不同老化方式下复配改性剂对沥青抗老化性能的改善效果。结果表明,复配改性剂对沥青的物理性能和流变性能影响较小。复配改性剂的加入可以达到同时改善沥青耐热氧和紫外光老化性能的目的,但是改善效果受复配掺量的影响较大,不同掺量的复配改性剂对沥青的短期和长期热氧老化性能都有改善效果,而耐紫外光老化性能的改善只在特定的复配改性剂掺量下才能体现。综合热氧老化和紫外光老化性能数据,复配改性剂的最佳掺量为1%的有机蛭石和3%的纳米TiO2。     

LDHs/SBS改性沥青混合料性能的研究

采用不同LDHs改性剂掺量的LDHs/SBS改性沥青制备LDHs/SBS沥青混合料,通过一系列试验,研究了LDHs改性剂不同掺量对LDHs/SBS沥青混合料性能的影响。研究结果表明:沥青混合料的稳定性随LDHs掺量增加而提高并且体积性能指标不变;LDHs的加入能改善沥青混合料的水稳定性,但加入量超过5%时改善能力减弱;随着LDHs掺量的增加,沥青混合料的高温抗车辙性能提高。     

SBR胶乳高旧料热再生沥青混合料性能研究

为了能够制备高性能高RAP料掺量(高达50%)的厂拌热再生沥青混合料,本文基于改性再生的理念,研究了SBR胶乳作为改性剂对于含有再生剂的老化沥青以及50%RAP料掺量的热再生沥青混合料的性能的影响,并与再生剂的作用效果进行了对比分析。室内性能试验结果表明,再生剂的软化效应对再生混合料的高温性能不利。在含有再生剂50%RAP料掺量的再生沥青混合料中加入SBR胶乳能够明显改善再生沥青混合料的高温性能,弥补再生剂的不足,同时SBR胶乳能够提升再生混合料的低温抗裂性能和抗水损害性能,使其达到或者超过全新沥青混合料的水平。     

沥青类与改性剂用量对高粘度改性沥青性能的影响

采用TPS为改性剂制备高粘度改性沥青,研究了TPS对不同基质沥青的改性效果及TPS掺量对改性沥青性能的影响。结果表明:TPS对沥青的改性效果与基质沥青的组成密切相关,在相同TPS掺量下,基质沥青的胶质含量越大,改性沥青的60℃粘度越大;在TPS掺量为14%~17%之间,TPS掺量对改性沥青的软化点、针入度和延度的影响较小,而对60℃粘度影响显著,对于S-70沥青,在TPS掺量大于15%以后,其60℃粘度迅速增大。     

排水性沥青路面OGFC-13配合比设计

介绍了OGFC路面的性能特点,从原材料选择阐述了OGFC混合料对集料、沥青等原材料的技术要求、试验方法以及OGFC混合料配合比设计的主要步骤,通过对掺加TPS改性剂的排水路面沥青混合料配合比分析与性能测试,为西安咸阳国际机场专用高速公路排水路面施工应用提供技术依据。     

改性植物沥青及其混合料路用性能

为了降低沥青混合料中石油沥青的使用量,研究提出采用植物沥青作为改性剂制备改性植物沥青.通过对改性植物沥青老化前后3大指标试验、DSR试验以及BBR试验结果分析,确定改性植物沥青的最佳掺量,并对比分析改性前后沥青混合料的路用性能.结果表明:与普通SBS改性沥青相比,改性植物沥青的低温抗裂性和抗疲劳性能有所提升,而高温性能有所下降;当植物沥青掺量为12%(质量分数)时得到的改性植物沥青综合性能较优;改性植物沥青混合料的稳定度、动稳定度、残留稳定度、残留强度比及低温弯曲应变分别是普通SBS改性沥青混合料的0.88,0.94,1.08,1.11和1.15倍.     

添加不同改性剂的沥青混合料低温性能试验

针对沥青混合料的低温问题,选取约束试件温度应力试验和TPS,湖沥青及Sasobit三种改性剂进行了沥青混合料的低温性能试验,通过试验结果可知,TPS对低温性能的改善最好,其次是Sasobit,湖沥青最差。     

Laboratory evaluation of the effects of short-term oven aging on asphalt binders in asphalt mixtures using HP-GPC

Both the RTFO (rolling-thin film oven) aging of asphalt binders and the STOA (short-term oven aging) of asphalt mixtures are designed to simulate aging during the construction of hot mix asphalt (HMA) pavements. Many studies have been conducted evaluating the aging effects on asphalt binders since their properties can be easily measured using many conventional tests, such as rotational viscometer, DSR (dynamic shear rheometer), and BBR (bending beam rheometer). However, studies on asphalt mixture aging have been limited to mechanical properties such as strength and fatigue characteristics because considerable effort is required to identify the aging of the asphalt binder in a mixture. This study evaluated the effects of short-term oven aging on asphalt mixtures using the GPC (gel-permeation chromatography) procedure. Nine asphalt mixtures, using three different binder sources, were prepared and five short-term aging methods were used to evaluate these mixes. For comparison, the RTFO aging was also conducted for nine asphalt binders. The aging of a binder within asphalt mixtures, including polymer-modified mixtures, could be identified under various short-term aging conditions. Statistical analysis of the GPC test results indicated that two commonly used short-term aging methods in the laboratory, a 154 °C oven aging for 2 h and a 135 °C oven aging for 4 h, are not significantly different, based on the increase in the large molecular size (LMS) ratios. The RTFO aging method was found to have less effect on binder aging than the short-term oven aging methods of asphalt mixtures.     

TPS高粘度改性沥青在OGFC路面中的应用研究

介绍了排水性沥青混合料结合料的发展与现状,对TPS改性沥青的性能作了评价,就TPS在降噪排水路面中的应用进行了研究,研究表明,使用TPS高粘度改性沥青可以很好地满足OGFC排水性沥青路面的路用性能要求。     

SBS，SBR改性沥青抗紫外线老化性能对比

对低温性能较好的SBS,SBR这2种改性沥青在薄膜烘箱老化试验(thin film oven test,TFOT)以及经不同时长紫外线老化后的性能进行了室内试验分析对比.结果表明,SBR改性沥青原样及经薄膜烘箱老化后,其低温延展性能明显优于SBS改性沥青,但在接受一定时间的紫外线照射后,SBR改性沥青的低温延度发生骤减,相同温度下其延度不及SBS改性沥青,说明SBS改性沥青的抗紫外线老化性能比SBR改性沥青好,这为高寒、高海拔地区沥青路面改性剂的选择提供了新的参考.     

Aging analysis of rubberized asphalt binders and mixes using gel permeation chromatography

This study was initiated to investigate the aging characteristics of binders due to the reaction with the crumb rubber. For this laboratory study, the crumb rubber modified (CRM) and control binders were aged using an oven aging method. Also, asphalt mixtures with CRM or control binders were made and subjected to short-term and long-term aging treatments. The properties of these aged binders were evaluated using gel permeation chromatography (GPC) test procedures. The results from this study showed that: (1) the higher CRM percentage resulted in the higher large molecular size (LMS) value of asphalt binder under the binder aging conditions, and the rate of increase in the LMS value was found to have a relation to the CRM percentage. The asphalt binders with higher CRM percentages (15% and 20%) had a trend the LMS values decrease after a certain level. This finding is thought to be related to the required time for the rubber to be fully digested; (2) after subjecting to the long-term oven aging, the asphalt mixtures with the control and CRM modified binders were found to have statistically insignificant differences in aging level, measured using the LMS values. The very thin film thickness of binder in asphalt mixture and the aging temperature of 100 °C insufficient to enable a reaction were considered to be the main reasons that no differences were observed from the standpoint of the aging effect.     

高黏沥青改性剂在贵州省干线公路养护工程中的应用

以自主研发的高黏沥青改性剂PEA为研究对象,以日本进口改性剂和某国产品牌改性剂作为平行对比,分别对高黏沥青和高黏沥青混合料的性能进行分析,并铺筑排水沥青路面试验段。结果表明,掺加高黏沥青改性剂PEA制备的混合料路用性能和施工性能优良,具有较好的耐老化性。路面经现场检测,各项技术性能符合《排水沥青路面设计与施工技术细则》(征求意见稿)要求。     

废机油残留物再生沥青的抗老化性能

以废机油残留物(REOB)作为沥青再生剂,从REOB自身、REOB再生沥青及REOB再生沥青混合料3个层次进行老化性能研究.通过延时薄膜烘箱老化试验(TFOT)(老化时间分别为5、10、15、20、25 h),测定了REOB再生沥青、RA5再生沥青和基质沥青的质量及黏度变化,并采用弯曲梁流变试验评定3种沥青老化后的低温...     

热氧老化沥青多次损伤-愈合性能

为研究沥青在多次损伤条件下的愈合性能,采用动态剪切流变(DSR)仪中的时间扫描模式对沥青进行损伤-愈合循环加载试验,以沥青愈合期间的复数模量恢复程度(即愈合指数)为愈合指标,分析了不同热氧老化程度下70~#基质沥青与SBS改性沥青多次损伤-愈合性能规律,并结合沥青傅里叶红外光谱(FTIR)试验,以特征官能团峰面积比定量分析了沥青功能基团的组成和含量对其自愈能力的影响.结果表明:沥青愈合指数随损伤-愈合次数的增加而减小,首次损伤时沥青愈合指数减小程度最大.老化程度对沥青愈合指数影响显著,表现为老化程度越高愈合指数越小.SBS改性沥青多次损伤-愈合和老化后的愈合性能均优于70~#基质沥青,SBS改性剂可增强沥青的抗疲劳损伤能力和抗老化能力.沥青中大分子含量越高,分子扩散速率越慢,自愈能力越弱;轻长型分子含量越高,分子扩散速率越快,自愈能力越强.     

Laboratory evaluation of flexible pavement materials containing waste polyethylene (WPE) film

This paper presents a research to recycle the waste vinyl (waste polyethylene film: WPE film) in asphalt mixtures for improving the performance properties of the mixtures. Conventional Marshall mix designs were carried out with varying WPE contents, and the best performing content of WPE film was determined from the previous study. Also, asphalt mixtures with two commercial polymer modifiers, low-density polyethylene (LDPE) and a styrene–butadiene–styrene (SBS), were used to compare the effectiveness of WPE-modified mixture. The strength characteristics such as Marshall stability and indirect tensile strength (ITS) were evaluated, and the wheel tracking test, result of which is generally considered to reflect the field performance, was conducted to measure the rutting resistance of the asphalt mixtures. From the results of this study, asphalt mixture with waste vinyl showed much better rutting resistance than normal asphalt mixture without WPE. It is hypothesized if an optimum content of waste vinyl is used, it is expected that the waste vinyl will be effective as much as commercial modifier in improving the performance of asphalt pavements.     

Effects of aging on the properties of modified asphalt binder with flame retardants

Effects of aging on the properties of asphalt binders modified by incorporating Styrene–Butadiene–Styrene (SBS) and flame retardants (FR) were studied. Asphalt binders were artificially aged in the rolling thin film oven (RTFOT) and Pressure Aging Vessel (PAV). The flame retardancy of modified asphalt binders were characterized using limited oxygen index (LOI), and the effects of aging on the properties of asphalt binders were studied using Brookfield viscometer test and dynamic shear rheometer test. Experimental results indicated that the flame retardancy of asphalt binder was increased after aging. But the increasing amount of LOI is low when the modified asphalt binder containing more flame retardants. The variation of the LOI, softening point, penetration, ductility and viscosity of asphalt binder decreased with flame retardant content increasing, meaning the flame retardants can improve the thermo-oxidative aging resistance of asphalt binder. Furthermore, the G^*/sin δ, stiffness and m-value of flame retardant modified asphalt binders display smaller changes after two different aging.