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1.
基于疲劳性能的应力吸收层混合料设计指标   总被引:1,自引:0,他引:1  
以基质沥青与胶粉搅拌制备橡胶沥青,以基质沥青与SBS改性剂搅拌制备SBS改性沥青,然后分别采用相应的级配设计橡胶沥青应力吸收层混合料和SBS改性沥青应力吸收层混合料.选取目前常见的Strata应力吸收层混合料为对比材料,通过大量四点弯曲小梁疲劳试验(15℃)对这3种改性沥青混合料进行1500×10-6应变下的疲劳试验,分析混合料疲劳寿命与胶粉掺量(质量分数)、SBS改性剂掺量(质量分数)及改性沥青针入度、软化点、黏度的关系.结果表明:Strata应力吸收层混合料在1500×10-6应变下的疲劳寿命为302023次,因此以1500×10-6应变下疲劳寿命≥3×106次作为应力吸收层混合料的设计指标.橡胶沥青应力吸收层混合料疲劳寿命与胶粉掺量和橡胶沥青177℃黏度具有很好的相关性,按设计指标进行橡胶沥青应力吸收层混合料设计时,要求胶粉掺量为19.6%~20.5%,橡胶沥青177℃黏度维持在3.4~3.6Pa·s.SBS改性沥青应力吸收层混合料疲劳寿命与SBS改性剂掺量和SBS改性沥青针入度、软化点、135℃黏度具有很好的线性相关性,按设计指标进行SBS改性沥青应力吸收层混合料设计时,若A型、B型SBS改性剂混合使用,则要求SBS改性剂掺量≥6.5%,SBS改性沥青针入度≤5.1mm,SBS改性沥青软化点≥93℃,SBS改性沥青135℃黏度≥1.95Pa·s;适当加大油石比和调整级配中关键筛孔通过率可增大SBS改性沥青应力吸收层混合料疲劳寿命;B型SBS改性剂更适合用在SBS改性沥青应力吸收层混合料设计中.  相似文献   

2.
黄卫东  郑茂  黄明 《建筑材料学报》2015,18(6):1089-1094
在对应的设计空隙率下,进行考虑自愈合作用的多种沥青混合料疲劳性能的对比研究.采用Nf50法判断基质沥青混合料疲劳寿命,采用NfNM法判断改性沥青混合料疲劳寿命.结果表明:当未考虑自愈合作用时,AC-13terminal blend(TB)胶粉+SBS改性沥青混合料具有最好的疲劳寿命,随后依次为ARAC-13橡胶沥青混合料、AC-13SBS改性沥青混合料和AC-13TB胶粉+岩沥青改性沥青混合料等;当考虑自愈合作用后,ARAC-13橡胶沥青混合料具有最好的疲劳寿命,随后依次为AC-13TB胶粉+SBS改性沥青混合料、AC-13SBS改性沥青混合料和AC-13TB胶粉+岩沥青改性沥青混合料等.TB胶粉改性沥青混合料及其各类复合改性沥青混合料具有极大的科研和应用价值.  相似文献   

3.
沥青已被证实具有自愈合特性,并且该特性可以延长沥青混合料的疲劳寿命。为了研究沥青与混合料的自愈合特性,选用基质沥青和SBS改性沥青借助于DSR时间扫描实验以及四点弯曲疲劳试验,分别研究了沥青与混合料的自愈合特性。实验结果表明:SBS改性沥青的自愈合特性优于基质沥青,并且这种自愈合优势随着损伤程度的增加而逐渐降低。SBS改性与基质沥青的自愈合能力均随损伤度增加而减小,并且其减小速率在较低损伤度时更为明显。SBS改性沥青混合料的自愈合性能优于基质沥青混合料,说明了沥青与混合料的自愈合性能具有一致性。  相似文献   

4.
为探讨玄武岩纤维和高模量改性剂在提高沥青混合料抗疲劳性能方面的适用性,选取AC-20C级配,对比分析了基质沥青混合料、SBS改性沥青混合料、玄武岩纤维沥青混合料、高模量沥青混合料以及玄武岩纤维高模量沥青混合料在不同应变水平下的疲劳寿命次数。结果表明:玄武岩纤维和高模量改性剂对沥青混合料的疲劳性能改善明显。  相似文献   

5.
使用四点弯曲疲劳试验(4PB)、两点梯形梁疲劳试验(2PB)和overlay tester(OT)试验3种试验方法,对工程上常用的7种沥青混合料疲劳性能进行了测试.结果表明:在3种疲劳试验中,掺加6%(质量分数,下同)SBS的改性沥青混合料疲劳性能均较好,同时掺加10%TB胶粉和3%SBS的改性沥青混合料、掺加4.5%SBS的改性沥青混合料和同时掺加4.5%SBS及0.4%多聚磷酸(PPA)的改性沥青混合料疲劳性能均一般,掺加3%SBS的改性沥青混合料疲劳性能较差,温拌剂改性沥青混合料和埃索基质沥青混合料的疲劳性能最差;提高SBS掺量可以有效地提高沥青混合料的疲劳性能;添加TB胶粉和PPA可以在不同程度上提高SBS改性沥青混合料的疲劳寿命,但其对疲劳性能的影响力逊于SBS;不同试验方法中沥青混合料疲劳性能的排序具有一致性,具体排序稍有不同.  相似文献   

6.
基于改进后的车辙试验、低温弯曲试验、低温预切口SCB试验、四点弯曲疲劳试验,研究了布顿岩沥青(BRA)复合木质素纤维、聚酯纤维、玄武岩纤维改性沥青混合料的路用性能和耐久性。结果表明,BRA改性沥青混合料具有优良的高温性能和抗疲劳耐久性能;掺加木质素纤维、聚酯纤维和玄武岩纤维均可一定程度提高BRA改性沥青混合料的弯拉强度,显著增加弯拉应变和破坏应变能,BRA复配纤维改性沥青混合料具有优良的低温抗裂性能;掺加纤维可显著延长BRA改性混合料的疲劳寿命,同时降低了BRA改性沥青混合料的疲劳性能对应变水平的敏感性,聚酯纤维对BRA改性沥青混合料低温性能改善效果最佳,玄武岩纤维对BRA改性沥青混合料高温性能和疲劳性能改善效果最佳。  相似文献   

7.
采用重复蠕变恢复试验分析了多聚磷酸对基质沥青、SBS及SBR改性沥青抗变形恢复能力的影响,并通过贯入剪切试验、半圆弯拉试验及弯曲疲劳试验评价了多聚磷酸对基质沥青混合料、SBS改性沥青混合料及SBR改性沥青混合料抗剪切性能、低温抗裂性能及疲劳性能的影响,采用Weibull分布分析了不同沥青混合料在不同失效概率下的疲劳性能.结果表明:多聚磷酸的掺入显著增加了沥青的黏度,对其弹性变形恢复能力贡献较小,而SBS改性剂可大幅度提高沥青的弹性变形恢复能力;多聚磷酸能够明显改善沥青混合料的高温抗剪稳定性;通过复配SBS或SBR改性剂,可有效弥补多聚磷酸对沥青混合料低温性能的负面影响;多聚磷酸对沥青混合料的疲劳性能也有一定程度的改善.  相似文献   

8.
为研究离子型聚合物乙烯-甲基丙烯酸甲酯(EMAA)和SBS对沥青及沥青混合料路用性能、自愈性能的影响,分别通过动态剪切流变(DSR)试验和弯曲梁流变(BBR)试验对EMAA/SBS复合改性沥青及沥青混合料的路用性能进行评价,采用自愈合延度试验和DSR疲劳-愈合-再疲劳试验研究复合改性沥青及沥青混合料的自愈性能.结果表明:相比于基质沥青、SBS改性沥青及其混合料,复合改性沥青及其混合料的高温稳定性、耐久性及自愈性能有了显著提升;复合改性沥青及其混合料的低温性能较之SBS改性沥青及其混合料有所降低,但仍满足规范中改性沥青的要求.  相似文献   

9.
商华有 《市政技术》2019,(1):209-212
为保证沥青混合料的抗疲劳性能,采用3点弯曲疲劳试验研究了应力比、加载频率和沥青种类对沥青混合料疲劳寿命的影响规律。研究发现,不同结构类型的沥青混合料疲劳寿命随应力比增加而逐渐减小,相同应力比下,SMA-13的疲劳寿命至少是AC-13的1.4倍;沥青混合料的疲劳寿命随加载频率的增加而逐渐增加,同一加载频率下沥青混合料疲劳寿命减小幅度随应力比的增加不断降低;SBS改性沥青抗疲劳性能优于克拉玛依70号沥青,对改善沥青路面耐久性能作用明显。  相似文献   

10.
为研究不同乳化沥青掺量下水泥稳定碎石混合料的疲劳性能,对室内静压成型的中梁试件进行了四点弯拉疲劳试验,并基于Weibull分布建立了乳化沥青水泥稳定碎石混合料的疲劳寿命预估模型.结果表明:掺入乳化沥青后,水泥稳定碎石混合料的弯拉强度略微降低,但弯拉变形和弯拉应变功显著增大;混合料的疲劳寿命在低应力水平下明显提高,在高应力水平下近似不变,乳化沥青的掺入有效提高了水泥稳定碎石混合料的疲劳性能.  相似文献   

11.
柔性基层沥青路面结构黏弹性力学响应分析   总被引:5,自引:0,他引:5  
沥青混合料是典型的黏弹性材料,只有对沥青路面结构进行黏弹性分析,才能得到其实际的力学响应。对一柔性基层沥青路面的各层沥青混合料进行了不同温度、不同频率下的复数模量试验,并利用黏弹性理论关系式,将沥青混合料复数模量试验结果转化为其蠕变柔量的Prony系列表达式,并进而求解在静载和加载、卸载两种荷载模式下路面结构路表弯沉、基层底面拉应变和土基顶面压应变的黏弹性力学响应。研究结果表明,由于沥青混合料的蠕变和松弛特性,各种响应尤其是基层底面的拉应变随时间呈现出较为复杂的变化趋势。随加载或卸载时间的延长,各响应逐渐趋于稳定。本研究也表明进行黏弹性分析可以更科学地描述沥青路面结构的行为特性及破坏原理。  相似文献   

12.
Fatigue crack is a main form of structural damage in flexible pavements. Under the action of repeated vehicular loading, deterioration of the asphalt concrete materials in pavements caused by the accumulation and growth of the micro and macro cracks gradually takes place. The indirect tensile tests was carried out on hot mix asphalt HMA and stone matrix asphalt SMA mixtures comprising different nominal maximum aggregate sizes NMAS in three temperatures of 5, 25 and 40 °C. Stiffness modulus, fatigue lives and fatigue prediction equation of the mixtures were developed and characterized in terms of aggregate gradation type, coarseness and fineness of gradation, temperature and asphalt content.  相似文献   

13.
This paper describes the results of laboratory and full scale performance tests for a high modulus asphalt binder (HMAB) and mixes (HMAM) developed in this study for long life asphalt pavements. Various binder tests were first conducted on the HMAB and test results showed that the stiffness of the HMAB was significantly increased compared to the conventional binder without changing the low temperature properties of the binder. Laboratory tests for the mixes included dynamic modulus, moisture susceptibility, wheel tracking and fatigue tests.Dynamic modulus test results showed that the modulus of the HMAM was 50% higher than those of the conventional mix at the high temperatures. The results of performance test indicated that the resistances of the HMAM against moisture, rutting, and fatigue damage were better than those of the conventional mix. It was also found from the full scale test sections that the tensile strain values at the bottom of the asphalt layer for the HMAM sections were lower than those of the conventional mix sections although the asphalt layer thicknesses of the HMAM sections were thinner than those of the conventional sections. All the tensile strain values measured from the HMAM sections were within the fatigue endurance limit of 70 microstrain which is the fatigue criterion of a long life asphalt pavement. Similar to the wheel tracking test results, the rut depth occurred in the thick HMAM test section was two times smaller than the conventional pavement section.  相似文献   

14.
This paper presents the results of a laboratory study of evaluating the fatigue characteristics of hot-mix asphalt (HMA) mixtures using different testing methods. In this study, the fatigue performance of HMA mixtures was evaluated with the Superpave indirect tension (IDT) tests and beam fatigue test. The HMA mixtures containing 0%, 10%, 20%, and 30% of recycled asphalt pavement (RAP) were plant prepared with one source of aggregate, limestone, and one type of binder, PG 64–22. The fatigue properties tested included indirect tensile strength (ITS), failure strain, toughness index (TI), resilient modulus, DCSEf, energy ratio, plateau value, and load cycles to failure. The results from this study indicated that both Superpave IDT and beam fatigue tests agreed with each other in ranking the fatigue resistance of mixtures when proper procedures were followed.  相似文献   

15.
高寒地区水泥混凝土桥面沥青铺装层抗疲劳开裂性能分析   总被引:1,自引:0,他引:1  
混凝土桥面沥青铺装层在使用期间产生的疲劳开裂是世界各地桥面铺装常见的问题,该文依托内蒙古教来河大桥采用有限元分析软件ANSYS对于高寒地区混凝土桥面沥青铺装层的疲劳开裂性能进行分析研究。分析提出高寒地区混凝土桥面沥青铺装层深度0~2 cm区域可作为铺装层内部常温拉应力的峰值分布区域;铺装层内的常温拉应力均随着上面层/下面层厚度的增加而减小;通过增加高寒地区混凝土桥面沥青铺装层的厚度来改善桥面铺装层的抗疲劳性能。  相似文献   

16.
Fatigue crack is a main form of structural damage in flexible pavements. Under the action of repeated vehicular loading, deterioration of the asphalt concrete materials in pavements, caused by the accumulation and growth of micro and macro cracks, gradually takes place. The indirect tensile fatigue testing (ITFT) was carried out on three types of asphalt concrete materials comprising a high stiffness Gilsonite modified wearing course (GM-ACWC), stone mastic asphalt (SMA) and conventional asphalt concrete wearing course (ACWC) to establish fatigue damage model and failure criteria. Fatigue damage model, based on continuum damage approach, to describe the formation of micro-cracks and crack propagation was developed for the wearing course materials. With the fatigue damage model, finite element analysis was carried out to study the crack resisting performance of the three wearing course materials in a flexible pavement structure.  相似文献   

17.
This paper reports on the potential benefits of micro- or nano-sized materials for asphalt mixtures used on pavements, specifically when they are exposed to water or deicing solutions. Asphalt mixtures were prepared with various amount of nanoclay and/or carbon microfiber, and compacted using the Superpave? gyratory compactor. Moisture susceptibility and deicer impacts were assessed by exposing the samples to water or deicing chemicals (NaCl, MgCl2 and CaCl2), and seven freeze–thaw cycles, in a modified AASHTO T283 test. Comparisons of micro- or nano-modified asphalt mixtures exposed to deicers are made based on results of indirect tensile strength tests, which preliminarily demonstrate the great potential of using microfibers and nanoclays in asphalt mixture for improved performance. Based on the results, it was found that the addition of nanoclay and carbon microfiber would improve a mixture’s moisture susceptibility performance or decrease the moisture damage potential in most cases. The detailed effects of deicing solutions on the tensile strength of micro- or nano- modified asphalt mixture are discussed in this paper.  相似文献   

18.
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.  相似文献   

19.
The objective of this study is to the use of municipal solid waste incinerator (MSWI) fly ash as a partial replacement of fine aggregate or mineral filler in stone matrix asphalt (SMA) mixture. For saving natural rock and reusing solid waste, basic oxygen furnace slag (BOF slag) was used as part of coarse aggregate. And this makes SMA mixtures contain more than 90% solid waste materials by mass. A comparative study of the performance of two mixes designed using superior performance asphalt pavements (SUPERPAVE) and Marshall mix design procedures was carried out in this research. Samples from both mixes were prepared at the design asphalt contents and aggregate gradations and were subjected to a comprehensive mechanical evaluation testing. These tests included Marshall stability, water sensibility, resilient modulus, fatigue life and rutting. In all the performed tests SUPERPAVE mixtures proved their superiority over Marshall mixtures. TCLP test for environmental impact indicated that asphalt is an effective stabilization and solidification agent for heavy metal in MSWI ash. The heavy metal leachates in TCLP tests have great positive correlation with their initial concentration in waste. But Ni is an exception that lower initial concentration leaded to higher cumulative leaching rate.  相似文献   

20.
In recent years, warm mix asphalt (WMA) is widely used for reducing energy requirements and emissions in hot mix asphalt (HMA) industry. In addition, the use of rubberized asphalt in the past has proven to be economical, environmentally sound and effective in improving the performance of pavements across the US and the world. The objective of this research was to investigate the mixture performance characteristics of rubberized warm asphalt mixtures, and their correlation with binder properties, through a series of laboratory tests (e.g., viscosity, dynamic shear rheometer (DSR), and bending beam rheometer (BBR)) conducted on the binders, and obtaining the indirect tensile strength, rutting resistance, and resilient modulus of various mixtures. The results of the experiments indicated that the use of crumb rubber and WMA additive in HMA can effectively improve the engineering properties of these mixes at lower mixing and compacting temperatures and some statistical correlations between rheological and/or engineering properties were developed successfully.  相似文献   

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