摘要:通过对70#道路石油沥青在蒸馏水、酸、碱和盐溶液中浸泡前后的红外光谱(FTIR)测试,分析了水溶液的pH值和盐浓度对沥青在水溶液侵蚀过程中特征官能团的影响规律.结果表明,随着水溶液浸泡时间的延长,70#道路石油沥青的羰基指数和亚枫基指数逐渐增大,沥青在水溶液浸泡下发生了氧化;与蒸馏水相比,酸、碱和盐溶液使沥青羰基和亚枫基含量的增加更明显;酸碱性溶液中的酸碱性越大,沥青氧化越严重,其中,pH11碱溶液的氧化作用大于pH3的酸溶液;盐溶液中盐的质量分数越大,沥青的氧化程度越严重,质量分数为30%的Na2 SO4溶液对沥青的氧化作用最大.%Infrared spectrum (FTIR) tests on 70 # asphalt under distilled water,acidic water,alkaline water and neutral salt solution were carried out to analyze the the influence law of aqueous solution pH and salt concentration on asphalt characteristic functional groups in the process of erosion.The results indicate that the carbonyl and sulfoxide indices of 70 # asphalt increase after moisture aging as the extension of aqueous solution immersion time,due to the asphalt oxidation in aqueous solution.Compared with the distilled water,acid,alkaline and salted solutions show more destructive,and the greater the concentration of the solution,the more serious the oxidation of asphalt.The oxidation effect of pH11 alkali solution is greater than that of pH3 acid solution.Besides,the greater the concentration of salt in the salt solution,the more serious the oxidation degree of asphalt,and the solution with 30% Na2SO4 presents the most serious destructiveness.
摘要:The influence of two types of interface modifier (oil-soluble and water-soluble) and the corresponding modification process on the adhesion performance of acidic aggregate and asphalt was studied by puff-out test.And the modification mechanism was analyzed by the scanning electron microscopy and DSR rheological analysis technology.The results show that,due to the interface modifier covered evenly on the surface of stone through the membrane modification process,the surface properties of aggregate is changed and the adhesion performance of aggregate and asphalt is improved,and then the pavement performance is also improved.%通过拉拔试验研究两种体系的界面改性剂(油溶性、水溶性)及配套改性工艺对酸性集料与沥青粘附性能的影响,使用扫描电子显微镜与DSR流变分析等技术手段研究改性机理.结果表明,界面改性剂通过薄膜改性工艺均匀的覆盖于石料表面,改变了集料的表面性质,可提高集料与沥青粘附性能,进而提高沥青路面的路用性能.
摘要:预应力混凝土变截面箱梁桥在施工和运营过程中,跨中底板较易出现纵向裂缝.以某预应力混凝土刚构箱梁桥为研究对象,运用平面杆系结构与空间局部实体结构联合分析的方式,对箱梁桥跨中底板合龙束径向力的横向效应进行分析研究.结果表明,合龙段底板出现纵向裂缝主要是由预应力钢束产生径向力的横向效应引起的.针对底板纵向裂缝提出相应的防治措施并进行有限元模拟分析,与实桥的现场荷载试验相对照,验证了加固措施对箱梁底板横向受力有较明显的改善作用.%During the construction and operation of the prestressed concrete variable cross-section box girder bridge,it is easy to appear the longitudinal cracks in the midspan slab.Taking a prestressed concrete rigid frame box girder bridge as the research object and using the combination analysis of plane bar structure and space local entity structure,the transverse effect of the radial forces in closure tendon of the box girder bridge was analyzed and studied.The results indicate that the longitudinal cracks at the bottom of the closure section,are caused by the transverse effect of radial forces produced by the prestressed tendon.The corresponding prevention measures were put forward according to the vertical cracks in the slab,and the finite element simulation analysis was carried out.Compared with the load test results of the actual bridge,it is verified that the strengthening measures have obvious improvement effect on the transverse stress of the slab of the box girder.
摘要:Based on Xiaobeishan NO.1 tunnel of Jie Hui highway in Guangdong province,combining with the methods of theoretical analysis,field blasting test and numerical analysis,the blasting load of Xiaobeishan tunnel is simplified and the load situations on the equivalent boundary and the excavated contour surface are determined.The dynamic response characteristics of tunnel under blasting load and the influence of different blasting parameters on reducing blasting vibration are researched considering the influence of blasting load on tunnel and the related problems.Based on the simulation analysis of the factors influencing blasting vibration,the related factors and the vibration velocity distribution along the tunnel under different spacing and the rule of the peak velocity distribution in section are discussed.%以广东省揭惠高速公路小北山1号隧道为研究背景,采用理论分析、现场爆破试验和数值分析相结合的手段,简化小北山隧道爆破荷载,确定等效边界、开挖轮廓面上的荷载情况.围绕爆破荷载对隧道的影响及相关问题,研究隧道在承受爆破荷载时的动力响应特性和不同爆破参数对减振爆破的影响.针对爆破振动影响因素进行模拟分析,讨论相关影响因素和邻近隧道衬砌在不同间距下沿隧道轴向的振速分布分析及截面峰值振速分布的规律.
摘要:通过控制不同紫外老化时间和老化温度,研究两种变量对高紫外辐照下的沥青紫外老化的影响和沥青紫外老化机理.钻芯取样后进行紫外老化实验,然后抽提沥青测量其性能.流变性能测试结果表明,老化时间越长,结果越偏离规范老化;老化温度越高,光热耦合老化现象越严重.红外测试结果显示,沥青中某些基团吸收紫外光能量后被氧化生成羰基,SBS改性剂吸收能量后被氧化降解.在本实验所采用的条件下,温度比老化时间对老化程度影响更大,促进老化作用更为明显.%The effects of two variables on the UV aging of asphalt and the aging mechanism of asphalt were studied by controlling different UV aging time and different aging temperature.The UV aging test was carried out after drilling samples,and the performance was measured after extracting the asphalt.The results of rheological properties show that the longer the aging time,the aging results further deviation from the standard;the higher the aging temperature,the more severe of light-heat coupling aging.The results of FTIR show that some of the groups have been oxidized to carbonyl after absorbing ultraviolet light energy in the asphalt,the SBS modifier is oxidized and degraded after absorbing energy.Under the conditions used in this experiment,the parameter temperature has a greater effect on the aging degree than aging time,and the aging effect is more obvious.
摘要:在不同温度和应力条件下对AC-20沥青混合料进行了车辙轮碾试验,同时利用试验结果对几种车辙评价指标进行了对比分析.研究表明,动稳定度指标随温度和应力改变存在异常变化,不能够比较全面的评价沥青混合料的车辙性能;综合稳定指数和变形率两个车辙评价指标与车辙深度的相关性较之动稳定度更好.在室内车辙试验的基础上,综合稳定指数和变形率能够更合理的评价沥青混合料的高温车辙性能.%Rutting test on AC-20 asphalt mixture was conducted under different conditions of temperature and stress states,and several rutting evaluation indexes were compared based on the test results.The results show that the dynamic stability index changes abnormally with temperature and stress and will not be able to comprehensive evaluation the rutting performance of asphalt mixture.The correlation between complex stability index,deformation rate and rutting depth is better than that of dynamic stability.Based on the rutting test,the complex stability index and deformation rate can evaluate the high temperature rutting performance of asphalt mixture more rationally.
摘要:Based on the Xiao Beishan No.1 tunnel engineering of Jie Hui highway in Guangdong province,the golden section method and displacement back analysis are conducted to obtain the geotechnical parameter elastic modulus E and cohesion c with the geotechnical engineering analysis software FLAC3D.The measured data of section K14+640 is selected to check the accuracy of numerical results and the error is small.The results show that it is reliable to determine rock mechanics index by displacement back analysis.%本文以广东省揭惠高速公路小北山1号隧道工程为背景,结合岩土工程分析软件FLAC3D,采用黄金分割法,进行位移反分析,得到了围岩参数弹性模量E和粘聚力c,并选用K14+640断面的实测数据加以验证,计算结果误差较小.研究结果表明,采用位移反分析获取岩体力学指标是可靠的.
摘要:通过对沥青冷补液蒸发实验,模拟沥青冷补液中的稀释剂在自然环境中大部分挥发后的状态,解释说明沥青冷补混合料的强度随着时间发展的原因.结果表明,自制沥青冷补液经过蒸发实验后,冷补液稀释剂的挥发量达80%以上,已达到稀释剂挥发水平要求.由DSR的高温扫描数据分析,经过蒸发试验后的沥青冷补液高温性能与基质沥青相近,特别是当沥青冷补液中的自制添加剂掺量为4%时,其高温性能甚至要优于基质沥青,BBR实验的研究结果表明稀释剂挥发后的沥青冷补液有着优越低温性能.%Asphalt cold rehydration is the key component to affect the performance of cold patch asphalt mixture.The performance research of asphalt cold rehydration at high and low temperature,through the evaporation experiment of asphalt cold rehydration,simulated the evaporating state of asphalt cold rehydration after most of diluent volatile in natural environment.And the reason of the strength development of cold asphalt mixture with time was explained.The results show that the volatilization rate of cold liquid diluent reaches more than 80% after the evaporation test of homemade asphalt cold rehydration,and the volatile level meets the requirement of diluent.By the high-temperature scanning data analysis of DSR,the high temperature performance of asphalt cold rehydration after the test is similar with that of matrix asphalt.Especially when the homemade additive dosage reaches 4% in asphalt cold rehydration,the high temperature performance of asphalt cold rehydration is better than that of matrix asphalt and its low temperature performance becomes better after the volatilization of diluent in the BBR experimental,which provides a basis for improving the late performance of asphalt cold rehydration.
摘要:The feasibility of reusing resources of cement asphalt mortar (CA) with rice husk ash and steel slag was studied.The optimal proportion of rice husk ash and steel slag in CA mortar was determined by a series of verification of construction performance and physical and mechanical performance for different dosage of rice husk ash,steel slag in CA mortar.By using XRD and SEM,the mechanism of macro performance change with the optimal proportion of rice husk ash and steel slag in CA mortar was revealed from the micro perspective.The results show that the construction performance and physical and mechanical performance of CA mortar change little when the dosage of steel slag is lower than 20% and rice husk ash content lower than 60% in composite cementitious materials.All the performance will be the best with the dosage of BOFS 10%,RHA 45% and cement 40%.The Antifreeze performance and anti-dry shrinkage of CA mortar will improve at the same time.%将稻壳灰、钢渣加入到CA砂浆中,研究其资源再利用的可行性.通过对各组不同稻壳灰、钢渣掺量的CA砂浆进行施工性能和物理力学性能验证,得到运用到CA砂浆中稻壳灰和钢渣的最佳配比.并通过X射线衍射分析、扫描电镜分析等分析手段,从微观角度阐述最佳配比稻壳灰和钢渣的加入对CA砂浆所产生的宏观性能改变的机理.结果表明,当在复合胶凝材料中钢渣质量分数低于20%,稻壳灰质量分数低于60%应用到CA砂浆中时,对CA砂浆施工性能和物理力学性能影响不大,并且以10%的钢渣,45%的稻壳灰和40%的水泥复合时CA砂浆的各项性能最佳,此时CA砂浆的抗冻性能和抗干缩性能同时得到了提升.
摘要:In order to more accurately reflect the performance of asphalt pavement in service,full-thickness rutting specimens were used in the test to ensure the simulation effect.Meanwhile,the multifunction pavement material life analyzer machine was used to control the test environment,and the UV light intensity was set to simulate solar radiation and produce a temperature gradient,which was used to observe the Asphalt pavement performance.The results show that the rutting damage is composed of two stages:compaction and stabilization.Under the same conditins,the higher temperature will significantly reduce the dynamic stability,results in the late time of rutting damage into the stable phase.UV light will form a significant gradient temperature field in the specimen,and the higher the intensity of the UV light,the higher the temperature gradient will form in the specimen.Higher UV intensity will significantly reduce the dynamic stability,and the time of rutting damage into the stable phase will be later.%为了更加准确的反应沥青路面在服役时的性能,试验采用全厚式车辙试件以保证模拟效果,使用多功能路面材料全寿命分析仪对测试环境进行控制,设置温度梯度以观察温度对沥青路面服役性能的影响,设置紫外光强模拟太阳辐射并产生温度梯度.结果表明,车辙破坏有压密和稳定两个阶段,其他条件相同的情况下,更高的温度会显著降低动稳定度,且车辙破坏进入稳定阶段的时间点更晚.紫外光会在试件中形成显著的梯度温度场,且紫外光强度越高试件中形成的温度场梯度越大.更高的紫外强度会显著降低动稳定度,且车辙破坏进入稳定阶段的时间点更晚.
摘要:The conventional physical properties,rheological properties,and the change of four-component and functional groups structure of asphalt aging were studied based on the photo-thermal aging analysis of AH-70 asphalt mixture matrix under the different UV irradiation times (15~45 d) and different temperatures (8~32 ℃).The results show that UV irradiation time and temperatures present a linear relationship between asphalt residual penetration,softening point increment,viscosity aging index.Photo-thermal induces the superimposed effect in the process of asphalt aging,and the temperature effect is predominant.The complex modulus of asphalt quantity increases gradually and the phase angle decreases with the increase of ultraviolet irradiation time and temperature.Meanwhile,asphalt components change apparently with temperature after the analysis of asphalt composition and structure.Temperature and and ultraviolet radiation promote the formation of carbonyl and sulfoxide groups respectively,which are the main causes of asphalt photo-thermal coupling aging.%将AH-70基质沥青混合料在不同紫外光辐照时长(15~45 d)与不同温度(8~32℃)下进行光热老化,研究老化沥青的常规物理性能、流变性能以及四组分与官能团结构的变化.结果表明,紫外光辐照时间及温度均与沥青的残留针入度、软化点增量和粘度老化指数呈线性关系,且光热对沥青老化过程产生了叠加效应,其中温度影响占主导.随着紫外光辐照时间及温度的增加,沥青的复合模量逐渐增加、相位角逐渐减小.同时,沥青组分与结构分析发现沥青组分随温度变化更为明显;温度和紫外光分别促进沥青的羰基和亚砜基的生成,是造成沥青光热耦合老化的主要原因.
摘要:The benzophenone-4 was adopted to the organic-intercalated modification of LDHs to investigate the effect of the BI-LDHs on the anti-aging properties of the asphalt mixture.Two dosages of BILDHs (3% and 5%) were set up,and the accelerated aging test and indoor ultraviolet aging tests were conducted to simulate the short-term thermo-oxiditive aging and ultraviolet aging of two kinds of asphalt mixtures (AC-13 and AC-20) respectively.Then the control strain fatigue test was used to test the fatigue life and fatigue limit of asphalt mixture before and after aging.The results show that,before aging,the fatigue life of asphalt mixtures decrease with the addition of BI-LDHs;after aging,the fatigue life of all asphalt mixtures dereases,but the fatigue life of BI-LDHs modified asphalt mixtures is higher than that of asphalt mixtures without BI-LDHs,which indicates that BI-LDHs can delay the aging process and enhances the anti-aging performance of asphalt mixtures obviously.%采用二苯酮-4对LDHs进行有机插层改性,研究二苯酮-4有机插层改性LDHs(BI-LDHs)对沥青混合料抗老化性能的影响.拟定质量分数为3%和5%两个BI-LDHs掺量,分别采用沥青混合料加速老化试验和室内紫外老化模拟试验对AC-13和AC-20两种沥青混合料进行短期热氧老化和紫外老化,采用控制应变的疲劳试验,对老化前后沥青混合料的疲劳寿命和疲劳极限进行研究.结果表明,老化前,BI-LDHs使得沥青混合料疲劳寿命有所降低;老化后沥青混合料的疲劳寿命均减小,但老化后BI-LDHs改性沥青混合料的疲劳寿命反而大于未添加改性剂沥青混合料,表明BI-LDHs能够延缓老化过程,显著提高沥青混合料的抗老化性能.
摘要:通过对实际沥青路面中取回的芯样进行系统分类并对其进行Leutner剪切实验,探究路面层间抗剪切力与路面位置,老化程度及病害的关系.结果表明,路面的层间抗剪切性能与行车位置及路面老化程度具有一定对应关系,运用Leutner剪切实验判断路面残余寿命是切实可行的.%The core samples retrieved from the actual pavement were classified systematically and the Leutner shear test was carried out to explore the relationship between the interlaminar shear resistance and position aging degree and disease of the pavement.The results show that the interlaminar shear resistance of pavement has a certain relationship with the driving position and aging degree,and it is feasible to evaluate the residual life of pavement using Leutner shear test.
摘要:通过制备不同掺量的硅藻土改性沥青,测试其基本性能指标.采用动态剪切流变仪(DSR)和弯曲梁流变仪(BBR)对基质沥青和改性沥青的高、低温性能和疲劳性能进行研究.结果表明,硅藻土的加入使沥青针入度和延度降低,软化点和粘度升高.改性沥青的复合模量和车辙因子随硅藻土掺量的增大而增大.适宜掺量的硅藻土能提高沥青的疲劳寿命和蠕变速率,改善其疲劳性能和低温抗裂性能.综合来看,硅藻土的合理掺量为10%~12%.%The basic performance indicators of modified asphalt with diatomite at various contents were tested.Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR) were also used to e valuate the high and low temperature performance and fatigue performance of base asphalt and modified asphalt specimens.The results show that the penetration and ductility of asphalt decrease and the softening point and viscosity increase with the addition of diatomite.And the complex modulus and rutting factor of modified asphalt increase with the increase of the diatomite content.The fatigue life and creep rate of asphalt are improved with the appropriate content of diatomite,which benefits to fatigue life and crack resistance of modified asphalt.In general,the optimum content of diatomite is 10%~12%.
摘要:为研究废食用油及新沥青对废旧混合料再生性能的影响,利用浸水马歇尔、低温弯曲蠕变、高温车辙及四点弯曲疲劳寿命等实验,分析再生沥青混合料的路用性能;结合棒状薄层色谱及热裂解气象色谱分析,研究再生沥青化学组成的变化.结果表明,废食用油与新沥青的添加能提高老化沥青中轻质油分含量、降低沥青质含量,使胶体结构趋向溶胶型;复合再生剂的添加能改善老化混合料的低温性能、水稳定性能及疲劳性能,但对其高温性能改善效果有限.%In order to evaluate the regeneration effect of waste cooking oil and virgin asphalt on recycled asphalt pavement (RAP),the road performance of rejuvenated mixture were analyzed by experiments such as immersion Marshall,low-temperature bending creep,high-temperature rutting and four-point bending fatigue life.The thin layer chromatography and Pyrolysis Gas Chromatograph-Mass Spectrometer-computer (Py-GC/MS) analysis were carried out to investigate the chemical compositions and microstructure of rejuvenated asphalt.The results indicate that the addition of WCO and virgin asphalt can improve the content of SARA (saturates,aromatics,resins and asphaltenes) fractions of aged asphalt,resulting in the colloid structure tending to sol type.Moreover,the low-temperature performance,water stability and fatigue resistance properties of aged asphalt mixture are improved due to the addition of complex regenerant,while the high-temperature stability performance remains to be further improved.
摘要:络合型功能外加剂是一种可赋予混凝土裂缝自修复功能的添加剂.文中研究了络合型外加剂对水泥基材料的凝结时间、孔隙率、微结构、力学性能,以及裂缝自修复能力的影响.结果表明,络合型功能外加剂可降低水泥基材料的孔隙率,改善其密实度,明显提高其力学性能,并赋予其优良的裂缝自修复能力.与普通砂浆相比,掺加水泥量0.5%的络合型功能外加剂的砂浆的孔隙率降低了18.1%,28 d的抗折、抗压强度分别提高了15.5%和26.8%,0.27 mm的裂缝可实现自修复.%The chelating functional admixture is a kind of additive with self-healing ability to concrete cracks.The effects of the chelating functional admixture on the setting time,porosity,microstructure,mechanical property and crack self-healing capability of cement based materials were investigation.The results show that the chelating functional admixture can reduce the porosity of cement base material,improve the compactness and mechanical properties obviously,and make the structure has excellent crack self-healing ability.Compared with the ordinary mortar,the porosity of mortar with 0.5 % chelating functional admixture of cement dosage is reduced by 18.1%,the flexural strength and compressive strength at 28 curing days increased by 15.5% and 26.8% respectively,and the cracks of 0.27 mm can be self-healed.
摘要:通过对沥青老化与再生前后的常规物理性能与流变性能进行实验研究,对比分析废食用油和废润滑油对老化沥青物理与流变特性影响的差异性.结果表明,当废食用油和废润滑油的掺量分为7%,20%时,老化沥青的针入度、软化点、延度恢复至原样沥青的90%以上,而蠕变劲度模量低于原样沥青,蠕变速率大于原样沥青;复合模量、相位角以及车辙因子均低于原样沥青.这说明两种废油都可以软化老化沥青,可以作为沥青再生剂使用,但是不同废油对沥青再生的机理以及对不同沥青的再生效果仍需进一步研究.%The physical and rheological properties of aging and recycling asphalt were investigated by experimental research.The differences in physical and rheological properties of aged asphalt were compared with waste cooking oil and waste lubricating oil.The results indicate that,when the dosage of waste cooking oil is 7% and waste lubricating oil is 20%,the penetration,softening point and ductility of rejuvenated asphalts can be restored to more than 90% of the original asphalt.However,the creep stiffness modulus is lower and creep rate is higher than that of origin asphalt.Complex modulus,phase angle and rutting resistance factor of rejuvenated asphalt are lower than that of origin asphalt This result suggests that both waste cooking oil and waste lubricating oil can soften the aged asphalt,which can be used as the rejuvenator.But the rejuvenate mechanism of different waste oils to aged asphalt and the rejuvenate effect for different asphalt still need to be further investigated.
摘要:热诱导自愈合能够修复沥青混凝土裂纹,目前沥青混凝土感应加热自愈合评价均是基于整体强度恢复和整体平均温度的水平,缺乏对温度梯度分布及梯度愈合行为的深入研究.文中揭示了电磁感应诱导加热下沥青混凝土纵向的温度梯度分布情况,探明沥青混凝土加热的梯度愈合行为,研究了加热距离对温度分布的影响规律和加热次数对愈合效率的影响效果,解决了沥青混凝土的愈合行为随温度梯度分布如何变化的问题.%Induction heating induced healing can repair cracks in asphalt concrete efficiently.The existing evaluations on induction heating and healing of asphalt concrete are based on bulk strength recovery and average temperature of samples,lacking in-depth study on temperature gradient distribution and gradient healing behaviors.In this paper,the longitudinal temperature gradient distributions of asphalt concrete heated with induction heating at different heating distances were revealed,and the gradient healing behavior of asphalt concrete induced by induction heating was explored.The influence law of heating distance on temperature distribution and the effect of heating times on healing efficiency were analyzed,and the relationship between healing behavior and temperature gradient distribution was solved.
摘要:采用常规的车辙试验探究短期老化条件、不同放置时间(24,48,72 h),以及拌和楼拌和工艺对布敦岩沥青混合料高温性能的影响;采用单轴贯入试验对现场取芯试件的布敦岩沥青混合料抗剪强度进行研究.结果表明,短期老化后的布敦岩沥青混合料动稳定度高于未老化的布敦岩沥青混合料,且放置时间越长,短期老化对动稳定度的提升越明显;放置时间的延长有助于布敦岩沥青混合料动稳定度的增长,建议布敦岩沥青混合料车辙试验的试件放置时间为48 h.此外,岩沥青后加工艺拌制的布敦岩沥青混合料的高温性能优于常规工艺.%The effect of short-term aging condition and aging time (24 h,48 h and 72 h),and the mixing processes of the mixing plant on the high temperature performance of Buton Rock Asphalt Mixture were investigated by using the conventional rutting test.And the uniaxial penetration experiments were used to test the shear strength of field core samples of Buton Rock Asphalt Mixture.The results show that the dynamic stability of Buton Rock Asphalt Mixture after short-term aging is higher than that of the un-aged Buton Rock Asphalt Mixture,and the improvement of dynamic stability of Buton Rock Asphalt Mixture after short-term aging becomes more obvious as the standing time gets longer.The prolongation of the standing time contributes to the growth of dynamic stability of Buton Rock Asphalt Mixture.It is suggested that the standing time of Buton Rock Asphalt Mixture core samples should be 48 h before the rutting test.In addition,BRA-after-mixing process is better than the conventional process for the high temperature performance of Buton Rock Asphalt Mixture.
摘要:Using the 5 TSX/TanDEM high resolution radar images during 2017.02.29 to 2017.05.29,the research of double long highway subgrade deformation detection was carried out with the technique of differential Interferometric synthetic aperture radar (DInSAR).And the deformation law of frost heaving and thaw settlement was analyzed,combining with the data of embedded displacement sensor in survey region.The results show that the highway subgrade deformation results based on DInSAR interferometry are consistent with the results from the frost heaving meter on the deformation trend sequence.DInSAR technology using in Frost heaving and deformation monitoring of subgrade in sea sonal frozen soil zone has a good application effect.%采用差分雷达干涉测量技术,利用2017年2月19日-5月29日间的5景高分辨率TSX/TanDEM雷达影像,开展长双公路段路基形变探测研究,并结合研究区预埋位移传感器数据,进行路基冻胀融沉形变规律分析.结果表明,基于DInSAR干涉测量获取的公路路基形变结果与冻胀计结果,在时序形变趋势上具有较好的一致性,DInSAR技术在季冻区公路冻胀融沉形变监测方面具有较好的应用效果.
摘要:As the most widely used modified asphalt,SBS modified asphalt still cannot meet the requirements of extreme weather condition in South China and North China.The effect of carbon nanotubes on the high and low temperature properties of SBS modified asphalt was investigated in this paper.Penetration,softening point,viscosity,dynamic shear rheology and bending beam rheometer experiments revealed that carbon nanotubes improve the high and low temperature properties of SBS modified asphalt to some extent.Thermogravimetric test,asphalt four component analysis and fluorescence microscopy test showed a synergistic effect between carbon nanotubes and SBS.%SBS改性沥青作为应用最广泛的改性沥青,仍然难以满足中国南方和北方的极端恶劣气候要求.文中研究了纳米碳纳米管的掺入对SBS改性沥青高低温性能的影响.渗入度、软化点、粘度、动态剪切流变、弯曲梁流变仪的试验揭示了碳纳米管对SBS改性沥青高低温性能有不同程度的提高.热重测试、沥青四组分分析和荧光显微镜测试显示碳纳米管和SBS之间有协同作用.
摘要:The development of self-healing technology is very important for the maintenance of roads,but the aging in service will seriously affect the flow performance and self-healing properties of asphalt.Three kinds of LDHs were adopted for modified asphalt to explore the affect of LDHs on asphalt liquidity and self-healing performance.And then short-term thermal oxygen aging was analyzed to explore the affect of aging on asphalt liquidity and self-healing performance.The results show that the impact of organic modified LDHs on the complex modulus of asphalt is small,and the modified LDHs have better anti-aging performances.The variations of flow performance and self-healing performance of organic LDHs modified asphalt after short-term thermal oxygen aging are significantly less than those of LDHs modified asphalt and unmodified asphalt.%自愈合技术的发展对道路的养护至关重要,但是实际服役情况中的老化又会严重影响沥青的流动性能和自愈合性能.利用三种LDHs对沥青进行改性,探究LDHs对沥青的流动性和白愈合性能的影响.然后进行短期热氧老化,探究老化对沥青流动性能和自愈合性能的影响.结果表明,有机化改性的LDHs对沥青的复合模量的影响较小,且改性后的LDHs有更好的抗老化性能.短期热氧老化后有机化LDHs改性沥青的流动性能变化量和自愈合性能变化量明显少于LDHs改性沥青和未改性沥青.
摘要:粗集料是沥青混凝土的主要组成材料,其对沥青混凝土性能起着重要的作用.在ATB-25沥青稳定碎石中研究了玄武岩、石灰岩、安山岩三种集料的粗集料复掺方法及其对沥青混凝土性能的影响.研究了粗集料整体置换复掺法和粗集料分档复掺法两种类型的复掺方法.引入有效密度概念保证研究的准确性.结果表明,粗集料复掺可以有效改变沥青稳定碎石的体积性能.使用石灰岩粗集料可以提高沥青稳定碎石的抗水损害性能.复掺入碱性粗集料或表面粗糙的粗集料可以改善沥青稳定碎石的力学性能,粒径越大的粗集料对沥青稳定碎石的抗疲劳性能影响越小.%Coarse aggregate is the main composition of asphalt concrete,which plays a vital role in the performance of asphalt concrete.The method of compound coarse aggregate of three kinds of aggregate of basalt,limestone and andesite was studied and its effect on the properties of asphalt concrete was analyzed in the process of ATB-25 asphalt treated base mixtures.The concept of effective density was used to ensure the accuracy of the study.The results show that the compound coarse aggregate can effectively change the volume performance of asphalt treated base mixtures.The water damage resistance of asphalt treated base mixtures is improved with limestone coarse aggregate.The coarse aggregates with alkaline or rough surface improve the mechanical properties of asphalt treated base mixtures.The greater the particle size of the coarse aggregate,the smaller impact on the fatigue properties of asphalt treated base mixtures.
摘要:In order to improve the high temperature performance and pavement performance of asphalt pavement materials,porous asphalt concretes were prepared using steel slag as aggregates.And semiflexible pavement materials were made by grouting method.Rutting tests and indirect tensile tests were carried out to evaluate its performance.The results show that the rutting resistance and indirect tensile fatigue properties of the semi-flexible asphalt mixtures have a sharp increase compared with the matrix asphalt mixtures.Moreover,semi-flexible pavement materials prepared by steel slag have similar high temperature stability and road performance compared to the samples prepared by basalt.%为了提升沥青路面材料的高温性能和路用性能,使用钢渣作为集料制备多孔沥青混凝土,通过灌浆制备半柔性路面材料,利用标准车辙实验和间接拉伸实验对其性能进行表征,结果表明,抗车辙性能和间接拉伸疲劳性能相对于母体沥青混合料有大幅度提升,且采用钢渣集料制备的半柔性路面材料与采用玄武岩集料制备的半柔性路面材料相比,在高温稳定性和路用性能上相差不明显.
摘要:Creep model parameters (A,n,m) of AC-13,AC-20 and AC-25 asphalt mixtures,common ly used as the upper,middle and bottom layer in asphalt pavement,were determined by fitting the results of indoor rutting test at different temperatures.Finite element analysis based on the strain hardening creep model was carried out to to simulate the rutting evolution of mixtures under multi-stress rutting test and three layers rutting test.It is shown that the creep model can accurately simulate the rutting evolution of different asphalt mixtures at different stress and different temperature.This modeling approach can be used to predict the rutting evolution of different layers in asphalt pavement under actual traffic and climate conditions,which provides a basis for the asphalt mixture design and pavement structure optimization.%通过室内车辙试验结果拟合分析得到了不同温度下沥青路面上、中和下面层常用AC-13,AC-20和AC-25三种沥青混合料的蠕变模型参数(A,n和m).利用基于应变硬化蠕变模型的有限元分析,对多重应力和三层全厚式沥青混合料的车辙发展进行了模拟验证.研究表明,蠕变模型能够准确模拟不同沥青混合料在不同应力和温度条件下的车辙发展,其可用于预测沥青路面在实际交通和气候条件下的不同面层车辙发展.
摘要:基于Top-Down裂缝病害路段区分路况(优、中、差)现场钻取的芯样和路面板,室内分层(上、中、下面层)切割试件进行沥青抽提后三大指标试验、OT试验及小梁弯曲试验,对寒区Top-Down裂缝成因进行分析.试验结果表明,沥青结合料老化和混合料低温疲劳、低温收缩均为寒区Top-Down裂缝产生的原因.%In the disease road with Top-Down cracks,the core samples and pavement slabs are drilled and selected in different road conditions (excellent,medium and poor).The test of three major indexes (penetration,ductility,softening point) after asphalt extraction test,the OT test and the trabecular bending test are conducted on the samples cut into three layers (upper layer,middle layer,and lower layer) to analyze the cause of Top-Down cracks in cold regions.The test results show that the aging of asphalt binder,the fatigue and shrinkage at low temperature of the mixture are the causes of the Top-Down cracks formation in cold regions.
摘要:In order to analyze the effect of self-healing capsules on the performance of asphalt mixture,different percentages of self-healing capsules (0.00%,0.50%,0.75% and 1.00%) were added to asphalt mixture in the mixing process and a series of mechanical property tests (stability test,indirect tensile strength test,freeze-thaw splitting strength test,Kentucky Fort flying test and fatigue performance test) were performed on the samples drilled from the rutting slabs using rut instrument.The results show that the addition of self-healing capsules has a small influence on Kentucky Fort flying loss and has no effect on shattering resistance performance of asphalt mixture,The indirect tensile strength,water stability and fatigue properties of the asphalt mixture are increased when the dosage of self-healing capsules is 0.50%.When the dosage of capsules continue to increase,the mechanical properties will decrease seriously and even fail to meet the relevant specifications.%为研究自愈合胶囊对沥青混合料性能的影响,在沥青混合料拌和过程中分别掺入不同质量分数(0.00%,0.50%,0.75%,1.00%)的自愈合胶囊,利用车辙仪碾压成型后取芯进行稳定度、间接拉伸强度、冻融劈裂强度、肯塔堡飞散和疲劳性能实验.结果表明,沥青混合料肯塔堡飞散损失随自愈合胶囊掺量的增加变化不大,自愈合胶囊对混合料的抗掉粒性能基本没有影响;自愈合胶囊掺量为0.50%时,能够提高沥青混合料的间接拉伸强度、水稳定性和疲劳性能,继续增加胶囊掺量,上述性能将会严重下降,甚至不满足相关规范要求.
摘要:基于含软弱夹层围岩的力学计算和屈服破坏分析,根据软弱夹层的受力变形的特点,通过简化提出了计算夹层边界应力的组合梁结构模型,并推导出相应的方程组.以马家河隧道为例,求解对应方程组,并将理论计算结果与数值软件计算结果进行对比和误差分析,验证了模型的可行性.同时利用Mohr-Coulomb准则提出了评估围岩危险程度的ξ系数及其相应的计算公式,并将其应用于马家河隧道中含软弱夹层的围岩地段进行分析,根据ξ系数对围岩进行了危险等级分区,并结合位移分布进行对比分析.%According to the deformation characteristics of weak interlayer,a simplified composite beam structure model was proposed and a set of functions was deduced to calculate the stress of interlayer boundary,based on the analysis of surrounding rock with weak interlayer on mechanical calculation and yield failure.Taking Majiahe tunnel for example,the results of theoretical calculation and numerical software calculation results were compared and the error was analyzed after solving the corresponding equations.And the feasibility of the proposed model was verified.Meanwhile,the risk coefficient ξ and corresponding calculation formula were put forward to evaluate the dangerous level of surrounding rock with weak interlayer with Mohr-Coulomb criterion using in Majiahe tunnel.According to the coefficient ξ,the risk grade of the surrounding rock was devided.The results were analyzed combined with the displacement distribution.
摘要:In order to promote the use of porous steel slag as an asphalt pavement material,the basic properties of steel slag were analyzed.The results show that the water absorption rate of steel slag is nearly 4 times as much as that of limestone,which proves that steel slag is porous.AC-20 steel slag asphalt mixture was prepared using steel slag as coarse aggregate and limestone as fine aggregate.Compared with the preparation method of limestone asphalt mixture,the gradation design of steel slag asphalt mixture was optimized and the optimal asphalt content was analyzed by considering the influence of density difference between steel slag and stone.And the road performance of AC-20 steel slag asphalt mixture was analyzed by experiments.The results show that high temperature stability and water stability of steel slag asphalt mixture are better than those of limestone asphalt mixture,and the swelling property also meets the standard requirements.%为了促进多孔钢渣作为沥青路面材料的使用,对钢渣基本性质进行分析.结果表明,钢渣吸水率是石灰岩的近4倍,证明钢渣孔隙较多.采用钢渣作为粗集料,石灰岩为细集料来制备AC-20钢渣沥青混合料.通过与石灰岩沥青混合料制备方法对比,考虑钢渣与石料密度差异的影响.优化钢渣沥青混合料的级配设计,分析其最佳沥青用量.通过试验分析AC-20钢渣沥青混合料路用性能,结果表明,钢渣沥青混合料的高温稳定性与水稳定性能都优于石灰岩沥青混合料,其膨胀性能也满足规范要求.