新旧沥青融合多尺度评价研究

应用纳米级技术和宏观力学技术展开对RAP料中旧沥青对新沥青结合料结构和性能的影响,并且对新旧沥青之间的融合程度进行评估。对新沥青、RAP料中抽提出的旧沥青及新旧沥青混合而得的复合沥青进行不同的原子力显微镜试验,除此之外,通过再生沥青的DSR试验和动态模量试验评估得到的新旧沥青融合程度与应用原子力显微镜试验得到的结果相比较。结果表明微观和宏观研究结果具有一致性。     

Partial evaluation in Rank Aggregation Problems

Solving a problem by using metaheuristic algorithms requires the evaluation of a large number of potential solutions. This paper presents a theoretical and experimental study of the application of partial evaluation in the Rank Aggregation Problem (RAP). Partial evaluation just computes the part of the objective function that is affected by the modifications introduced by certain operators. In particular, we study some of the most common mutation/neighboring operators that are used in problems defined in the space of permutations, namely insertion, interchange and inversion. The theoretical study shows that the complexity of evaluating the original objective function can be reduced from quadratic to linear by using partial evaluation after applying insertion and interchange. Regarding the experimental study, it shows that for the insertion and interchange operators, the running time for the evaluation of the objective function may be reduced by a factor of 10 (30) for problems with more than 50 (100) items to be ranked. In the case of the inversion operator the amount of time saved time is not so large, although it is still significant.     

Effects of heat treatment on microstructure and mechanical properties of Cr–V–Mo steel processed by recrystallization and partial melting method

The phase segregation of semisolid processed products resulted in an inhomogeneous microstructure and poor mechanical properties of such products. Optimal subsequent heat treatments including quenching and tempering with various processing parameters were conducted to improve the quality of RAP (recrystallization and partial melting) processed Cr–V–Mo steel. The microstructure characteristics and mechanical properties, such as hardness, tensile strength, elongation, impact toughness, and resistance to high-temperature wear, of specimens subjected to various heat treatments were investigated. When the RAP-processed specimen was quenched from 1050 °C after isothermal holding for 480 s and then tempered twice at 560 °C for 2 h, microstructural evolution took placed in both former solid-phase and liquid-phase regions. The weakening of phase segregation, the redistribution of carbides, and the release of residual stress occurred during this heat treatment strategy caused a good combination of mechanical properties.     

SSTT和RAP方法得到的ZK60镁合金的组织变化和力学性能

研究了分别由半固态热成形方法（SSTT）和部分重熔再结晶方法（RAP）得到的 ZK60镁合金在一定温度下显微组织随等温时间的变化和触变成形试样的力学性能。结果表明,合并长大机制在SSTT合金的组织变化中占主导地位,熟化机制在RAP 合金的组织变化中起主要作用。在相同的等温条件下,与SSTT方法相比,RAP方法可以得到更细小的半固态显微组织,RAP合金组织比SSTT合金组织更圆整。由SSTT方法和RAP方法得到的ZK60镁合金触变成形后均得到了较理想的成形件,触变成形工艺提高了材料的力学性能。与 SSTT 合金相比, RAP合金具有更优越的力学性能。     

计费清算国际漫游清算门户TAP3标准的介绍

TAP3是由MOUTADIG组根据GSM移动业务发展状况及各运营商之间国际漫游账务清算的实际状况，在TAP1、TAP2、TAP2 的基础上制定的。MOU组织通过件，规定从2000年9月起，在国际漫游账务清算中开始使用TAP3(3．1)件格式，同时实现对TAP3格式的件的拒收和回退处理(RAP1．1)。到现在，TAP3版本已经从3．1升级到3．10，支持的业务种类也在不断增加。本系统介绍了GSM国际漫游清算业务的总体生态环境，以及TAP3对于国际清算服务的全方面的影响。通过对TAP3支持的主要通信业务、重要清算业务流程等进行研究，制定了中国移动BOSS支撑体系对于TAP3的实现策略与实施方案。     

RMIPv6中RAP发现算法的研究与改进

现有的RMIPv6协议中区域锚点（RAP）的发现算法是基于距离度量的,本文在分析了这种算法存在的不足后给出了一种新的基于时间度量的区域锚点发现算法。该算法能根据移动节点（MN）的移动性来选择合适的RAP。通过算法评估证明了其优于原有方案。     

再生沥青混合料的黏弹性动态响应及疲劳性能

为了分析废旧沥青路面材料(RAP)对热拌沥青混合料的黏弹性动态响应及疲劳性能的影响,设计了不同RAP掺量(10%、20%、30%)及不同级配(AC-13和AC-16)的沥青混合料,采用沥青混合料性能试验仪(AMPT)在不同温度和加载频率下的动态模量,之后采用时间-温度等效原理,确定了不同沥青混合料的动态模量主曲线;并对不同沥青混合料进行了单轴拉伸疲劳试验,通过简化的黏弹性连续损伤模型(S-VECD),确定了不同级配、不同RAP含量的沥青混合料的损伤特征曲线(C-S),及基于能量的疲劳失效标准与疲劳加载次数之间的关系(GR-Nf).结果表明:沥青混合料的动态模量随着温度的升高、加载频率的降低而降低,温度越低、频率越高,沥青混合料越接近弹性体,反之越接近黏性体;从不同级配的沥青混合料的动态模量主曲线中可以看出,RAP含量越高,其动态模量越高,但总体来看相差不大.疲劳试验及分析表明:RAP含量较高时,其疲劳性能较低,表明其应力松弛能力较差,因此应更加关注再生沥青混合料的抗疲劳性能.     

沥青路面就地热再生关键技术应用研究

针对宁夏高速公路沥青路面出现的车辙、桥头跳车、局部拥包等病害,结合养护维修工程的实际,采用就地热再生施工技术对病害路段进行修复.通过试验分析了再生剂用量对混合料性能的影响,给出了采用Superpave技术设计再生沥青混合料的步骤.得出了不同再生剂掺量与沥青三大指标的的对应关系,根据试验结果确定添加沥青用量4.5%的再生剂、级配添加25%新料后再生混合料级配满足目标要求,新料的沥青用量为2.5%,合成再生混合料的沥青用量为4.2%.沥青路面就地热再生技术修复路面可充分利用旧有材料,降低铺路成本,具有比较重要的实际应用意义.     

Reconsideration of the fatigue tests for asphalt mixtures and binders containing high percentage RAP

When applying reclaimed asphalt technology in a flexible pavement project, most performance concerns are related to low temperature and fatigue cracking since the stiffness of the HMA mixture could dramatically increase through adding a high percentage of reclaimed asphalt pavement (RAP) material. The purpose of this study is to evaluate asphalt mixtures with high RAP contents, prepared using two RAP addition methods, for their performance based on fatigue-cracking resistance rather than relying on volumetric properties. Asphalt mixture samples were prepared with three RAP binder content replacement percentages (30, 40 and 50%) using two preparation methods: the as-is RAP gradation (traditional method) and the splitting of the RAP gradation into coarse and fine fractions (fractionated method). Asphalt mixture beam fatigue and binder fatigue time-sweep tests were performed. Beam fatigue samples also underwent freeze–thaw cycling for freeze–thaw damage evaluation. Rather than basing the performance based solely on S–N_f curves to illustrate the fatigue performance, the beam fatigue test data was analysed through a dissipated energy approach. Faster fatigue degradation was observed for the 40% RAP binder and beam mixture when subjected to repeated loading. From a morphology aspect, this can be explained by the binder’s phase separation and physical hardening effects.     

Laboratory characterisation of asphalt mixes containing RAP and RAS

Due to its economic and environmental benefits, using reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) in new hot-mix asphalt (HMA) has become an integral part of today's asphalt industry. The advantages of using RAP and RAS in HMA are not limited to economic and environmental benefits, and may result in improving a number of mix performance characteristics including rutting and resistance to moisture-induced damage. Despite aforementioned benefits, concerns over premature pavement distresses resulting from using RAP and RAS limit their usage in HMA. Furthermore, because of the lack of mechanistic performance data, use of new mixes containing RAP and RAS remains limited. Therefore, the present study was undertaken to investigate the effects of using different amounts of RAP and RAS on laboratory performance of HMA, and to generate valuable input design parameters for implementation of the mechanistic-empirical pavement design guide (M-EPDG), using local materials. Four types of base course mixes containing 0% RAP, 25% RAP, 40% RAP and 20% RAP+5% RAS, and three types of surface course mixes containing 0% RAP, 25% RAP and 20% RAP+5% RAS were tested. Laboratory tests were conducted to evaluate stiffness, low-temperature cracking, fatigue life, rut and moisture-induced damage potential of the mixes. It was found that dynamic modulus and creep compliance of the asphalt mixes increase and decrease, respectively, with an increase in the amount of RAP and/or RAS used in the mix. Fatigue life was found to increase with increasing RAP content up to 25%, and to decrease when the RAP and/or RAS content exceeded 25%, or when RAS was used in the mix. It should be noted that this conclusion was drawn based on a 15% increment in RAP content. Hamburg wheel tracking (HWT) test results showed increased resistance to rutting and moisture-induced damage, with an increase in the amount of RAP and/or RAS. However, the tensile strength ratio test results were not confirmed by HWT. The findings of this study are expected to be helpful in understanding the effects of using different amounts of RAP and RAS on the performance of asphalt mixes produced using local materials. Furthermore, valuable design input parameters, developed in this study for new mixes containing RAP and RAS, may be used for calibration of the M-EPDG input parameters, with local materials.