To eliminate the gradation variability of reclaimed asphalt pavement (RAP) materials and improve the road performance of cold-recycled mixtures, this study analyses the gradation variability of recycled materials and conducts gradation design using the actual particle sizes of extracted aged materials. An optimisation method for the mix proportion of cold-recycled mixtures is proposed by combining the uniform method for design and the Bailey method for verification. A comparative study on the road performance of cold-recycled mixtures with two different gradations was then carried out. Based on low-temperature beam bending and semi-circular bending (SCB) tests, the low-temperature performance of the recycled mixtures was comprehensively evaluated from the perspectives of conventional analysis and energy analysis. Moreover, the correlation between fracture energy, strain energy density and the low-temperature indices specified in the current technical code was analysed to determine the low-temperature performance evaluation index for cold-recycled mixtures in severely cold regions. The results show that gradation design using only the sieving data of milled RAP materials will lead to an overall finer gradation of the recycled mixtures. For the optimised gradation verified by the uniform design and Bailey verification, the dynamic stability of the mixtures is increased by 9%~15% and the water stability is improved by 3%~6% under different cement contents. In addition, the flexural tensile strength and flexural tensile strain of the mixtures are increased by 3% and approximately 6%, respectively after gradation optimisation, indicating an improvement in low-temperature performance, with the optimal effect achieved at a cement content of 1.5%. Through the correlation analysis of fracture energy, strain energy density and flexural tensile strain, fracture energy is proposed as the low-temperature performance evaluation index for cold-recycled mixtures, and the recommended value of this index is determined to be 1000 J/m2 for severely cold regions in winter. The research results provide a theoretical basis for the gradation design and performance evaluation of recycled mixtures applied in severely cold regions.

The health of urban trees is jointly influenced by species-specific environmental adaptability and habitat heterogeneity, posing severe challenges for management. We investigated landscaping trees in Beijing, established a five-tier health evaluation system (healthy, sub-healthy, unhealthy, severe decline, and moribund) comprising 14 indicators. Then, we analyzed current health status and the influence of six typical habitats: dense forest, sparse forest, tree belt, tree pond, waterside, and buildingside. A total of 3654 trees were surveyed, which belonged to 80 species, 44 genera, 27 families. 71.7% of the trees were rated as sub-healthy or worse. The top 10 species by number of samples (46.3% of total) showed significant health variations. Ginkgo biloba, Platanus ×acerifolia, Ailanthus altissima, Catalpa bungei, and Pinus tabuliformis were classified as sub-healthy, while Styphnolobium japonicum, Fraxinus pennsylvanica, Populus tomentosa, Koelreuteria paniculata, and Prunus cerasifera 'Atropurpurea' were classified as unhealthy. G. biloba exhibited optimal performance in dead branch rate, crown form, and trunk injury severity. P. ×acerifolia exhibited optimal performance in foliage disease and pest severity, foliage density, trunk inclination degree, and tree vigor, whereas P. cerasifera 'Atropurpurea' showed the poorest performance in foliage disease and pest severity, leaf discoloration, and tree vigor. Tree health varied significantly across the six habitats, ranked as sparse forest > dense forest > waterside > buildingside > tree belt > tree pond. Trees in spare forest habitat exhibited favorable overall healthy. Dense forest habitat exhibited notable crown form deficiencies. Waterside habitat suffered higher foliage disease and pest severity. Buildingside habitat exhibited pronounced leaf discoloration. Tree pond habitat exhibited marked tree vigor decline. In conclusion, Beijing landscaping trees faced substantial health risks, G. biloba and P. ×acerifolia demonstrated strong urban adaptability, while P. cerasifera 'Atropurpurea' exhibited sensitivity; sparse forest habitat provided optimal growing conditions, whereas tree pond habitat imposed the most significant constraints on tree health.

Rapid urban development poses drastic changes in bird biodiversity. Trees in urban green spaces play an essential role in bird conservation, providing crucial nesting sites and food resources. The fruits of woody plants offer food resources for birds throughout most of the year, especially during winter. However, the dominant traits of woody plants that attract frugivorous birds to feed in urban green spaces during winter remain poorly understood. To evaluate the interaction network between frugivorous birds and heterogeneous woody plant species, and figure out how plant structure traits, fruit morphological traits, and fruit nutritional traits influence the diversity of frugivorous birds, a pilot sampling survey of frugivorous birds on 10 native woody plant species was conducted on a university campus in Hangzhou, China. The results show that (1) most frugivorous birds interact specifically with certain plant species in urban green spaces during winter; (2) plant-frugivorous birds interaction network showed a significantly low level of connectance, specialization, and nestedness; (3) in all functional traits of woody plants, fruit abundance (FA) contributes most to the richness and abundance of frugivorous birds; (4) in 3 types of functional traits, plant structure traits play dominant roles in determining the richness and abundance of frugivorous birds, with explanatory power of 24.43 % and 34.0 %, respectively. Moreover, combining plant structure traits and fruit traits can better explain the diversity of frugivorous birds. This study expands our knowledge of the effect of plant and fruit traits in attracting frugivorous bird diversity in urban green spaces during winter, which can provide insights for woody plant selection and planting design to conserve bird species diversity in urban areas.

Spontaneous plants play a crucial role in enhancing urban biodiversity despite the limited habitat space. Understanding the mechanisms of these plants occurrence and distribution is essential for promoting biodiversity in urban environments. Urban green spaces provide shelter and habitat for spontaneous plants, however, the complexity of urban environments and human disturbances make it challenging to identify the environmental filters affecting the diversity of spontaneous plants. We conducted a field study of 20 urban green spaces in Beijing, combining remote sensing interpretation and model-fitting methods to explore how surrounding landscape patterns and habitat attributes influence the diversity of spontaneous plants. A total of 174 spontaneous plant species, belonging to 48 families and 130 genera, were recorded. The surrounding landscape patterns, rather than habitat attributes, predominantly influence the species richness of spontaneous plants. We found that the species richness of spontaneous plants with different dispersal types was primarily affected by the connectivity of various surrounding patch types. Annual herbs showed a strong positive association with landscape fragmentation and the shape complexity of surrounding water patches, while perennial herbs were more closely related to the surrounding woodlands. We emphasize the importance of protecting and managing spontaneous plants based on species-specific, to establish a biodiversity-friendly and sustainable approach to urban green spaces construction.

Rapid global urbanization has resulted in increased biodiversity problems, particularly the loss of grounddwelling fauna in urban areas. Urban riparian corridors are an important green infrastructure for biodiversity conservation, in which urban vegetation plays an essential role. The influence of urban vegetation on grounddwelling faunal diversity is poorly understood. In this study, we used camera traps to collect the species, functional and phylogenetic diversity of ground -dwelling fauna in the Wenyu River -North Canal riparian corridor in Beijing, and analyzed the effects of the vegetation structure and plant community composition on the diversity and community composition of ground -dwelling animals. A plant -ground dwelling animal interaction network was also built to investigate the food supply of plants for ground -nesting animals. We found that at the vegetation structure level, the high connectivity within a radius of 2000 m and the homogeneous distribution within a radius of 1000 m of vegetation patches had generally positive effects on ground -dwelling animals, and shrublands exhibited a supportive role for mammals in riparian corridors. At the plant community level, tall herbs were instrumental in increasing the willingness of ground -dwelling animals to stay in and pass through the area. Native plants were the main plant food resource for ground -dwelling animals. Given the significant effects of vegetation on ground -dwelling fauna, we advocate that habitat conservation and food supply for ground dwelling animals be supported through appropriate plant landscape planning and design strategies in ecological corridors in urban areas in the future.

The fatigue property of the recycled mixture affects the structural design of recycled pavement. In order to explore the effect of different reclaimed asphalt pavement (RAP) content on the fatigue properties of recycled mixtures, the fatigue properties of recycled mixtures were analyzed through an indoor fatigue test and finite element numerical simulation. Based on the phenomenological method and the dissipated energy theory, the fatigue properties of recycled mixtures with different RAP contents were analyzed and the fatigue damage of the mixtures were also studies under various strain levels. Based on the finite element numerical model of fatigue damage, the stress distribution and internal damage field distribution of trabecular specimens under different temperatures, strain levels and RAP contents were analyzed. The results showed that the anti-fatigue level of the mixture decreased as the RAP content was increased. The relative change rate of dissipated energy for different types of mixtures showed a two-stage change rule with the change of load times, that is, the value is large and decreasing, and the value is small and stable. The correlation between the plateau value (PV) and the fatigue life was established under the double logarithm coordinates, which could better analyze the influence law of the RAP content on the fatigue performance of the recycled mixture. Under different temperatures, strain levels, and RAP contents, the stress at the bottom of trabecular specimen and the overall damage field were mainly generated at the upper part under compressive stress and the bottom under tensile stress, and the damage field distribution area accounted for a small part of the whole specimen. According to the test results and fatigue damage distribution, it is recommended that the content of recycled aggregate in recycled asphalt mixtures be less than 30% to ensure good performance. The research results have important practical significance for the improvement of fatigue performance and engineering application of recycled mixtures.

With the increasing urban environmental problems, spontaneous vegetation has been gradually emphasized for high ecological value, whose distribution has been reported as strongly influenced by fine-scale environmental factors. As one of the major zones for urban spontaneous vegetation distribution, urban riparian corridors are well suited for research on the response of spontaneous plants to microhabitats. Taking the Wenyu River-North Canal in Beijing as the study site, we measured six microhabitat factors, including the level of maintenance and visitor activity, canopy density, litter thickness, and distance to water and road, to investigate their effects on spontaneous plant assemblages. The results showed that spontaneous plants respond significantly to fine-scale habitat variation, and were more responsive to human disturbance than other factors. Compared with diversity indicators, the functional trait compositions were more significantly correlated with microhabitat factors. Under lower maintenance of plants, the spontaneous communities had a higher invasion risk for plants. Thick litter can impede the occurrence of invasive species while favoring the growth of native ones. Our findings are important for furthering understanding of the spontaneous plant community establishment, and can serve as a good reference for the maintenance and management of spontaneous plants in urban riparian corridors.

Urban biodiversity homogenization and native species habitat loss are becoming increasingly severe. The overuse of lawn grasses and cultivars in green spaces is one of the most important drivers. Scholars have asserted that spontaneous vegetation provides various ecological benefits and should be widely incorporated in planting design. Factors influencing spontaneous plant diversity have mainly been studied in specific habitats or at the city scale, and findings surrounding the attributes of urban parks that support the diversity of spontaneous plants are lacking. This study aimed to provide a perspective on conserving spontaneous plants through inferring the urban park attributes associated with plant diversity. Twenty-two urban park samples in Beijing were examined to identify the correlation between various park variables and spontaneous vegetation. This study recorded 199 spontaneous plant species, with large historic parks containing the most number of species. Park size was a remarkable predictive variable for the diversity of spontaneous plants. Species richness and diversity in large parks were significantly higher than in small parks; not only in total richness due to the species–area relationship but also in richness and diversity at the community level independent of plot number. Microhabitat heterogeneity and the percentage of green area had the strongest positive association with the richness of spontaneous plants. In contrast, the maintenance intensity, perimeter–area ratio, and fragmentation of green area, deciduous forest, and open lawn patches had negative associations with spontaneous plant richness. Redundancy analysis demonstrated that park area, maintenance intensity, microhabitat heterogeneity, and deciduous forest patches were the most remarkable variables predicting species composition. The correlations of variables related to water and open lawn patches with spontaneous plant diversity were more evident in summer. The predicted variables were also more significantly correlated with the diversity of exotic species in summer than in spring. Perennial herbs were more sensitive to the evaluated park attributes. This study elucidates how spontaneous plants are associated with the attributes of urban parks in Beijing, with critical implications for other large cities.

为科学准确地分析高速公路沥青路面使用性能的影响因素,保证高速公路的高效营运和科学养护.本文依托实际工况,详细分析了实际交通量、路面结构与材料、路面养护历史、温湿度状况及线形指标等因素对高等级公路路面性能的影响,然后基于层次分析法(AHP),将路面使用性能影响因素作为目标层建立层次结构,进行各影响因素的敏感性分析,最终得到高等级公路路面性能的影响因素敏感性排序,对高速公路科学养护决策具有重要指导意义.

[Objective] As a main component of coastal bird habitat, coastal green space is a strategic area for bird diversity conservation in China. Scientific habitat survey and assessment is not only the basis for bird diversity conservation in coastal green spaces, but also the premise for planning and design of ecological landscapes in urban coastal zones. This research is conducted in the context of urban biodiversity conservation and coastal zone construction, which aims to evaluate the bird diversity and habitat quality in the coastal green space in Dongdao Tsui, Yantai City by constructing a habitat suitability evaluation model,which may provide a reference for urban bird habitat construction and coastal ecological landscape planning and design.[Methods] This research takes the coastal green space in Dongdao Tsui, Yantai City, Shandong Province as the research area. Through field investigation, the research analyzes the characteristics of bird diversity. Meanwhile, the research adopts the correlation analysis and redundancy analysis（RDA） methods to explore the influence of 19 environmental factors on bird diversity at the microhabitat scale, which respectively represent the status of food source, shelter and interference. In addition, considering that the habitat suitability index（HSI） is most commonly used in habitat quality evaluation, the research combines the HSI method and the analytic hierarchy process（AHP） method to build an evaluation model for bird habitat suitability in the coastal green space in Dongdao Tsui.[Results] The research finds that there are a total of 61 species of birds are recorded in Dongdao Tsui, mostly classified under Passerines and Charadriformes. The research further analyzes the distribution characteristics of such birds and relevant environmental influencing factors, which may be summarized as follows. 1) The dense deciduous forest with a large area and continuous distribution has the highest bird diversity, while farmlands and impervious surfaces have fewer bird species. 2) There are mainly8 environmental factors influencing the distribution of bird diversity, including the coverage of trees, shrubs and herbs, etc. Specifically, the average height and the richness index of trees are significantly correlated with at least one index of bird diversity under different coastline distance gradients, and most of the significant influencing factors are related to tree structure. Compared with trees,the influence of herbs or shrubs on bird diversity is less significant. 3) The main factors influencing bird diversity are dissimilar at different distances from the coastline. As shown by the results of RDA, the average height of trees has the most significant influence on bird diversity in the offshore area, while the influence of plant factors on bird diversity is not significant in the land area 82 –135 m away from the coastline. In the land area more than 135 m away from the coastline, the richness index of trees has the most significant influence on bird diversity. Based on the above results, the research builds a habitat suitability evaluation model to evaluate bird habitat quality in Dongdao Tsui, and the evaluation results show that the habitat suitability of birds is lower in the offshore area and higher in the land area further away from the coastline, and less than half（45.71%） of the total area is evaluated as moderately suitable or above.[Conclusion] This research underlines that forests composed of deciduous trees can greatly support the diversity of birds in coastal green spaces as they can provide birds with abundant food and solid shelter against the strong breeze from the sea, which means that the conservation of forest vegetation is very important for constructing bird habitat in coastal green spaces. In addition,farmlands and grasslands, although not having the highest bird diversity, can still provide necessary habitat space for some special bird species, which can be improved by providing more abundant edible plants and small ponds.Although the tidal flat on the coastline fails to be fully explored in this research,considering the ecological sensitivity thereof, the research still suggests minimizing the intervention of and taking strict conservation measures for tidal flat. Furthermore, the habitat suitability evaluation model can effectively simulate the quality distribution of bird habitats, and is expected to be of practical guiding significance for the planning and design of the coastal green space in Dongdao Tsui. However, the research is limited at the micro-habitat scale and mainly focuses on the influence of plant community factors on bird diversity, without further revealing the influence of environmental factors of coastal green space on bird diversity at any other spatiotemporal scale. Additionally, other environmental factors such as climate and water and predation and competition between species should also be considered. In view of this, it is suggested that future researches investigate and analyze bird habitats in coastal green spaces at other spatiotemporal scales, and further explore the environmental factors influencing bird diversity and the distribution of typical bird guilds, which will be conducive to the building of a more comprehensive evaluation system for habitat suitability in coastal green spaces and the planning and design of ecological landscape in urban coastal zones.

Landscape change caused by ecological restoration projects in the karst rocky desertification area of southwestern China has presented ecological benefits, yet the visual aesthetic perception of the restored landscape has received less attention. Meanwhile, given the unpredictable worldwide health emergency caused by the COVID‐19 pandemic, it inspired us to be concerned about will citizens' aesthetic perceptions and attitudes to the change of restored landscape from pre‐COVID‐19 to during the outbreak of the COVID‐19 pandemic. Organizing an online survey, we explored citizens' visual aesthetic perceptions and attitudes to natural restored landscape (NRL) and managed restored landscape (MRL) on 757 citizens in Shilin Geopark (in Kunming, China), as well as how citizens' sociocultural backgrounds influence visual aesthetic preference. The results indicated that before the COVID‐19 pandemic, the professionals preferred NRL, while the nonprofessionals presented a higher preference for MRL. However, during the COVID‐19 pandemic, both two groups showed a higher preference for NRL, which implied that the experience of lockdown during the COVID‐19 pandemic might awaken most citizens' preference for the NRL. Among different kinds of restored plant communities, the landscape dominated by shrubs was the most popular. Furthermore, gender, age, career type, education, region, and citizens' visit frequency were significantly correlated with visual aesthetic perceptions before the COVID‐19 pandemic. During the COVID‐19 pandemic, professional background, gender, and age did not show significant impacts on visual aesthetic perceptions anymore. These results highlight the necessity of understanding visual aesthetic perceptions in different sociodemographic groups to encourage natural succession and create a nature‐based restored landscape in the karst area.

The rapid advancement of urbanization has led to serious damage to the ecological environment and a sharp decline in biodiversity.Although the areas of community parks are small,they have the largest number and great potential for protecting biodiversity.Spontaneous plants are not only an important part of plant diversity in the park,but also provide essential food sources and habitats for animals,therefore,their ecological values cannot be ignored.This paper focused on the community parks in Xicheng District of Beijing,based on the com-parative analysis of niche width,overlap index and plant diversity of spontaneous herbs,the community types of spontaneous herbs were explored to further clarify the community characteristics of spontaneous herbs in small-scale urban green space under the mode of intensive maintenance and management.The results were as fol-lows.(1)A total of 38 species of spontaneous herbs were recorded,belonging to 22 families and 36 genera.(2)Capsella bursa-pastoris,Chenopodium album,Solanum nigrum,Taraxacum mongolicum etc.had wide niche width;the niche overlap index(Oik)between the dominant species of spontaneous herbs ranged from 0 to 0.62.(3)In terms of plant diversity characteristics,the Patrick index and Shannon Wiener index of Yuetan Park were the highest,and the Pielou index of the Park in Nanlishi Road was the highest.(4)Using TWINSPAN classification method,the spontaneous herb communities were divided into 9 community types.V Chenopodium album+Capsella bursa-pastoris community accounted for the highest proportion.Finally,based on the ecological and landscape values,this paper put forward suggestions on the maintenance and management of spontaneous herbs in commu-nity parks to provide some references for building a near-natural and sustainable plant landscape.

为研究旧路不同层位沥青的老化规律,得到不同层位铣刨料混合使用时旧沥青的整体老化程度,进而确定再生混合料的应用层位,文章基于三大指标、四组分试验及红外光谱测试,分析了旧路面层不同层位的旧沥青分层老化规律,以此为基础确定了基于分层老化的旧沥青整体老化程度评价方法,并提出沥青老化程度分级标准,根据老化程度分级细化了再生混合料的应用层位推荐.研究成果为铣刨料的精准化利用提供了基础.

近30年来加剧的气候变化已经显著改变了北温带森林的树木物候,并对城市植被生态与景观产生长远影响.尽管此前已有研究揭示北京地带性植被生长季与花叶物候的整体变化趋势和气候响应特征,物候响应的种间差异及各物候阶段的响应敏感性仍有待进一步探究.聚焦1980s-2010s北京植物园45种园林树木物候的年代际变化,旨在揭示不同树种、各物候阶段的物候响应特征和响应敏感性差异.结果表明,与30年前相比,各树种始花期、盛花期和末花期分别平均提前10.2日、7.5日、2.4日(p<0.05),开花持续期延长,每日同步开花树种增多;各树种展叶始期平均提前7.8日(p<0.05),秋色盛期及落叶末期分别平均延后7日、7.8日(p<0.05),导致生长季及叶幕期显著延长(p<0.05).以物候变化量绝对值衡量特定物候阶段的响应敏感性,发现与其他物候阶段相比,始花期的响应敏感性最为突出且种间一致性较强,而叶衰老物候在响应方向及程度上的种间差异最为显著,开花、展叶物候的响应差异导致8个树种的花叶时序发生颠倒.以始花期、末花期、展叶始期及落叶末期的响应敏感性标准化值均值衡量各树种的综合物候敏感性并作树种聚类分析,发现玉兰、紫丁香、华北珍珠梅、元宝枫、黄刺玫等树种呈高物候敏感性,文冠果、毛泡桐、桑、碧桃、楸等树种呈低物候敏感性,且大部分树种各物候阶段的敏感性特征并不均衡,需予以持续关注和进一步探究.面对持续变暖、极端性增强的气候变化趋势,研究结果可从树种层面为提高北京城市植被景观与生态的气候适应性提供一定参考.

The loss of biodiversity due to rapid urbanization can be mitigated by urban riparian corridors. As an important component of urban biodiversity, spontaneous herbaceous plants play an essential role in the ecological functions of urban river corridors. Currently, the influence of the landscape structure within corridors on plant diversity has been poorly understood. In this study, we investigated the species and functional diversity, especially the functional traits of origin, pollination, and dispersal, of spontaneous herbaceous plants in the Wenyu River-North Canal riparian corridor in Beijing. The results showed that urban riparian corridors have a positive effect on the spread of alien and invasive plants as well as increasing the native plant diversity. No significant differences in diversity indicators but significant differences in the composition of functional traits between habitat types. Plants with long pollination and dispersal distances tended to be more closely related to the landscape structure indices at larger scales. Invasive plants were more common in patches with significant connectivity, while native plants were positively correlated with water and road connectivity. Anemophilous and anemochores were more common in habitats with sinuous edges. Ant-dispersed plants were closely related to the water bodies. Autochores were positively correlated with the connectivity of habitat patches. Plants dispersed by birds and mammals were weakly correlated with landscape structure. Our study underlines that emphasis should be placed on the support for plant pollination and dispersal, together with the prevention and control of invasive plants in the construction and management of future urban ecological corridors.

The service interaction platform for Jingdezhen cultural and creative products is the key material foundation and prerequisite for the design and development of Jingdezhen cultural and creative products. The application of virtual reality technology in the service interaction platform of cultural and creative products will bring good comprehensive effects and practical significance. This article focuses on the application of virtual reality technology in the Jingdezhen cultural and creative product service interaction platform, and launches relevant elaboration and analysis.

This paper presents an updated review of model-dependent regionalization methods in hydrology since the PUB decade, incorporating new regions and methodological advancements. Two categories of regionalization methods are discussed: distance-based and regression-based, with various modification approaches. Several factors affecting the accuracy of regionalization performance are identified, including hydrological models, climate characteristics, data availability, and regionalization techniques. The review concludes that distance-based regionalization methods with an output averaging option from multiple donor catchments are the most statistically reliable, and a threshold of 0.5–0.8 for donor selection is optimal for performance. The parsimonious hydrological model is also recommended, particularly in data-limited contexts. Other insights include the effectiveness of the ensemble concept and limited impact of prior classification. Additionally, it is found that the general performance difference between climatic classes is larger than between methods, and regression-based methods may have large uncertainties in tropical regions. Overall, this study provides practical guidance for improving regionalization studies and advancing the field of hydrology.

Bullous pemphigoid (BP) is an autoimmune blistering disease associated with anti-BP180 and anti-BP230 antibodies. The pathogenic action mechanism of immunoglobulin E (IgE) antibodies in BP has been studied since the 1970s, and IgE antibodies have gradually been confirmed as being important in BP; therefore, anti-IgE therapy may be a new option for the treatment of BP. Omalizumab, as an IgE monoclonal antibody, has been increasingly used clinically to treat BP in recent years. Here, we collected 35 papers investigating omalizumab for BP treatment in a total of 83 patients, and the vast majority of patients showed varying degrees of improvement after treatment, except for a small number of patients with poor clinical outcomes. The patients were then divided into three groups according to dosing frequency and number of doses. Statistical analysis indicated that dosing frequency had little effect on clinical efficacy. While the groups with different numbers of doses were evaluated, the results concluded that clinical efficacy was affected by the number of doses, but there was no positive correlation between the number of doses and clinical efficacy.

近年来,由水稳基层膨胀引起的沥青路面隆起现象在我国新疆、内蒙古等地频繁出现,沥青路面隆起高度可达3～5 cm,严重影响了道路寿命和行车安全,且维修难度大.因此,对比论证了在保证路面不发生膨胀隆起破坏时原材料、水稳基层混合料和环境中的硫酸盐含量阈值范围,得到了荒漠区高速公路路基土硫酸盐含量侵蚀等级划分标准,并根据实际工程经验、试验结果和理论研究,从材料、道路结构和施工工艺3个方面提出了基于设防分级的抗膨胀技术措施.该研究成果可为国内类似地区水稳基层膨胀的预防设计和处治提供参考.

In order to solve the problems of difficult compaction and poor durability of ultrathin overlays, the performance of easy-compaction and high-durability (ECHD) modified asphalt and mixtures were studied. Taking matrix asphalt and SBS modified asphalt as the control group, the high- and low-temperature rheological properties of the asphalt were analysed by MSCR and BBR. The asphalt samples were observed and analysed by fluorescence microscope and infrared spectrometer, and the road performance, compaction performance and surface functional durability of the asphalt mixture were tested. The results show that the ECHD asphalt has the best high- and low-temperature properties. The modifier particles are uniformly dispersed in the asphalt, which can form a dense network structure and a stable system. The ECHD asphalt mixture has good low temperature and water stability, and the high-temperature stability is slightly lower than that of the SBS-modified asphalt mixture, but meets the requirements of the specification. It has the smallest compaction energy index CEI, and the largest compaction rate K. Before and after wearing 30,000 times, the asphalt mixture has the best wear resistance and surface texture, and the surface functional durability is the best. This paper provides a reference for material selection of ultrathin overlays.