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Articles 961 - 990 of 5898

Full-Text Articles in Transportation Engineering

Study On Health State Evaluation Method Of Highway Tunnel Based On Neutrosophic Theory, Deng Fayou, Xia Caichu, Xu Chongbang May 2023

Study On Health State Evaluation Method Of Highway Tunnel Based On Neutrosophic Theory, Deng Fayou, Xia Caichu, Xu Chongbang

Journal of China & Foreign Highway

The structural complexity and inherent uncertainties of highway tunnels necessitate comprehensive consideration of various uncertain factors to reasonably evaluate their health state. By introducing neutrosophic theory, which accounts for structural uncertainties, this paper proposes a health state evaluation method for highway tunnels based on neutrosophic cosine and tangent similarity measures. The proposed method was applied to evaluate the health state of 10 samples. A comparison between the actual evaluation grades and the results obtained using the proposed method shows that the evaluation results are consistent with the actual grades. This indicates that the proposed method effectively addresses uncertainties in the …

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Interlayer Bonding Performance Of Wtr/Apao Composite Modified Asphalt, Ji Hongyan, Yan Kezhen, Yuan Jian, Zhang Xuanyu May 2023

Interlayer Bonding Performance Of Wtr/Apao Composite Modified Asphalt, Ji Hongyan, Yan Kezhen, Yuan Jian, Zhang Xuanyu

Journal of China & Foreign Highway

To investigate the bonding performance of waste tire rubber (WTR)/ amorphous α-olefin copolymer (APAO) composite modified asphalt as a waterproof bonding layer in asphalt pavements on cement concrete bridges, shear and pull-off tests were conducted. The shear strength and pull-off strength of SBS-modified asphalt, WTR-modified asphalt, and WTR/APAO composite modified asphalt were compared under different application rates and temperatures. The results show that WTR/APAO composite modified asphalt exhibits the best bonding performance, followed by WTR-modified asphalt, with SBS-modified asphalt performing the worst. Based on the shear and pull-off strengths at different temperatures, the optimal application rates were determined as 1.7 …

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Optimization Study On Indoor Vibratory Compaction Curves Of Cement Stabilized Macadam, Qiu Youqiang, Zhang Liujun May 2023

Optimization Study On Indoor Vibratory Compaction Curves Of Cement Stabilized Macadam, Qiu Youqiang, Zhang Liujun

Journal of China & Foreign Highway

To obtain well-defined secondary convex vibratory compaction curves and reduce the need for supplemental compaction point tests, this paper uses vibratory compaction tests for cement stabilized macadam in laboratory settings. Tests were conducted for two pavement sections along National Highway 110 (Hohhot to Bikeqi), exploring the influence of predefined moisture content intervals on vibratory compaction curves under varying cement dosages. The vibratory compaction curves were also compared with heavy compaction curves for analysis. The results show that the vibratory compaction curve is significantly influenced by the predefined moisture content intervals and cement dosage. For a moisture content interval of 1%, …

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Study On Treatment Of Karst Foundation By Dynamic Compaction, Lyu Jiang, Zhao Hui, Yang Biao May 2023

Study On Treatment Of Karst Foundation By Dynamic Compaction, Lyu Jiang, Zhao Hui, Yang Biao

Journal of China & Foreign Highway

Dynamic compaction is a commonly used method for treating karst foundations with cavities; however, the design parameters of dynamic compaction under different working conditions lack clear standards. This paper employs the finite element software Abaqus to simulate the effects of surrounding rock quality and karst roof thickness on the stability of karst cave roofs during dynamic compaction treatment. The results indicate that the vertical displacement and maximum tensile stress of karst cave roofs are negatively correlated with roof thickness. For Grade II and III surrounding rocks with better properties, no cave collapse occurred after dynamic compaction treatment. In contrast, for …

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Research On Road Crack Recognition Model Based On Yolo V3 Deep Learning Algorithm, Su Weiguo, Wang Jingxiao May 2023

Research On Road Crack Recognition Model Based On Yolo V3 Deep Learning Algorithm, Su Weiguo, Wang Jingxiao

Journal of China & Foreign Highway

To address the challenges of manual intervention in road crack detection and the inaccuracy of traditional recognition algorithms, this paper proposes a road crack recognition method based on the YOLO v3 deep learning algorithm. The dataset images were first resized to 416×416 pixels. Labelme was then used to annotate cracks in the images and convert the boundary box location information. Finally, the YOLO v3 algorithm framework was employed for model training. The results show that the YOLO v3 algorithm achieves precision, recall, and F1 scores above 95%, with an image detection speed of 0.123 seconds per image. The YOLO v3 …

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Discussion On Formula Of Off‐Load Increase Coefficient Of Single‐Box Multi‐Cell Wide Girder, Gao Qingfei, Wang Renzhi, Li Jun, Guo Binqiang, Qin Weijun May 2023

Discussion On Formula Of Off‐Load Increase Coefficient Of Single‐Box Multi‐Cell Wide Girder, Gao Qingfei, Wang Renzhi, Li Jun, Guo Binqiang, Qin Weijun

Journal of China & Foreign Highway

Single-box multi-cell wide girders are widely applied in highway and urban bridges due to their excellent integrity and large width, especially with increasing traffic volumes. However, existing methods for calculating the off-load increase coefficient of single-box multi-cell wide girders are either too complex or fail to meet engineering needs, limiting their applicability in preliminary design. This paper explores eight influencing factors of the off-load increase coefficient, calculates the coefficients using the transverse frame method, and proposes an empirical formula for the off-load increase coefficient. The proposed formula is validated using the Xiushui Street Wide Girder Bridge in Jilin City.

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Study On Modification Of Phosphate Pretreated Aggregate Vegetation Porous Concrete, Li Zhengxing, Hou Zebiao May 2023

Study On Modification Of Phosphate Pretreated Aggregate Vegetation Porous Concrete, Li Zhengxing, Hou Zebiao

Journal of China & Foreign Highway

To enhance the interfacial structure between aggregates and cementitious materials in vegetation porous concrete and improve its compressive strength, this paper investigates the effects of phosphate pretreatment on aggregate properties and the corresponding compressive strength of vegetation porous concrete. The performance of untreated aggregates, water-washed aggregates, and acid-treated aggregates was evaluated, and the modification mechanism was explored from the perspective of the interfacial transition zone (ITZ) using scanning electron microscopy (SEM). The results show that phosphate effectively removes impurities from the aggregate surface and increases surface roughness, thus improving the compactness and stability of the ITZ. After soaking the aggregates …

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Experimental Study On Water Stability Of Sand Compound Modified Mud Road, Chai Ruixiang, Wu Kai, Ye Wei, Cui Jinmei, Wang Jicheng, Li Zhantao May 2023

Experimental Study On Water Stability Of Sand Compound Modified Mud Road, Chai Ruixiang, Wu Kai, Ye Wei, Cui Jinmei, Wang Jicheng, Li Zhantao

Journal of China & Foreign Highway

Sand compound modified mud, as a coupled medium of sand and soil, differs from traditional modified mud. To further investigate its water stability indicators, orthogonal design was employed to conduct indoor water stability simulation tests (surface infiltration test, underground capillary water test, and dry-wet cycle test) on sand compound modified mud. The water stability of the modified mud was characterized using the change rate of unconfined compressive strength (UCS). The results show that the unconfined compressive strength and water stability of the modified mud were significantly improved. Under different water disturbance conditions, the order of influence of factors such as …

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Deformation Monitoring Of Highway Subgrade In Alpine Area Based On Spaceborne Insar, Luo Boren, Yu Fei, Yu Shaohuai May 2023

Deformation Monitoring Of Highway Subgrade In Alpine Area Based On Spaceborne Insar, Luo Boren, Yu Fei, Yu Shaohuai

Journal of China & Foreign Highway

The harsh geological and climatic conditions in the high-altitude alpine regions of Northwest China, including the widespread distribution of seasonal permafrost and other unfavorable geological bodies, significantly affect the service life of highways and threaten driving safety. Traditional highway deformation monitoring methods are inefficient, limited in coverage, and provide incomplete deformation information. This study employs spaceborne InSAR technology for highway deformation monitoring, enabling large-scale extraction of deformation information along highway corridors. The findings reveal the deformation patterns of highway subgrades in permafrost regions, offering fundamental data for targeted remediation of hazardous highway sections. This approach ensures the scientific construction and …

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Research On Compaction Control Method Of High Water Content And High Liquid Limit Clay In Guizhou Province, Xu Shuliang May 2023

Research On Compaction Control Method Of High Water Content And High Liquid Limit Clay In Guizhou Province, Xu Shuliang

Journal of China & Foreign Highway

To study and verify the compaction control method for high liquid limit clay subgrade in the humid and rainy regions of Guizhou Province, a series of experiments were conducted on high water content and high liquid limit clay from the Kaiyang Expressway (Kaili to Yangjia) in Guizhou. The experiments included wet heavy compaction tests, CBR strength tests, basic physical property tests, consolidation tests, thermogravimetric analysis, and trial road tests to analyze the performance of high liquid limit clay in road applications. The results show that for high liquid limit clay, increasing compaction energy does not always improve performance, as excessive …

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Study On Dynamic Resilience Modulus Prediction Model Of Subgrade Fine‐Grained Soil Based On Physical Property Parameters, Tan Wei May 2023

Study On Dynamic Resilience Modulus Prediction Model Of Subgrade Fine‐Grained Soil Based On Physical Property Parameters, Tan Wei

Journal of China & Foreign Highway

This paper investigates representative fine-grained subgrade soils from a highway project. Samples with varying water content and compaction degrees were prepared, and the effects of water content, compaction degree, plasticity index, dynamic deviator stress, and confining pressure on the dynamic resilience modulus (Mr) were analyzed using dynamic triaxial tests. Matlab’s global optimization toolbox was employed to identify the relationships between model parameters ki and physical property indices, thus constructing a prediction model for the dynamic resilience modulus based on physical properties. The predictive performance of this model was compared with conventional models outlined in existing standards. The results show that …

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Study On Failure Mechanism Of Rainfall Slope Based On Full‐Scale Slope Model Experiment, Zhang Yongchuang May 2023

Study On Failure Mechanism Of Rainfall Slope Based On Full‐Scale Slope Model Experiment, Zhang Yongchuang

Journal of China & Foreign Highway

Field investigations in debris flow source areas reveal that granite is exposed on slope surfaces, while a thin layer of sandy, weathered residual soil is distributed at the slope tops. This paper focuses on the significant permeability differences between the slope base and the upper weathered soil layer. A full-scale slope model experiment was conducted to replicate these characteristics, including rainfall infiltration simulations under both exposed surface conditions and conditions with non-woven fabric filter mats applied. The aim was to investigate the failure mechanism of rainfall-induced debris flows. The results show that the primary trigger for debris flows is the …

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Detection Method Of Rural Road Pavement Damage Based On Smart Phone, Zhang Yang, He Li, Tang Qingzhou, Zhang Dejin May 2023

Detection Method Of Rural Road Pavement Damage Based On Smart Phone, Zhang Yang, He Li, Tang Qingzhou, Zhang Dejin

Journal of China & Foreign Highway

Automatic detection of rural road pavement damage is a critical prerequisite for scientific maintenance. To address issues such as high false detection rates, missed detection, and the inability to quantify damage when using smartphones for pavement damage detection, this paper proposes a novel detection method. The proposed method involves using a smartphone to capture pavement images. A region of interest is first selected in the image, followed by weighted least-squares filtering, Canny edge detection, and Hough transform line detection to identify the pavement, minimizing environmental interference and reducing false detection rates. Perspective transformation is then applied to the pavement region …

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Analysis Of Socket Depth Between Bridge Pier And Cap With Improved Socket Connection, Ge Jiping, Lai Luqi, Wang Zhigang May 2023

Analysis Of Socket Depth Between Bridge Pier And Cap With Improved Socket Connection, Ge Jiping, Lai Luqi, Wang Zhigang

Journal of China & Foreign Highway

Traditional prefabricated socket-type bridge piers are limited in engineering applications due to the requirement for deep socket connections. This paper proposes an improved socket connection design incorporating measures such as side shear keys, U-shaped anti-punching reinforcement at the pier base, high-strength non-shrink grouting materials, and large-diameter corrugated metal pipe constraints. The current formulas for calculating socket depth in socket-type connections are reviewed, and a modified calculation formula for improved socket-type piers is presented. The influence of factors such as axial compression ratio and concrete strength on socket depth is discussed. The analysis shows that the improved socket connection reduces socket …

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Finite Element Model Updating Of Long Span Suspension Bridge Based On Optimized Radial Basis Function Neural Network, Yang Wenfu, Chen Xin May 2023

Finite Element Model Updating Of Long Span Suspension Bridge Based On Optimized Radial Basis Function Neural Network, Yang Wenfu, Chen Xin

Journal of China & Foreign Highway

To achieve accurate prediction and analysis of the structural behavior of long-span suspension bridges, a finite element model updating method is proposed. An optimized radial basis function neural network (RBFNN) is constructed using a genetic algorithm to map the relationship between structural responses and parameters. Using structural dynamic responses as inputs, the model updating was performed on a long-span suspension bridge using both numerical simulation data and actual data from a health monitoring system. The results show that the optimized RBFNN effectively represents the functional relationship between structural responses and parameters to be updated. Model updating via the optimized RBFNN …

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Key Technology For Design Of Composition Section Of Hybrid Girder Cable‐Stayed Bridge, Tian Bo, Song Lubing May 2023

Key Technology For Design Of Composition Section Of Hybrid Girder Cable‐Stayed Bridge, Tian Bo, Song Lubing

Journal of China & Foreign Highway

The main bridge of the Yibin Nanxi (Xianyuan) Yangtze River Bridge adopts an asymmetric hybrid girder cable-stayed design with a 572 m main span. The main span and the north-side span utilize hybrid girders, while the south-side span uses a concrete girder. A steel-concrete composite section is introduced between the south-side span and the main span. This paper explores multiple schemes for the location and key structural design of the steel-concrete composite section, prioritizing a full-section rib connection with a pressure-bearing shear transfer transition structure. The structural rationality and construction feasibility were verified through on-site static model tests, failure model …

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Analysis And Reinforcement Measures For Unconventional Cracks In Gravity U‐Type Abutment, Cheng Kun, Du Yinguang, Liu Zhang May 2023

Analysis And Reinforcement Measures For Unconventional Cracks In Gravity U‐Type Abutment, Cheng Kun, Du Yinguang, Liu Zhang

Journal of China & Foreign Highway

Horizontal cracking at the foundation level is uncommon in gravity U-type abutments. This paper investigates the causes and reinforcement measures for unconventional horizontal cracks in the foundation and vertical cracks in the abutment wall of a gravity U-type abutment on a highway bridge. Survey and analysis results show that the vertical cracks in the abutment wall are structural cracks caused by excessive reaction forces from permanent loads combined with the impact loads from vehicles at expansion joints. The horizontal foundation cracks result from the presence of filler interlayers at the foundation, which softened over time due to water exposure, leading …

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Analysis On Vehicle‐Bridge Interaction Of High‐Pier Continuous Rigid Frame Bridge, Liu Huaquan, Yang Dehai, Cai Chengqi, Huang Zhenming, Chen Zhouqi May 2023

Analysis On Vehicle‐Bridge Interaction Of High‐Pier Continuous Rigid Frame Bridge, Liu Huaquan, Yang Dehai, Cai Chengqi, Huang Zhenming, Chen Zhouqi

Journal of China & Foreign Highway

To study the dynamic response characteristics of the vehicle-bridge system under moving vehicle loads, a three-span high-pier continuous rigid frame bridge was selected as the research object. A 2-axle, 7-degree-of-freedom vehicle model was applied to explore the effects of vehicle speed, number of vehicles, and vehicle load on the dynamic response of the vehicle-bridge system. The results show that vehicle speed has minimal impact on the peak displacement response of the bridge. However, when vehicles travel at the same speed, the peak displacement response differs across bridge spans, with resonance occurring at a vehicle speed of 40 km/h. As the …

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Research On Application Of Equivalent Stiffened Plate Elements In Local Stability Calculation Of U‐Shaped Stiffened Plates, Chen Xiangjun May 2023

Research On Application Of Equivalent Stiffened Plate Elements In Local Stability Calculation Of U‐Shaped Stiffened Plates, Chen Xiangjun

Journal of China & Foreign Highway

To address the issue of excessively large computational models in the numerical simulation of U-shaped stiffened plates in large-span flat steel box girder main girders, this paper proposes a finite element calculation theory using equivalent stiffened plate elements and a simplified method for U-shaped stiffened plates. By simplifying the U-shaped small box ribs in U-shaped stiffened plates into equivalent stiffening strips, the transverse stiffness of the cover plate is redistributed, and the effect of equivalent stiffeners on the stress of the plates is calculated. Stability analysis was conducted using Fortran language developed on the Ansys platform, and the results were …

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Optimization Research Of Laying Method And Material Type Selection Of Thermal Insulation Layer For Tunnels In Cold Region, Wu Tao, Liu Zhichun, Liu Xuejiao, Zhang Hongfei May 2023

Optimization Research Of Laying Method And Material Type Selection Of Thermal Insulation Layer For Tunnels In Cold Region, Wu Tao, Liu Zhichun, Liu Xuejiao, Zhang Hongfei

Journal of China & Foreign Highway

To address the issue of frost damage in tunnels in cold regions, research on thermal insulation and frost prevention is crucial. This paper utilizes an improved analytic hierarchy process combined with grey relational analysis to identify optimal insulation materials suitable for different laying methods that provide effective insulation. Numerical simulation methods were then used to calculate and analyze the tunnel temperature field under various combinations of insulation materials and laying methods. Based on the “composite temperature field” comparison results, the optimal insulation scheme was determined. The results show that the “off-wall laying + Furritek insulation board” combination is the optimal …

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Experimental Study On Influence Of Phosphorus Slag Powder On Pervious Concrete, Lou Jianxin, Yang Jianyong, Zhang Yuxian, Li Jun, Wang Jie, Liu Jian May 2023

Experimental Study On Influence Of Phosphorus Slag Powder On Pervious Concrete, Lou Jianxin, Yang Jianyong, Zhang Yuxian, Li Jun, Wang Jie, Liu Jian

Journal of China & Foreign Highway

This paper investigates the effects of replacing cement with phosphorus slag powder on the mechanical properties, permeability, and pavement performance of pervious concrete. The results show that incorporating a certain amount of phosphorus slag powder as a partial replacement for cement in pervious concrete is feasible. When the replacement ratio of phosphorus slag powder is within 10%, it enhances the strength of pervious concrete. The optimal replacement ratio of phosphorus slag powder is 8%, achieving a compressive strength of 24.18 MPa, a void ratio of 15.37%, and a permeability coefficient of 2.45 mm/s, which meet the requirements for fully permeable …

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Dynamic Load Response Analysis Of Rubber Powder Modified Asphalt Mixture, Yang Sanqiang, Sun Shuang, Li Qian, Liu Xinlei, Qin Lusheng May 2023

Dynamic Load Response Analysis Of Rubber Powder Modified Asphalt Mixture, Yang Sanqiang, Sun Shuang, Li Qian, Liu Xinlei, Qin Lusheng

Journal of China & Foreign Highway

To investigate the mechanical response of rubber powder modified asphalt pavement under dynamic loads, this paper, based on the “Full-Scale Accelerated Pavement Loading Testing” project, designed experimental schemes for asphalt mixtures with varying rubber powder contents. The paper employed accelerated loading test equipment to evaluate the stress and deformation of pavement structures, obtaining dynamic strain response data to analyze the strain response patterns of various structural layers. Combining finite element numerical simulations and a custom loading program, the paper examined the dynamic responses of rubber powder modified asphalt pavements under variable temperature conditions. The results show that through microscopic testing, …

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Aging Asphalt Concrete Cracking Performance Under Different Cyclic Loading Frequencies, Yan Jingchen, Ma Yanpei, Yan Junjie May 2023

Aging Asphalt Concrete Cracking Performance Under Different Cyclic Loading Frequencies, Yan Jingchen, Ma Yanpei, Yan Junjie

Journal of China & Foreign Highway

Using digital speckle technology, this paper examines the crack propagation behavior of asphalt concrete under repeated loading, analyzing the crack propagation mechanism from macro- and micro-perspectives under different aging conditions and loading frequencies for four types of asphalt concrete. The results show that the basalt fiber-reinforced asphalt concrete beam specimens delay the onset of the unstable crack propagation phase, thus extending the service life of the asphalt concrete. Aging accelerates the progression of asphalt concrete to the unstable crack propagation point, advancing this stage by 4%-5%. Under repeated loading frequencies of 5 Hz, 10 Hz, and 15 Hz, the damage …

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Design And Development Of Two And Three Dimensional Integration System For Highway Based On Webgis, Che Defu, Zhou Huajun May 2023

Design And Development Of Two And Three Dimensional Integration System For Highway Based On Webgis, Che Defu, Zhou Huajun

Journal of China & Foreign Highway

To address the inefficiencies, lengthy cycles, and high resource demands in the process of determining the annual project database for highway maintenance quotas in Liaoning Province, a 2D and 3D integration system for highways based on WebGIS was designed and developed. This system not only provides a macroscopic view of the geographic distribution and overall characteristics of highways but also offers a detailed and intuitive representation of the spatial relationships and conditions of roadbeds and pavement damage. The system meets the needs of modern highway management and can serve as a reference for other highway maintenance quota tasks.

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Study On Relationship Of Solar Radiation Temperature And Pier‐Top Displacement Of Ultra‐High Thin‐Walled Hollow Pier, Liu Zhishen, Zhang Yifei, Song Fei, Su Jufeng, Ren Xiang May 2023

Study On Relationship Of Solar Radiation Temperature And Pier‐Top Displacement Of Ultra‐High Thin‐Walled Hollow Pier, Liu Zhishen, Zhang Yifei, Song Fei, Su Jufeng, Ren Xiang

Journal of China & Foreign Highway

Thin-walled hollow piers are widely used in high-pier and long-span continuous rigid-frame bridges. Solar radiation-induced displacements at the tops of ultra-high thin-walled hollow piers can negatively affect the structural alignment and stress during construction and post-construction phases. Based on a 180 m high thin-walled hollow pier of a large bridge in Shaanxi Province, this paper analyzes the temperature field and pier-top displacement using data collected during two 24-hour periods: August 28-29 and October 11-12. The temperature field and pier-top displacement patterns over time were studied using finite element analysis. The results show that the temperature difference between the north and …

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Model Test Study On Mechanical Characteristics Of Spherical Joints In Multi‐Point Support Swivel System, Zeng Lifei May 2023

Model Test Study On Mechanical Characteristics Of Spherical Joints In Multi‐Point Support Swivel System, Zeng Lifei

Journal of China & Foreign Highway

As a critical load-bearing component in bridge swivel systems, the mechanical behavior of spherical joints is essential for the safety of bridge swiveling operations. This study focuses on the spherical joints of a multi-point support swivel system for the bridge over the Xiangyang North Marshalling Yard. Model tests were conducted to analyze the effects of the number of supporting legs, swivel speed, track smoothness, and wind load on the stress of spherical joints. The stress variation patterns of spherical joints under different working conditions were investigated. The results show that increasing the number of supporting legs improves the uniformity of …

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Selection Of Phase Change Materials For Asphalt Pavement Based On Molecular Dynamics Simulation, Liu Fujun, Tian Xin, Liang Meichen, Guo Meng May 2023

Selection Of Phase Change Materials For Asphalt Pavement Based On Molecular Dynamics Simulation, Liu Fujun, Tian Xin, Liang Meichen, Guo Meng

Journal of China & Foreign Highway

Phase change materials (PCMs) have significant application potential in temperature regulation for asphalt pavements. To select suitable PCMs for road applications, this paper utilizes molecular dynamics simulation to analyze the molecular behaviors of lauric acid and polyethylene glycol (PEG). Experimental studies were conducted to validate the simulation results. The results show that molecular dynamics simulation provides an efficient and convenient method for comparing the performance of PCMs. PEG outperforms lauric acid in terms of molecular density, cohesive energy density, solubility parameters, and thermal conductivity, making it more suitable as a phase change material for asphalt pavements.

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Study On Alkali Excitation Mechanism Of Large Dosage Slag Fine Powder, Mei Yang May 2023

Study On Alkali Excitation Mechanism Of Large Dosage Slag Fine Powder, Mei Yang

Journal of China & Foreign Highway

To reveal the alkali excitation mechanism of high-dosage slag, this paper combines a three-factor, three-level orthogonal design with macro- and micro-performance tests and microstructure analysis. The effects of different activators, including Ca(OH)2, Na2SiO3, Na2SO4, and CaSO4, in single and dual combinations on the initial and final setting times, pore solution pH, and strength of concrete were explored. The results show that the impact on the strength of hardened paste of composite cementitious materials is ranked as: activator type > dosage > dual-mix ratio. The optimal dual-mix dosage is 4%, with the best combination being Ca(OH)2 and Na2SiO3 at a ratio of 5:1. …

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Study On Microstructure Of Asphalt Modified By Oil‐Coal Blend, Guo Pengfei, Zhou Xinfeng May 2023

Study On Microstructure Of Asphalt Modified By Oil‐Coal Blend, Guo Pengfei, Zhou Xinfeng

Journal of China & Foreign Highway

To investigate the microstructure and modification mechanism of asphalt modified with oil-coal blend, SK-90# asphalt was mixed with 5%, 10%, 15%, 20%, and 25% (external blending method) oil-coal blend to produce modified asphalt. The performance and microstructural changes of the modified asphalt were analyzed using contact angle testing, infrared spectroscopy, cross-sectional SEM, and X-ray photoelectron spectroscopy. The results show that the oil-coal blend exhibits good compatibility with asphalt. During the modification process, esterification reactions occurred, resulting in a decrease in hydroxyl-containing aromatic compounds and an increase in carbonyl-containing aromatic compounds. Macroscopically, the oil-coal blend-modified asphalt demonstrated excellent high-temperature performance.

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Analysis Of Expressway Routine Maintenance Performance Management Based On Dea, Li Yuhuan, Shi Xiaoli, Gao Nan May 2023

Analysis Of Expressway Routine Maintenance Performance Management Based On Dea, Li Yuhuan, Shi Xiaoli, Gao Nan

Journal of China & Foreign Highway

To allocate maintenance resources efficiently and improve management levels, this paper examines the maintenance performance and improvement strategies of routine maintenance projects for 23 expressways in Shaanxi Province using 2018 operational maintenance data and data envelopment analysis. The results show that for some inefficient subsidiaries, traditional radial- and slack-based performance improvement methods are challenging and impractical in the short term. Therefore, a scenario-dependent model-based long-term incremental improvement strategy is proposed. By leveraging relative improvement values, this strategy enables phased improvements for inefficient subsidiaries. It provides a feasible approach for subsidiaries to set lower short-term performance improvement targets while achieving gradual …

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