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2023

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Full-Text Articles in Other Civil and Environmental Engineering

Study On Frost Resistance And Pore Structure Of Nano-Sio 2 Modified Pavement Concrete Under Fatigue Load, Zhou Xuexiang, Zheng Wenshi, Wu Cong Sep 2023

Study On Frost Resistance And Pore Structure Of Nano-Sio 2 Modified Pavement Concrete Under Fatigue Load, Zhou Xuexiang, Zheng Wenshi, Wu Cong

Journal of China & Foreign Highway

To improve the frost resistance of concrete pavement under fatigue load, this paper simulated the freeze-thaw damage of concrete pavement under vehicle load by indoor fatigue loading and alternating freeze-thaw cycling test. Meanwhile, it designed the bending tensile test to test the residual bending tensile strength of nano SiO2-modified pavement concrete after freezing and thawing, and adopted the mercury injection method to test the microscopic pore structures of concrete. Additionally, by employing the electron microscope, the change rules of pores in the concrete under the action of fatigue load were observed, and the effect of nano SiO2 dosage, the number …


Influence Of Natural Environment On The Serviceability Of Emulsified Asphalt Cold Recycled Mixture, Yang Puxin Sep 2023

Influence Of Natural Environment On The Serviceability Of Emulsified Asphalt Cold Recycled Mixture, Yang Puxin

Journal of China & Foreign Highway

To improve the early serviceability of emulsified asphalt cold recycled mixtures, this paper studied the effect of curing conditions on the mechanical strength and stability of emulsified asphalt cold recycled mixtures by conducting indoor tests. The results show that in the same test conditions, the indoor emulsified asphalt cold recycled mixture can better characterize the serviceability of practical projects. Compared to the indoor specimen mixture, the stability and cleavage strength of field mixture core samples are increased by an average of 5.5% and 10.7% respectively. Under the curing time of no less than 7 d, the stability, cleavage strength and …


Experimental Study On Recycled Brick Powder Foam Concrete Based On Slurry Substitution Method, Liao Shixian, Huang Lei Sep 2023

Experimental Study On Recycled Brick Powder Foam Concrete Based On Slurry Substitution Method, Liao Shixian, Huang Lei

Journal of China & Foreign Highway

Foam concrete is a kind of porous lightweight building material characterized by sound insulation and noise reduction, heat insulation and fire resistance, heat preservation and frost resistance. However, it has defects such as low strength, high porosity and poor integrity, thus limiting its wide application in the field of building materials. Recycled brick powder can be prepared from construction waste of clay bricks and has certain volcanic ash activity. Meanwhile, the mechanical properties of foam concrete can be improved by employing waste bricks as an admixture in cement-based composite materials. In view of the problems of the cement substitution method, …


Study On Mix Design And Performance Of Permeable Concrete Considering Sand Ratio And Aggregate To Binder Ratio, Wei Yazhou, Ji Rongqing Sep 2023

Study On Mix Design And Performance Of Permeable Concrete Considering Sand Ratio And Aggregate To Binder Ratio, Wei Yazhou, Ji Rongqing

Journal of China & Foreign Highway

Considering the effect of the sand ratio and aggregate to binder ratio, this paper improved the traditional mix ratio design method-volumetric method, and investigated the influence of the sand ratio, aggregate to binder ratio, and maintenance method on the mechanical properties and permeability coefficient of pervious concrete based on the improved method. The results show that under the sand ratio of 15%, the compressive strength of concrete is significantly increased and the permeability is not affected. When the aggregate to binder ratio is 3.0‒3.1, the compressive strength and permeability coefficient of the concrete can be both considered. Additionally, compared to …


Experimental Study On Mechanical Properties Of Steel-Polypropylene Mixed Fiber Rubber Concrete, Qiu Jiandong Sep 2023

Experimental Study On Mechanical Properties Of Steel-Polypropylene Mixed Fiber Rubber Concrete, Qiu Jiandong

Journal of China & Foreign Highway

Waste rubber materials can be recycled to obtain rubber aggregates, which can be employed in cement concrete products. This paper carried out mechanical performance tests on ordinary concrete and rubber concrete (rubber substitution rate of 20%) with different fiber combinations (doped MS, co-doped PP, and mixed MS-PP), and mainly examined the slump, density, compressive strength, modulus of elasticity, split tensile strength, and rupture strength of the concrete. The results show that the relevant performance indexes decrease significantly after 20% of rubber aggregate is added to the concrete. However, the mechanical performance of ordinary concrete and rubber concrete with the combination …


Application Of Bim Forward Design In Complex Three-Dimensional Traffic Design Stage, Wang Bo, Zhu Xinghu, Pei Wangjian, Ge Puta Sep 2023

Application Of Bim Forward Design In Complex Three-Dimensional Traffic Design Stage, Wang Bo, Zhu Xinghu, Pei Wangjian, Ge Puta

Journal of China & Foreign Highway

To improve the accuracy and efficiency of complex three-dimensional traffic design, and provide basic digital data for the whole life cycle, this paper researched and investigated the application of BIM technology in the complex three-dimensional traffic design stage by taking the convergence project of the Qianhai section of Shenzhen Coastal Expressway and Nanping Expressway in Guangdong as a case study. Meanwhile, it put forward the BIM forward design schemes for the fields of roads, bridges, and tunnels, carried out secondary development, and built the three-dimensional parametric model, with the design results optimized. Additionally, design analysis and application were conducted to …


Research On Interchange Reconstruction Design Of Minxiao Hub, Hu Tian, Tan Ximing, Yi Xuebin, Wei Hui Sep 2023

Research On Interchange Reconstruction Design Of Minxiao Hub, Hu Tian, Tan Ximing, Yi Xuebin, Wei Hui

Journal of China & Foreign Highway

Based on the design of the Minxiao hub interchange, this paper analyzed the technical problems of frequent traffic accidents after the initial reconstruction of Minxiao hub interchange, and put forward corresponding reconstruction suggestions. In the interchange design details, the design points about the dual lanes adopting single lanes and speed change lanes only put forward the distance requirement of 60 m for the transition sections, but whether the gradual changes of the travel lanes and hard shoulders are completed in the same road section or not is not clarified. The initial reconstruction of Minxiao hub interchange is designed to complete …


Exploring Long-Term Protective Effect Of High Vertical Sand Barrier On Top Of Complex Longitudinal Sand Ridge In Taklamakan Desert, Jin Changning Sep 2023

Exploring Long-Term Protective Effect Of High Vertical Sand Barrier On Top Of Complex Longitudinal Sand Ridge In Taklamakan Desert, Jin Changning

Journal of China & Foreign Highway

By taking the high vertical sand barriers deployed on the top of the complex longitudinal sand ridges in the hinterland of Taklamakan Desert as the object, this paper investigated the sand protection effect from the long-term perspective on the basis of several years’ comparative observation. The result analysis shows that in addition to the recognized sand blocking effect, high vertical sand barriers also have a more important role of sand fixation, which means that the barriers can change the original overall movement of sand dunes into only the falling sand slope forward, with the windward slopes basically fixed. Even if …


Study And Implementation Of Jacking Scheme Of Vertical Curve Beam With Two -Way Longitudinal Slope Without Adjusting Temporary Pier Top Elevation, Zhang Hongwu, Ke Hongjun, Chen Zhuoyi, Yang Wu Sep 2023

Study And Implementation Of Jacking Scheme Of Vertical Curve Beam With Two -Way Longitudinal Slope Without Adjusting Temporary Pier Top Elevation, Zhang Hongwu, Ke Hongjun, Chen Zhuoyi, Yang Wu

Journal of China & Foreign Highway

The bridge alignment design is the straight line+circular curve+straight two-way longitudinal slope vertical curve variable curvature steel bridge jacking. To deal with this problem, this paper analyzed the shortcomings of existing schemes such as real-time or multiple adjustments to the temporary pier top elevation, and proposed a jacking scheme of taking full advantage of the steel bridge’s characteristics including small flexural rigidity, strong adaptive deformation ability and high material strength, without adjusting the temporary pier top elevation. Additionally, the whole-process finite element simulation analysis was conducted on this scheme via a background project, with the calculation results revealing safety and …


Data Analysis And Early Warning Platform For Bridge Health Monitoring Based On Matlab-Java Fusion, Wang Zhiwen, Mao Yongjia, Ding Youliang Sep 2023

Data Analysis And Early Warning Platform For Bridge Health Monitoring Based On Matlab-Java Fusion, Wang Zhiwen, Mao Yongjia, Ding Youliang

Journal of China & Foreign Highway

Bridge health monitoring provides important support for daily operation and maintenance management of bridges. Meanwhile, real-time analysis, evaluation and early warning of bridge health monitoring data are the core requirements for enhancing bridge monitoring and safety protection, which can help grasp the operation status of bridge structures in real time and guard against major safety risks of bridge operation. This paper combined traditional signal processing and statistical analysis with modern machine learning and deep learning, and developed a platform for real-time analysis and warning of bridge health monitoring data based on Matlab-JAVA integration. Online cleaning, feature extraction, performance evaluation and …


Application Of Dry Sbs Modification Technology In Yanhai Highway, Zhang Han, Meng Chunlin, Zhao Mingfang, Lu Chuanzhong, Ji Guoqi Sep 2023

Application Of Dry Sbs Modification Technology In Yanhai Highway, Zhang Han, Meng Chunlin, Zhao Mingfang, Lu Chuanzhong, Ji Guoqi

Journal of China & Foreign Highway

Dry SBS-modified asphalt pavement technology is to produce SBS-modified asphalt mixtures by adding specific SBS modifiers, which aims to solve the performance degradation of SBS-modified asphalt in transportation and storage. By relying on the coastal highway repair projects, this paper compared the effects of different dry SBS mixing contents on the test results by the indoor dry SBS and matrix asphalt compatibility test and asphalt mixture performance evaluation test. Meanwhile, based on the test results, the recommended dry SBS mixing content for the coastal highway upper layer milling and resurfacing maintenance project was proposed and applied on a large scale …


Resilin Distribution And Abundance In Apis Mellifera Across Biological Age Classes And Castes, Audrey Anderson, Noah Keime, Chandler Fong, Andrew Kraemer, Carol Fassbinder-Orth Sep 2023

Resilin Distribution And Abundance In Apis Mellifera Across Biological Age Classes And Castes, Audrey Anderson, Noah Keime, Chandler Fong, Andrew Kraemer, Carol Fassbinder-Orth

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The presence of resilin, an elastomeric protein, in insect vein joints provides the flexible, passive deformations that are crucial to flapping flight. This study investigated the resilin gene expression and autofluorescence dynamics among Apis mellifera (honey bee) worker age classes and drone honey bees. Resilin gene expression was determined via ddPCR on whole honey bees and resilin autofluorescence was measured in the 1m-cu, 2m-cu, Cu-V, and Cu2-V joints on the forewing and the Cu-V joint of the hindwing. Resilin gene expression varied significantly with age, with resilin activity being highest in the pupae. Autofluorescence of the 1m-cu and the Cu-V …


Influence Of Ultrasound Machine Settings On Quantitative Measures Derived From Spatial Frequency Analysis Of Muscle Tissue, Scott K. Crawford, Stephanie A. Kliethermes, Bryan C. Heiderscheit, Greg Bashford Aug 2023

Influence Of Ultrasound Machine Settings On Quantitative Measures Derived From Spatial Frequency Analysis Of Muscle Tissue, Scott K. Crawford, Stephanie A. Kliethermes, Bryan C. Heiderscheit, Greg Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background Ultrasound is a powerful tool for diagnostic purposes and provides insight into both normal and pathologic tissue structure. Spatial frequency analysis (SFA) methods characterize musculoskeletal tissue organization from ultrasound images. Both sonographers in clinical imaging and researchers may alter a minimized range of ultrasound settings to optimize image quality, and it is important to know how these small adjustments of these settings affect SFA parameters. The purpose of this study was to investigate the effects of making small adjustments in a typical default ultrasound machine setting on extracted spatial frequency parameters (peak spatial frequency radius (PSFR), Mmax, Mmax%, and …


Investigation And Modification Of Single-Post Aluminum Sign Supports For Mash Crashworthiness, Rodrigo Quintero Aug 2023

Investigation And Modification Of Single-Post Aluminum Sign Supports For Mash Crashworthiness, Rodrigo Quintero

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Traffic signs are used to display information to drivers and are one of the most commonly encountered roadside structures. Although they are a vital traffic control device, signs can pose a significant safety risk to errant drivers due to their extensive placement and proximity to the roadway. Therefore, traffic signs and their supports must be designed with crashworthiness in mind to reduce the likelihood of injury in the event of a vehicle impact. Prior to 2009, these systems were evaluated using the crash testing criteria found in the National Cooperative Highway Research Program (NCHRP) Report No. 350 [1]. Currently, they …


Energy Dissipation Optimization For Circular Culverts, Chi Zhang Aug 2023

Energy Dissipation Optimization For Circular Culverts, Chi Zhang

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The principal goal of the current research is to develop and improve weir-based energy dissipator designs at the outlets of circular culverts. In the present case, we are interested in full-length weirs and staggered weirs. A review of related literature was completed and reported; a test facility was carefully designed and constructed to collect flow information in a basin downstream of a model broken-back circular culvert; instrumentation was installed to measure discharges, streamwise depths, and velocities. Both full-length and staggered weirs were tested over a range of discharges and tailwaters. The two types of weirs were subjected to two types …


Healthcare Built Environment And The Covid-19 Pandemic, A Mixed-Method Study, Mohammad Saleh Nikooopayan Tak Aug 2023

Healthcare Built Environment And The Covid-19 Pandemic, A Mixed-Method Study, Mohammad Saleh Nikooopayan Tak

All Theses

The outbreak of COVID-19 presented an unparalleled risk to public health, leading to urgent scientific efforts in understanding transmission mechanisms and mitigating risks, especially in healthcare settings. This mixed-methods study examines knowledge advancement regarding indoor air quality in healthcare facilities during the pandemic. A systematic literature review of 163 post-COVID studies identifies key research thrusts and 31 recommendations related to building ventilation, air filtration, surface disinfection, and monitoring. Comparison with over 200 pre-pandemic publications reveals both reliance on established infection control principles and unique contributions, such as detecting viral RNA in air and surface samples indicating potential airborne and fomite …


Development And Calibration Of The Lmrpm Mid-Breton River Sediment Diversion Gate Operations, Emily E. Fertitta Jul 2023

Development And Calibration Of The Lmrpm Mid-Breton River Sediment Diversion Gate Operations, Emily E. Fertitta

LSU Master's Theses

With the rate of coastal land loss in Louisiana, the state is looking for innovative ways to help restore and maintain its coastal wetlands. Sediment diversions are going to be constructed along the Lower Mississippi River to mitigate the issues by diverting river water, sediment and nutrients into adjacent wetlands. Since there are currently no real-world applications of sediment diversions, the Lower Mississippi River Physical Model is a beneficial modeling tool to study the impact sediment diversions and relative sea level rise have on the hydraulics and sediment transport processes in the river. The two river sediment diversions on the …


Correlation Analysis Between External Damages And Transverse Load Distribution Capacit Y Of Hollow Slab Bridges, Cao Hao, Sun Dunhua, Wang Zichen, Zhao Fuli, Sun Haipeng, Xiong Wen Jul 2023

Correlation Analysis Between External Damages And Transverse Load Distribution Capacit Y Of Hollow Slab Bridges, Cao Hao, Sun Dunhua, Wang Zichen, Zhao Fuli, Sun Haipeng, Xiong Wen

Journal of China & Foreign Highway

To correctly evaluate the service status of prefabricated hollow slab girder bridge, based on the measured data of apparent disease and load test of hollow slab girder bridge in reconstruction and expansion project, this paper first analyzed the data characteristics of the beam body, hinge joints, and support disease samples and obtained their statistical distribution rules. Then, according to the typical diseases (transverse cracks and hinge cracks at the bottom of the beam), the BP neural network was used to build a correlation model for them, and the close correlation between the two typical diseases of hollow slab girder bridge …


Research Of Disease Analysis And Reinforcement Technology For Typical Orthotropic Bridge Deck, Guo Fukuan, Zhou Shangmeng Jul 2023

Research Of Disease Analysis And Reinforcement Technology For Typical Orthotropic Bridge Deck, Guo Fukuan, Zhou Shangmeng

Journal of China & Foreign Highway

In order to effectively solve the disease problem of orthotropic steel bridge decks, this paper relied on a steel box girder cable-stayed bridge deck reinforcement project to carry out steel bridge deck disease analysis and reinforcement technology research. The results show that the main disease of steel bridge decks is fatigue cracking. The fatigue cracks are numerous, short, and deep, and they continuously grow and cause more severe disease. The excessive fatigue stress amplitude is the main factor leading to the fatigue cracking of steel bridge decks. Once the crack occurs, the stress amplitude of the crack tip increases continuously, …


Review Of Research Progress Of Frame Beam Anchore D Structure In Slope Supporting, Zhang Junhui, Zhou Qinwei, Li Feng, Zhang Shiping Jul 2023

Review Of Research Progress Of Frame Beam Anchore D Structure In Slope Supporting, Zhang Junhui, Zhou Qinwei, Li Feng, Zhang Shiping

Journal of China & Foreign Highway

This paper summarized the research status of frame beam anchored structures in slope supporting and reinforcement engineering in China and abroad. It analyzed the results of structural design, model test, and field construction. Through induction and analysis, it is found that the current design of frame beam anchored structure has certain limitations, and it is necessary to form a universal design theory and method. The model test of frame beam anchored structure in slope supporting is limited by the test equipment and conditions and fails to be carried out on a large scale. The key points and standards of the …


Experimental Study On Interface Fatigue C Haracteristics Of Asphalt P Avement Pothole Patch Under External Factors, Ai Changfa, Shao Zhutao, Huang Yangquan, Ren Dongya Jul 2023

Experimental Study On Interface Fatigue C Haracteristics Of Asphalt P Avement Pothole Patch Under External Factors, Ai Changfa, Shao Zhutao, Huang Yangquan, Ren Dongya

Journal of China & Foreign Highway

After the asphalt pavement patch for potholes is put into use, the interface joints around it are prone to fatigue and durability problems under the action of external factors such as the natural environment and driving load effect. In order to analyze the fatigue characteristics of the repaired interface joints under the action of external factors, the four-point bending fatigue test and pull-out test, combined with the results of orthogonal analysis, were used to determine the best bonding scheme of the repaired interface. The influence of external factors such as temperature, frequency, and strain level on the fatigue life of …


Case Study Of Steel Wire Corrosion In Hoist Cable Of Half ⁃Through Arch Bridge, Xu Hongsheng, Jiang Lei, Yan Donghuang Jul 2023

Case Study Of Steel Wire Corrosion In Hoist Cable Of Half ⁃Through Arch Bridge, Xu Hongsheng, Jiang Lei, Yan Donghuang

Journal of China & Foreign Highway

In order to understand the causes and development rules of steel wire corrosion diseases inside the hoist cable of half⁃through and through arch bridges, this paper systematically studied the defects and loopholes of the protection system for the hoist cable of two half⁃through steel arch bridges by disintegrating the old hoist cables of Yuehai Bridge in Yinchuan and Xiangjiang Bridge in Heishipu Street in Changsha City. It probed into the distribution rules of corrosion diseases of steel wire inside the hoist cables. The main reasons leading to the difference in steel wire corrosion disease inside the old hoist cables of …


Influence Of Proximity Construction Of A New Pile Foundation On Adjacent Metro Tunnel, Jin Shengji, Mu Anxin, Bi Bo, Xu Chao, Yu He Jul 2023

Influence Of Proximity Construction Of A New Pile Foundation On Adjacent Metro Tunnel, Jin Shengji, Mu Anxin, Bi Bo, Xu Chao, Yu He

Journal of China & Foreign Highway

The construction of a bridge pile foundation and cap not only causes disturbance to its foundation and surrounding soil but also has a certain influence on adjacent existing structures. In order to study the influence of new pile foundation proximity construction on tunnels adjacent to subway sections, this paper took the pile foundation construction process of auxiliary bridge extension on both sides of Shenyang Changqing Bridge as the research object and adopted Midas/GTS finite element numerical simulation and construction monitoring methods to study the influence of new pile foundation proximity construction on tunnels adjacent to subway sections. The results show …


Research On Cyclic Accumulative Strain Characteristics Of Structured Soft Clay, Ding Zhi, Yu Jiangang, Sun Miaomiao, Wang Jiawei, Ye Ke Jul 2023

Research On Cyclic Accumulative Strain Characteristics Of Structured Soft Clay, Ding Zhi, Yu Jiangang, Sun Miaomiao, Wang Jiawei, Ye Ke

Journal of China & Foreign Highway

Due to its structural properties, natural soft clay is prone to produce large cumulative deformation under cyclic loads such as traffic, which has a great impact on engineering. In order to solve the deformation problem caused by structural failure of soft clay under dynamic action, dynamic characteristics of undisturbed soft clay near a highway in Hangzhou were tested by the dynamic triaxial device under cyclic loading, and the dynamic characteristics of saturated undisturbed soft clay under different effective consolidation confining pressures, vibration frequencies, and dynamic stress ratios under K0 (static earth pressure coefficient) consolidation conditions were studied. The results show …


Experimental Study On Time ⁃Varying Characteristics Of Saturated Water Content Of Granite Residual Soil In Acid⁃Etched Environment, Zhang Maolin, Xie Qingzhong, Fu Helin, Zhang Meng, Li Qinglong, Dong Hui Jul 2023

Experimental Study On Time ⁃Varying Characteristics Of Saturated Water Content Of Granite Residual Soil In Acid⁃Etched Environment, Zhang Maolin, Xie Qingzhong, Fu Helin, Zhang Meng, Li Qinglong, Dong Hui

Journal of China & Foreign Highway

In order to clarify the correlation between saturated water content variability and slope stability, characteristic tests on saturated water content of granite residual soil affected by acid were carried out. Direct shear tests were carried out to test the variation rule of saturated water content and its characteristic value under the influence of vertical loading and acidification time, and the internal causes of variation were deduced based on the structural characteristics obtained by microscope electron microscopy. The results show that: ① The vertical pressure σ = 300 kPa is the turning point of the linear and nonlinear relationship, and under …


Effect Of Activator On Compressive Strength Of Steel Slag Powder Cement Soil, Chen Fei, Wang Yanchun, Du Sujun Jul 2023

Effect Of Activator On Compressive Strength Of Steel Slag Powder Cement Soil, Chen Fei, Wang Yanchun, Du Sujun

Journal of China & Foreign Highway

In order to reasonably solve the environmental pollution caused by steel slag, steel slag powder was used to improve cement soil. The optimal mix ratio was determined by a laboratory unconfined compressive strength test to prepare steel slag powder cement soil. In view of of low activity and limited compressive strength enhancement effect of steel slag powder, three kinds of activators including sodium hydroxide, silica fume, and calcium chloride were selected to be added to steel slag powder cement soil, so as to study the strength variation rule. The results show that the strength of cement soil can be improved …


Influence Of Steel Fiber And Polymer Emulsion On Mechanical Properties And Microstructure Of Concrete, Guo Guanglei, Sun Shiqiang, Li Ying, Zheng Yiwei, Mei Yingjun Jul 2023

Influence Of Steel Fiber And Polymer Emulsion On Mechanical Properties And Microstructure Of Concrete, Guo Guanglei, Sun Shiqiang, Li Ying, Zheng Yiwei, Mei Yingjun

Journal of China & Foreign Highway

The microstructure and mechanical properties of concrete were improved by adding steel fiber and polymer emulsion. The working properties and mechanical properties of steel fiber concrete, polymer emulsion-modified concrete, and steel fiber polymer concrete were tested at 3 d, 28 d, and 90 d. Nitrogen adsorption test, mercury injection test, and density method were used to obtain the total pore volume, median pore size, and closed porosity of concrete. The influence of steel fiber and polymer emulsion on the microstructure and mechanical properties of concrete was analyzed. The results show that the compressive strength of concrete after adding steel fiber …


Research On Budget Quota Of Highway Bridge Crack Treatment, Chang Ding, Yu Licun Jul 2023

Research On Budget Quota Of Highway Bridge Crack Treatment, Chang Ding, Yu Licun

Journal of China & Foreign Highway

In view of the lack of a unified budget quota for concrete structure crack treatment, a large number of measured data and fuzzy analytic hierarchy process were used to calculate the consumption of budget quota through the amplitude difference coefficient of construction quota. According to the technical specifications of highway bridge reinforcement engineering, reasonable crack treatment methods and engineering contents were determined, and the quota of structure crack treatment was prepared by using the physical quantity. The quota cost was compared with actual engineering cases. The results show that the quota cost and the actual project cost are basically at …


Effect Of Nano ⁃Metakaolin On Frost Resistance Of Concrete, Li Zhenfa Jul 2023

Effect Of Nano ⁃Metakaolin On Frost Resistance Of Concrete, Li Zhenfa

Journal of China & Foreign Highway

The denudation per unit area, relative dynamic elastic modulus, mechanical strength, and fracture characteristics of concrete with different nano-metakaolin contents before and after freezing and thawing were studied. The results show that nano-metakaolin can significantly improve the freezing resistance of concrete, and the denudation per unit area and relative dynamic elastic modulus loss rate of modified concrete are significantly improved compared with the reference group. The mechanical strength and fracture properties of nano-mekaolin-modified concrete before and after freezing and thawing are higher than those of the control group, and the mechanical strength, fracture toughness, and fracture energy loss rate are …


Research Progress On Properties Of Fiber Modified Asphalt Mixture, Liang Bo, Zhang Haitao, Liu Zheng, Liao Wei Jul 2023

Research Progress On Properties Of Fiber Modified Asphalt Mixture, Liang Bo, Zhang Haitao, Liu Zheng, Liao Wei

Journal of China & Foreign Highway

As a kind of asphalt mixture additive and stabilizer, fiber can effectively improve the performance index of asphalt pavement and extend the service life of asphalt pavement. Based on the analysis of relevant literature in China and abroad, this paper summarized the action mechanism of fiber modified asphalt and asphalt mixture, the effect of fiber content on properties, and the characteristics of different types of fiber modified asphalt. Fiber can effectively improve the high temperature property, low temperature property, and fatigue property of asphalt mixture, especially the resistance to low temperature and fatigue cracking of asphalt mixture. The modification effect …