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Articles 181 - 210 of 845

Full-Text Articles in Civil and Environmental Engineering

Installation Direction Design And Construction Control Of Sliding Bearing Of Continuous Girder Bridge, Guan Changlu, Sun Xiudong, Dong Hao, Wang Xingzhou Feb 2025

Installation Direction Design And Construction Control Of Sliding Bearing Of Continuous Girder Bridge, Guan Changlu, Sun Xiudong, Dong Hao, Wang Xingzhou

Journal of China & Foreign Highway

Continuous girder bridges can improve the structural stress,increase the structural bearing capacity,and promote ride comfort.However,some continuous girder bridges suffer from issues such as bearing dislocation,upper torsion,and damage to seismic arrestors.To identify deficiencies in current design and construction control,an in-depth analysis of these issues was conducted.The findings reveal the main reason is that the bidirectional sliding bearings (nearly half of the total ) fail to provide horizontal force,and the main sliding direction of the unidirectional sliding bearings is inconsistent with the deformation of the bridge superstructure.In this paper,factors including temperature-induced deformation,material shrinkage,elastic compression,creep,and construction process control of the bridge superstructure were …


Crack Propagation Of Vehicle‑Steel Bridge Deck Slabs Based On Pavement Damage, Tang Sheng, Yin Xinfeng, Zhang Ming, Yan Wanli Feb 2025

Crack Propagation Of Vehicle‑Steel Bridge Deck Slabs Based On Pavement Damage, Tang Sheng, Yin Xinfeng, Zhang Ming, Yan Wanli

Journal of China & Foreign Highway

In order to study the influence of vehicles under different pavement damage conditions on crack propagation of welded toe at the roof of steel bridge deck slabs,finite element models of suspension bridges,fine vehicles,and local steel bridge deck slabs were established,and multiple groups of obstacle heights were set to simulate pavement damage.The explicit dynamic analysis program was used to simulate vehicle-bridge coupling vibration and extract the forces of vehicles on the steel bridge deck slabs at different lanes,speeds,and obstacle heights.The crack propagation life of the welded toe at the roof was obtained by applying them to a local steel bridge deck …


Calculation Of Socket Depth For Circular Pipe Pier-Bearing Platform Socket Connection, Chen Jingli, Xiao Feng, Wang Zhigang, Wang Zhihai, Xu Yan Feb 2025

Calculation Of Socket Depth For Circular Pipe Pier-Bearing Platform Socket Connection, Chen Jingli, Xiao Feng, Wang Zhigang, Wang Zhihai, Xu Yan

Journal of China & Foreign Highway

The minimum socket depth for circular pipe pier-bearing platform socket connection can be calculated according to Article C.0.3 in the Specifications for Design of Highway Precast Concrete Bridges (JTG/T 3365 -05—2022 ).In order to enable engineering designers to fully understand and correctly apply the calculation formula in this article,this paper first introduced the main technical features of the typical connection scheme,as well as the structural failure principles and objectives formulated in the specification of the typical connection scheme.Then,it briefly introduced the experimental research content and results of the typical connection scheme and explained the key construction measures and their functions …


Reliability Analysis Of Long‑Span Concrete Box Arch Bridge Under Temperature Effect Combinations, Zheng Junlin, Jiang Youbao, Zheng Xinhao, Lu Naiwei Feb 2025

Reliability Analysis Of Long‑Span Concrete Box Arch Bridge Under Temperature Effect Combinations, Zheng Junlin, Jiang Youbao, Zheng Xinhao, Lu Naiwei

Journal of China & Foreign Highway

The existing design methods for concrete arch bridge structures do not consider the random characteristics of the eccentricity generated by load effects and overlook the influence of stochastic eccentricity on structural reliability.To address this deficiency,a calculation model for eccentricity under temperature effect combinations was derived.The random characteristics of eccentricity for different sections of the main arch of concrete arch bridges and their sectional bearing capacities were analyzed under different load parameter combinations.By utilizing the Monte Carlo method,reliability indices were computed for different sections of the main arch and different load parameter combinations after considering the random characteristics of eccentricity.The results …


Preparation And Performance Of Emulsified Asphalt With High-Temperature Resistant And Wheel Sticking-Free Effects, Yan Han, Zha Xudong, Kang Xiaogang, Gong Yan, Zhang Zhengji, Zhang Wenshuai Feb 2025

Preparation And Performance Of Emulsified Asphalt With High-Temperature Resistant And Wheel Sticking-Free Effects, Yan Han, Zha Xudong, Kang Xiaogang, Gong Yan, Zhang Zhengji, Zhang Wenshuai

Journal of China & Foreign Highway

To address the problem of wheel sticking at high temperatures in the construction process of existing wheel sticking-free emulsified asphalt of tack coat,this paper adopted the composite modification method of 70# and 15# matrix asphalt and waterborne polyurethane resin (WPR ) to prepare hard asphalt-WPR (HA-WPR )-modified emulsified asphalt in accordance with the high-temperature resistant and wheel sticking-free requirements.Through a series of laboratory tests,the technical performance,wheel sticking-free performance,and interlayer bonding performance of the emulsified asphalt were researched and compared with ordinary wheel sticking-free emulsified asphalt and ordinary emulsified asphalt tack coat oil.The results show that the technical performance of the …


Model Analysis Of Axial Compressive Mechanical Properties Of Concrete Column Constrained By Textile-Reinforced Engineered Cementitious Composites, Ma Gao, Wang Zhaoyang Feb 2025

Model Analysis Of Axial Compressive Mechanical Properties Of Concrete Column Constrained By Textile-Reinforced Engineered Cementitious Composites, Ma Gao, Wang Zhaoyang

Journal of China & Foreign Highway

In order to avoid the problem of matrix cracking in textile-reinforced concrete (TRC ),a reinforcement method of textile-reinforced engineered cementitious composites (ECC ),namely TRECC composed of textile and high-performance ECC was proposed.However,the research on the axial compressive mechanical properties of TRECC-constrained concrete in China and abroad is still insufficient,and there is a lack of reliable strength and ultimate strain analysis models.A total of 116 axial compression test results of TRC-constrained concrete columns and 125 axial compression test results of TRECC-constrained concrete columns were collected.The confinement mechanisms and failure modes of TRECC and TRC-constrained concrete were compared.Then,the strength models and ultimate …


Key Techniques For Constructing Flexible Geosynthetic Reinforced Soil Abutments, Yu Xiaoxiao, Xu Chao, Li Haoyu, Zuo Binli Feb 2025

Key Techniques For Constructing Flexible Geosynthetic Reinforced Soil Abutments, Yu Xiaoxiao, Xu Chao, Li Haoyu, Zuo Binli

Journal of China & Foreign Highway

The flexible geosynthetic reinforced soil (GRS ) abutments offer several advantages,including cost saving,reduced bridgehead misalignment,and good seismic performance,showing great potential for application in transportation engineering both in China and abroad.The flexible GRS abutment is essentially composed of a composite structure formed by closely spaced layers of geosynthetic reinforcement material,and the construction quality and load-bearing capacity are crucial to the success of the project.To ensure construction quality and study the construction process of flexible GRS abutments,a construction site monitoring method was adopted.Based on the experience from the construction of a vehicular overpass on the Wuwei ‒ Yuexi Expressway,the quality control measures …


Research On Mechanical Entry Excavation And Reinforcement Measures For Large Cross-Section Tunnel, Liang Xiao, Li Ke, Guo Hongyan, Hu Xuebing, Yao Chengrui Feb 2025

Research On Mechanical Entry Excavation And Reinforcement Measures For Large Cross-Section Tunnel, Liang Xiao, Li Ke, Guo Hongyan, Hu Xuebing, Yao Chengrui

Journal of China & Foreign Highway

With the innovation of tunnel construction techniques and mechanical equipment,mechanical drilling and blasting for mountain tunnels have gradually developed.However,several challenges exist during the mechanical entry excavation for mountain tunnels,including the significant influence of geological factors,limited equipment adaptability,and constrained working space.This research,based on a specific tunnel project,utilized FLAC3D finite difference software to study the mechanical excavation method and auxiliary reinforcement measures for shallow-buried segments at the large cross-section tunnel portal.A comparative analysis was conducted on the displacement of surrounding rock,the stress of supporting structures,and the variation of plastic zones before and after tunnel face reinforcement for different advances per cycle and …


Application Research Of Bim Technology In Highway Prefabricated Bridge Scheme Design, Li Jinlong, Wang Xinnan, Liu Dongsheng, Chen Zhongzhi Feb 2025

Application Research Of Bim Technology In Highway Prefabricated Bridge Scheme Design, Li Jinlong, Wang Xinnan, Liu Dongsheng, Chen Zhongzhi

Journal of China & Foreign Highway

At present,the highway bridge scheme requires continuous adjustments and upgrading due to iterative updates of design data and refined investigation of the surrounding environment of the bridge site.This paper upgraded the traditional route design software,developed a GIS-integrated platform,built a three-dimensional environment with design data as the core,and created a bridge scheme model through parametric intelligent design.It also evaluated and optimized the bridge scheme based on the integration of the bridge model and the surrounding environment.The results show that by using BIM technology,the forward design of a bridge scheme based on a three-dimensional environment is realized.This approach automates the scale statistics …


Simulation-Based Models For Postearthquake Response: A Survey And Research Directions, Abhijit Gosavi, Lauryn A. Spearing, Lesley H. Sneed Feb 2025

Simulation-Based Models For Postearthquake Response: A Survey And Research Directions, Abhijit Gosavi, Lauryn A. Spearing, Lesley H. Sneed

Engineering Management and Systems Engineering Faculty Research & Creative Works

Computer simulation is increasingly being used by emergency planners as a tool to improve disaster response given that it can model real-world scenarios, such as earthquakes. Although there has been an increase in simulation research focused on disaster response, much of this literature is from disparate fields and across disaster scenarios. To bridge this gap, this paper surveys simulation-based models for post-earthquake response from the year 2000 onward. Advantages of simulation over closed-form statistical models are discussed. Three main subproblems in post-earthquake response models are explored: (1) service distribution (e.g., food, water), (2) infrastructure restoration (at the building and transportation …


Rheology And Early-Age Structure Development In Binary And Ternary Blends Modified With Novel Graphene Types, Sahil Surehali, Collin Gustafson, Sayee Srikarah Volaity, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath Feb 2025

Rheology And Early-Age Structure Development In Binary And Ternary Blends Modified With Novel Graphene Types, Sahil Surehali, Collin Gustafson, Sayee Srikarah Volaity, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Interest in the use of graphene to enhance the properties of cementitious materials is growing, but major impediments in implementation are the cost of graphene and changes in binder rheology attributable to these nanomaterials. This study explores the influence of novel, cost-effective, environment-friendly, and mass-producible graphene on the rheology and early-age structure development of cementitious binders. Two novel graphene types—fractal graphene (FG) and reactive graphene (RG)—are used in plain cement mixtures as well as those containing 30 % (by mass) of fly ash and/or limestone powder, at low dosages of ≤0.02 % by mass of binder. The early- and later-age …


Thermally Stimulated Stiffening And Fly Ash's Alkaline Activation By Ca(Oh)2 Addition Facilitates 3d-Printing, Xiaodi Dai, Sharu Bhagavathi Kandy, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant Feb 2025

Thermally Stimulated Stiffening And Fly Ash's Alkaline Activation By Ca(Oh)2 Addition Facilitates 3d-Printing, Xiaodi Dai, Sharu Bhagavathi Kandy, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

3D-printing could offer substantial benefits to the construction industry including the fabrication of customized/bespoke components, eliminating formwork, and reducing material waste. Despite these advantages, control of the pumpability, extrudability, and buildability of 3D-printed concrete (3DPC) remains challenging. This study demonstrates how the use of fly ash (FA) enables enhanced thermal stiffening, and rapid alkali-activation in the presence of portlandite (Ca(OH)2, CH). In general, blends of CH and FA exhibit less structural build-up at low temperatures, but upon reaching a trigger temperature of 75 °C, these blends achieve rapid stiffening, at rates of ∼800 Pa/s. The rapid stiffening arises from the …


Effects Of Gypsum And Limestone On Early-Age Hydration And Strength Optimization In Belite Calcium Sulfoaluminate Cement, Sai Akshay Ponduru, Bryan K. Aylas-Paredes, Taihao Han, Advaith Neithalath, Narayanan Neithalath, Gaurav Sant, Aditya Kumar Feb 2025

Effects Of Gypsum And Limestone On Early-Age Hydration And Strength Optimization In Belite Calcium Sulfoaluminate Cement, Sai Akshay Ponduru, Bryan K. Aylas-Paredes, Taihao Han, Advaith Neithalath, Narayanan Neithalath, Gaurav Sant, Aditya Kumar

Materials Science and Engineering Faculty Research & Creative Works

Belite calcium sulfoaluminate cement (CSAB), an alternative to Portland cement, exhibits excellent strength at both early and later ages. However, due to its high belite content, the carbon reduction from this type of cement is not sufficient when compared to other alternative cements. To further enhance CSAB's sustainability, this study investigates the performance of CSAB when partially replaced by low-carbon mineral additives (i.e., limestone and gypsum). The primary objective is to identify the optimal mixture design by incorporating gypsum and limestone to formulate a sustainable binder that maintains high compressive strength. The CSAB is replaced (with both additives) by up …


Integrating Off-Spec Scms Into Plc Blends, George A. Qubty Jan 2025

Integrating Off-Spec Scms Into Plc Blends, George A. Qubty

Civil Engineering Theses - Archive

Off-spec supplementary cementitious materials (SCMs) remain underutilized due to variability in reactivity and non-conformance with existing standards. This study evaluates the hydration behavior and fresh-state and mechanical performance of these materials in Portland limestone cement (PLC) systems. One Class F fly ash (FA), one bottom ash (BA), and two calcined clays (HACC and LACC) were evaluated as 20 % replacements to PLC. Hydration behavior was characterized using isothermal calorimetry and thermogravimetric analysis (TGA), while fresh-state and mechanical performance were assessed through flow table, Vicat setting time, load–crack mouth opening displacement (CMOD) flexural testing, and compressive strength testing. HACC increased compressive …


Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field Jan 2025

Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field

Materials Science and Engineering Faculty Research & Creative Works

Nitrogen pickup during air induction melting can result in porosity and a loss of fracture toughness in ultrahigh-strength quenched and tempered steel castings. Nitrogen atoms are easily adsorbed into liquid steel upon exposure to the air, and argon shrouding alone has limited effectiveness. Previous studies have shown that proper charge sequencing and maintaining a high amount of dissolved oxygen in the melt prior to tapping and deoxidation can limit nitrogen pickup in the melt. In the current study, the effect of melt practice and charging procedure on nitrogen pickup was studied as a function of hold time in a series …


Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali Jan 2025

Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali

Materials Science and Engineering Faculty Research & Creative Works

Efficient oxide scale removal is critical for maintaining surface quality and process efficiency in steel manufacturing. This study optimizes water jet descaling by evaluating the performance of flat and rotary jet nozzles under varying process parameters. Using a combined approach of experimental analysis and computational fluid dynamics, it investigates the influence of pressure (138–275 bar), lead angle (0°, 15°, 25°), working distance (50–100 mm), and spray angle (15°–25°) on descaling efficiency. Findings indicate that flat jet nozzles achieve superior performance at short working distances due to concentrated impact forces, while rotary jet nozzles sustain efficiency over extended distances through dynamic …


Ultrafast Belite (Β-C2s) Production Using Biofuel-Based Combustion Synthesis, Shubham Agrawal, Sayee Srikarah Volaity, Oluwadamilare Charles Adesina, Bryan K. Aylas-Paredes, Taihao Han, Srinivas Kilambi, Aditya Kumar, Narayanan Neithalath Jan 2025

Ultrafast Belite (Β-C2s) Production Using Biofuel-Based Combustion Synthesis, Shubham Agrawal, Sayee Srikarah Volaity, Oluwadamilare Charles Adesina, Bryan K. Aylas-Paredes, Taihao Han, Srinivas Kilambi, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

This study presents a novel low-temperature, combustion synthesis (CS) approach for the rapid production of belite-rich cements. CS leverages the exothermic heat released from the combustion of biofuels such as lignin and/or biomass, intermixed with pelletized limestone and quartz. At an imposed furnace temperature of ∼700°C (as opposed to 1200°C–1300°C required in a conventional kiln), the source materials are rapidly transformed to belite, resulting in energy, emissions, and economic benefits. This work explores the influence of various process parameters, viz., fuel types and contents, airflow rate, porosity, holding temperature, and holding time on the efficiency of CS-based belite synthesis. Through …


Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck Jan 2025

Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck

Materials Science and Engineering Faculty Research & Creative Works

The effect of gating system design on the inclusion population and size distribution in an aluminum-killed low-alloy advanced high strength steel casting was studied. A mold with four different gating systems: pressurized and non-pressurized with side risers, naturally pressurized with a side riser, and naturally pressurized with a top riser, was designed using computational fluid dynamics and solidification software. The design allowed inclusion populations in castings produced with each gating system to be compared during the same pouring event. Samples taken from different positions just below the top surface of each casting were analyzed using an SEM/EDS system with automated …


Investigating The Effects Of Fly Ash On The Properties Of Silica-Deficient High Alumina Materials, Sai Akshay Ponduru Jan 2025

Investigating The Effects Of Fly Ash On The Properties Of Silica-Deficient High Alumina Materials, Sai Akshay Ponduru

Doctoral Dissertations

This research is made up of five studies mainly focused on attaining sustainability in high alumina cements like calcium aluminate cement (CAC) and calcium sulfoaluminate belite cements (CSAB) by partially replacing them with additives and supplementary cementitious materials (SCMs) like fly ash (FA). The first study focused on understanding the reaction kinetics of CAC and FA binders at different replacement levels (i.e. between 10%-to-50% by mass) and their effect on mechanical properties. It was also shown that the reactive nature of FAs can be determined by calculating a single parameter called number of constraints (nc) derived from topological constraint theory. …


Reuse Of Calcium Carbonate (Caco3) Recovered From Discarded Carpets As Filler In Fiber-Reinforced Polymer (Frp) Composites, Roshan Devkota Jan 2025

Reuse Of Calcium Carbonate (Caco3) Recovered From Discarded Carpets As Filler In Fiber-Reinforced Polymer (Frp) Composites, Roshan Devkota

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over four billion pounds of carpet are discarded annually in the United States, making carpet waste a significant environmental concern. Calcium carbonate (CaCo₃) constitutes up to 45% of the mass of most synthetic carpets. Reusing this CaCo₃ as a filler in the rapidly growing fiber-reinforced polymer (FRP) industry, which is projected to reach USD 10.38 billion, presents a low-cost, practical approach to developing a market-based solution to post-consumer carpet waste.

This study investigates the reuse of CaCo₃ recovered from discarded carpet backing as a filler in FRP composites, focusing on its mechanical viability in comparison to virgin CaCo₃. The methodology …


A Comparative Study Between Soft Structures And Hard Structures For The Protection Of Egypt’S Coastlines Against Climate Change, Donia Eldwib Dec 2024

A Comparative Study Between Soft Structures And Hard Structures For The Protection Of Egypt’S Coastlines Against Climate Change, Donia Eldwib

Theses and Dissertations

Coastal communities worldwide face unprecedented threats from climate change, with rising sea levels, increased storm intensities, and accelerated coastal erosion posing significant risks. Egypt, with over 3,000 kilometers of coastlines along the Mediterranean and Red Seas, it is particularly vulnerable due to its densely populated and economically critical low-elevated coastal zones. With the Mediterranean Sea, and the Nile Delta specifically under huge threats, this study examines the different coastal protection strategies used to address these climate change impacts. Different coastal protection structures have been used throughout the years starting with the well-known hard structures moving on to greener alternatives such …


Optimization Of Construction Scheme Of Ultra‑Large Special‑Shaped Foundation Pit Adjacent To Existing Station And Temporary Steel Bridge, Chen Dengwei Dec 2024

Optimization Of Construction Scheme Of Ultra‑Large Special‑Shaped Foundation Pit Adjacent To Existing Station And Temporary Steel Bridge, Chen Dengwei

Journal of China & Foreign Highway

With the intensifying development density of urban underground space in China,the impact of ultra-large foundation pit construction on the normal operation of adjacent structures cannot be ignored.Relying on the Huangmugang Comprehensive Transportation Hub Project in Shenzhen,this paper studied the deformation of the envelope structure and soil caused by the excavation of the ultra-large special-shaped foundation pit,as well as the structural response of the deformation of the adjacent existing station and the temporary steel bridge.The paper optimized the construction scheme of the special-shaped foundation pit excavation.The results show that the deformation trend of the envelope structure on the north and south …


Friction‑ 1d Transformer : A 1d Vision Transformer Hybrid Model For Skid Resistance Prediction On Asphalt Pavements, Pei Feifei, Nie Zilong, Xu G Uomin, Zhan You, Gong Xianqi, Ai Changfa, Deng Yuan, Ji Zhengyun, Wang Shifa Dec 2024

Friction‑ 1d Transformer : A 1d Vision Transformer Hybrid Model For Skid Resistance Prediction On Asphalt Pavements, Pei Feifei, Nie Zilong, Xu G Uomin, Zhan You, Gong Xianqi, Ai Changfa, Deng Yuan, Ji Zhengyun, Wang Shifa

Journal of China & Foreign Highway

The friction performance of road surfaces is an important indicator of highway safety,which is closely related to road texture.In this paper,a set of three-dimensional denoising methods for road texture data with different noise levels was proposed,which could effectively remove noise while preserving local texture features.In addition,a skid resistance prediction model named Friction- 1D Transformer was developed based on the design concept of Vision Transformer (VIT) for skid resistance evaluation of asphalt pavements.Unlike traditional convolutional neural networks,the Friction- 1D Transformer utilized positional encoding structures and multi-head attention mechanisms to extract global features from one-dimensional (1D) texture signals along the direction of …


Experimental Investigation On Shrinkage Effect Of Ultra‑High Performance Concrete Under Steam Curing, Li Bing, Yang Tengyu, Fang Changle, Luo Zirun, Li Chuanxi, Tan Ke Dec 2024

Experimental Investigation On Shrinkage Effect Of Ultra‑High Performance Concrete Under Steam Curing, Li Bing, Yang Tengyu, Fang Changle, Luo Zirun, Li Chuanxi, Tan Ke

Journal of China & Foreign Highway

Determining the free shrinkage of U HPC is an important basis for analyzing the shrinkage effect of steel UHPC composite bridge deck.Therefore,based on the UHPC materials to be used in a project,three batches of UHPC free shrinkage specimens were made,and three specimens were made in each batch.By testing the strain and temperature of specimens during curing,the free shrinkage strain-age curve and temperature-age curve of UHPC were obtained.The development and variation law of UHPC shrinkage strain are discussed.Based on the experimental results,the equivalent time is introduced on the basis of Arrhenius empirical formula,and a modified model of free shrinkage is proposed.Finally,based …


Mechanical And Vegetative Performance Of Bamboo Fiber‑Reinforced Eco‑Concrete With Recycled Aggregate, Li Tao, Deng Bofan, He Maolin, Liu Ting, Chen Houde Dec 2024

Mechanical And Vegetative Performance Of Bamboo Fiber‑Reinforced Eco‑Concrete With Recycled Aggregate, Li Tao, Deng Bofan, He Maolin, Liu Ting, Chen Houde

Journal of China & Foreign Highway

In response to the current common urban construction waste disposal issue,this study utilized processed recycled construction waste aggregate and bamboo waste materials to produce bamboo fiber-reinforced eco-concrete with recycled aggregate.By adjusting the dosage of bamboo fiber,the effects of the dosage of bamboo fiber on the mechanical and vegetative performance of the concrete were systematically analyzed by means of orthogonal tests and verification methods.The test results indicate that bamboo fiber enhances the toughness of eco-concrete significantly.Particularly,when the dosage of bamboo fiber exceeds 3.0 kg/m3,there is a significant enhancement in the tensile performance of the eco-concrete with recycled aggregate.Due to the spatial …


Curing Law And Road Performance Of Polyurethane Mixture, Sun Shengkai, Zheng Mao, Tang Xiong, Liu Li, Zhong Shengran, Si Te Dec 2024

Curing Law And Road Performance Of Polyurethane Mixture, Sun Shengkai, Zheng Mao, Tang Xiong, Liu Li, Zhong Shengran, Si Te

Journal of China & Foreign Highway

Polyurethane mixture is composed of polyurethane binder,rubber particles,and stones.Compared with ordinary asphalt mixture,it has the characteristics of a higher content of rubber particles and large void ratios.This article first tested the viscosity-time curve and viscosity-temperature curve of one-component polyurethane and determined the compaction temperature of the polyurethane mixture.Based on the rutting test,three-point bending test,water immersion Marshall test,freeze-thaw splitting test,and pendulum friction test,the road performance of the polyurethane mixture under different replacement amounts of rubber particles was tested.The research results show that the mixing temperature of PU- 1 polyurethane mixture can be basically controlled between 73 ℃ and 81 ℃,and it …


Elimination Method Of Temperature Lag Effect In Deformation Monitoring Data Of Cable‑Stayed Bridge Structures, Liu Hongshuang, Zhai Wenqiang, Zeng Guoliang Dec 2024

Elimination Method Of Temperature Lag Effect In Deformation Monitoring Data Of Cable‑Stayed Bridge Structures, Liu Hongshuang, Zhai Wenqiang, Zeng Guoliang

Journal of China & Foreign Highway

There is a temperature lag effect in the deformation monitoring data of the bridge structure.Eliminating the temperature lag effect is of great significance in the health monitoring of the bridge structure.Based on the linear correlation between the deformation of the bridge structure and the temperature,this paper applied the goodness of fit test and proposed a time-domain translation elimination method.On this basis,by taking the long-term synchronous monitoring of the tower inclination,beam end displacement,main girder deflection,and temperature data of a cable-stayed bridge as an example,this method was used to eliminate the temperature lag effect in the deformation monitoring data and compared with …


Sensitivity Analysis Of Parameters Of Cable‑Stayed Bridges With Full Floating Spatial Frame, Liu Anqing, Yan Tengfei, Zheng Pengju, Gu Yanlin, Li Jie, Wang Qiang Dec 2024

Sensitivity Analysis Of Parameters Of Cable‑Stayed Bridges With Full Floating Spatial Frame, Liu Anqing, Yan Tengfei, Zheng Pengju, Gu Yanlin, Li Jie, Wang Qiang

Journal of China & Foreign Highway

In order to clarify the influence of design parameters on the mechanical behavior of a cable-stayed bridge of a floating system,a finite element model of the bridge was established by using the finite element analysis software MIDAS/Civil based on a single-tower double-cable plane steel-concrete composite beam cable-stayed bridge with full floating spatial frame.The sensitivity of parameters such as temperature effect,secondary dead load,and support system in the completed bridge state was analyzed and compared with the semi-floating system of the bridge.The results show that temperature and secondary dead load have a significant impact on the deflection and stress of the main …


Segment Connection Mod E For Stiffening Girder Hoisting Construction Of Long‑Span Steel Truss Girder Suspension Bridge, Shao Guangmiao, Pan Q Uan, Yan Donghuang, Xu Hongsheng Dec 2024

Segment Connection Mod E For Stiffening Girder Hoisting Construction Of Long‑Span Steel Truss Girder Suspension Bridge, Shao Guangmiao, Pan Q Uan, Yan Donghuang, Xu Hongsheng

Journal of China & Foreign Highway

In the process of stiffening girder construct ion of a long-span steel truss girder suspension bridge,different connection modes of stiffening girder segments will directly affect the internal force,alignment,and bridge state of the structure during construction.By taking the construction of the stiffening girder of a bridge as the research background,the finite element model of the whole process of the bridge was established.The advantages and disadvantages of the segmented hinge method and the segmented rigid connection method were compared,and the two-two segmented rigid connection scheme was proposed.On this basis,according to the changing law of steel truss section alignment and lower chord opening …


Linkage Control Method For Expressway Toll Stations And Plane Intersections, Lei Qing, Wang Zhaoyong, Wu Yurong, Jiang Weiwei, Luo Zhongbin Dec 2024

Linkage Control Method For Expressway Toll Stations And Plane Intersections, Lei Qing, Wang Zhaoyong, Wu Yurong, Jiang Weiwei, Luo Zhongbin

Journal of China & Foreign Highway

In order to solve the problem of vehicle queuing overflow caused by the mismatch between the expressway toll stations and the capacity of plane intersections,the formula for calculating the maximum queue length was given by analyzing the traffic operation characteristics between toll stations and plane intersections and considering vehicles ’ lane-changing behavior.Due to the strong coupling of the traffic operation between toll stations and plane intersections caused by a short distance between them,a unified linkage control optimization model was established.The research shows that if the queue length in the connecting direction of the plane intersections exceeds the allowable maximum queue …