Materials Science and Engineering Commons^™

Back‑Calculation Of Subgrade Modulus Based On Genetic Algorithm And Viscoelasticity Theory, Dai Fugui, Wang Xihui, Wu Yaguang, Li Hai

Journal of China & Foreign Highway

To improve the applicability of the PFWD detection method for the back-calculation of subgrade modulus，taking the subgrade splicing project of the west loop line in Nairobi as an example，this paper adopted 3D Kelvin viscoelasticity model and quasi-static response analysis to deduce the displacement function of viscoelastic subgrade under long-term fixed loads，and combined the principle of liner superposition of viscoelasticity with genetic algorithm to propose a new method based on multi-population genetic algorithm for the modulus back-calculation of viscoelastic subgrade.Among them，the corresponding program for back-calculation was written by Matlab.The comparison between theoretical derivation and field tests shows that the peak value …

Overall Design Concept Of Municipal Reconstruction Of Cross‑City Expressway, Fu Yuankun, Zhang Yu

Journal of China & Foreign Highway

The municipal reconstruction of the cross-city expressway is of great significance in enlarging the urban framework，refining the spatial pattern，and promoting the integrated development of clusters.However，China’s expressways seldom undergo municipal reconstruction，with less synergy formed with cities.Therefore，taking one case described above in Hebei Province as an example，this article proposed the overall design concept of integrating with the city from urban space，road networks，municipal facilities，urban ecology，cultural landscape，and other perspectives after analyzing problems in urban space，traffic，industry，landscape and urban quality in existing cross-city expressways. In addition，this paper studied and optimized the municipal reconstruction plan.Holding a theme of “municipalization ”，the plan eliminated the fragmentation of urban space …

Progress And Prospects Of Road Engineering Disease Treatment Technology In Permafrost Regions, Gao Feng, Zeng Xianzhang, Zhong Wenhua, Huang Shengyong, Zhang Junhui

Journal of China & Foreign Highway

Freeze-thaw disasters are key issues affecting the service performance and operational safety of road projects in permafrost regions.Under the combined influence of warming and humidification of the permafrost environment and engineering thermal effects，the degradation of permafrost is accelerating，exacerbating the risk of road freeze-thaw diseases.Roads in these regions are more frequently maintained and repaired to ensure service performance，with a service life lower than designed.Therefore，deepening the understanding of the disaster mechanism of road geotechnical structures and strengthening the study on engineering disease treatment technology are of great significance in promoting the construction and maintenance of high-quality and high-grade highways in frozen regions.This …

Model Test On Soil Deformation Mechanism And Damage Mode Caused By Mud Leakage From Drilled Piles In Karst Area, Jiang Mingying, Chen E ’Mei, Liu Yongcheng, Zhu Yadong, Jiang Wenkui, Xie Ruiting

Journal of China & Foreign Highway

Pile holes are often drilled through cavities in karst areas，which induces mud leakage and causes hole wall instability，ground collapse，or equipment trapping and hinders smooth construction.It is important to know the collapse mechanism of boreholes due to mud leakage，so as to optimize and determine the construction process of pile holes.In this paper，indoor model tests were used to study the deformation mechanism and damage mode of soil caused by drilling through cavities and mud leakage in pile holes under the conditions of upper clay and lower sandy soil in the karst area，so as to provide an experimental basis for the decision of …

Deformation Measurement And Safety Warning Of Highway Bridges Based On Machine Vision, Su Ziyue, Du Wenkang, Lei Dong

Journal of China & Foreign Highway

The structural safety of highway bridges plays a crucial role in traffic safety operations and regional economic development.Due to the rapid increase and complex changes in traffic loads，the demand for real-time monitoring of bridge ’s structural deformation and safety conditions has been increasingly prominent.However，the structural health monitoring system，dominated by contact sensors，has limitations such as difficult installation and construction，complicated maintenance and replacement，and the need to interrupt traffic.To this end，a non-contact deformation measurement system based on machine vision was proposed.Template matching and feature point recognition methods were utilized to achieve recognition of structural surface markings and displacement extraction of key positions.The accuracy …

Properties And Application Of Cement Improved Loess Under Low Temperature Environment In Cold Region, Li Xiangyang

Journal of China & Foreign Highway

According to the cold climate and low annual average temperature in cold regions of China，the field curing conditions of cement improvement of collapsibility loess under low temperature，room temperature，and medium temperature were simulated at 5 ℃，10 ℃，20 ℃，and 30 ℃，respectively.Based on laboratory experiments，this study analyzed the effects of curing temperature，cement content，and curing age on RCBR，unconfined compressive strength，and dynamic resilience modulus of cement improved loess.The effects of cement content and curing temperature on freeze-thaw durability and erosion resistance of cement improved loess were studied by the freeze-thaw cycle test and dynamic water erosion test.Combined with the laboratory results，the 4% and 5% cement …

Effect Of Chloride Ions On Salt Expansion Of Salinized Subgrade Fill Soil In Cold Regions, Hu Wenzhu, Wang Zhaowei, Cao Yong, Zhang Jing, Bai Ruiqiang

Journal of China & Foreign Highway

Salinized subgrade fill soil in cold regions typically comprises composite saline soil rich in sodium chloride and sodium sulfate.This study aimed to explore the mechanism of the effect of chloride ion content on salt expansion of the salinized subgrade in cold regions.Based on the calculation theory of the sodium chloride-sodium sulfate-water ternary system solution in the Pitzer ion model and combined with the FREZCHEM model，the study quantitatively analyzed the intrinsic connection between water activity，freezing factor，and supersaturation ratio with temperature and concentration ratio （η=mCl-/mSO2-4）.It investigated the variation patterns of the freezing temperature and crystallization supersaturation ratio of composite saline soil with …

Correlation Between Pavement Distress And Structural Hidden Distress, Liu Xianming, Xia Han, Hu Dongping, Yan Chen, Yang Rui, Zhong Xinran

Journal of China & Foreign Highway

The hidden distress in the pavement structure does great harm to the performance and service life of the road.In this work，based on the statistical idea of pavement distress rate in the Highway Performance Assessment Standards （JTG 5210—2018），an index of characterizing hidden distress in the pavement structure，namely pavement structure distress rate，was proposed.Based on the actual highway inspection project，the pavement distress and the hidden distress in the depth of 1 m below the pavement of a two-way four-lane highway with a length of 38 km were studied.The overall situation of pavement distress and hidden distress and their spatial distribution were analyzed statistically …

Structural Repair And Performance Evaluation Of Aged Sbs Modified Asphalt, Xu Guang, Li Qishi, Kuang Huaping, Zhang Henglong, Zhou Ruibo, Chen Yanmei

Journal of China & Foreign Highway

To rejuvenate the excellent performance of aged styrene-butadiene-styrene （SBS） modified asphalt，colza oil bio-asphalt （COA） and polymethylene polyphenyl isocyanate （PAPI） were used in this study for adjusting the asphalt components and repairing SBS molecular structure，respectively.The above-mentioned dual regeneration mechanism was verified by comparing the effects of different rejuvenation components on the physical and rheological properties，as well as the molecular weight distribution of short-term aged SBS modified asphalt.Moreover，according to the change law of rheological properties of unaged base asphalt and SBS modified asphalt under the effect of dual regeneration agent，the influence of the regeneration agent on the phase angle platform area was …

Vessel Collision Force And Anti‑Collision Performance Of Long‑Span Beam‑Arch Composite Rigid Frame Bridge, Zhang Wenming, Wang Zhiwei, Lai Yaping

Journal of China & Foreign Highway

Beam-arch composite rigid frame bridge is a new bridge type，and it has few vessel collision studies.By taking the Lijia Jialing River Bridge as the engineering background，the standard value of vessel collision force and anti-collision performance of the long-span beam-arch composite rigid frame bridge were studied.After determining the representative vessel type and vessel collision calculation conditions，the vessel-bridge collision processes of the single-pier models under various calculation scenarios were simulated by using ANSYS/LS-DYNA nonlinear finite element transient dynamic software.The simulation results of collision forces were compared with the results of several empirical formulas.Finally，the full bridge model and the ultimate bearing capacity of …

Installation And Connection Mode Of Stiffening Beam Segment Of Steel Truss Suspension Bridge, Chen Changsong, Wu Junjie

Journal of China & Foreign Highway

During the construction of long-span steel truss suspension bridges，the main girder can be connected in segment-by-segment articulated connection method and rigid-articulated connection combination method.Taking a Yangtze River Highway Bridge in Hubei Province as an example，this paper established the plane calculation model of the full bridge using the Bridge Design and Construction Monitoring System BDCMS to simulate the above two connection methods of the main girder in construction.From the comprehensive analysis of chord member internal forces and line shape of the stiffening beam，this paper finds that the rigid-articulated connection combination method is more appropriate in the construction.In addition，this paper researched the …

Seismic Responses Of Cable‑Sta Yed Bridge Considering Ponding Effect Under Near‑Fa Ult Ground Motions, Lyu Long, Yu Deen, Yuan Yuhang, Yang Huaiyu

Journal of China & Foreign Highway

To study the influence of the pon ding e ffect on seismic responses of the cable-stayed bridge under near-fault ground motions，taking a double-tower cable-stayed bridge as the engineering background，this paper analyzed the ponding response of the main bridge and the main beam of the approach bridge of the cable-stayed bridge under near-fault ground motions and the influence of the ponding response on the structural seismic response.Besides，the influence of viscous dampers and elastic cables on the ponding effect of the cable-stayed bridge under near-fault ground motions was studied，which was compared with the seismic response of the cable-stayed bridge under far-fault ground …

Multi‑Dimensional And Multi‑Point Random Seismic Response Analysis Of Long‑Span Cable‑Stayed Bridges At Different Sites, Shi Yi, Lu Lu, Fan Shuli, Shen Meng, Zuo Chunyuan, Sun Xinguo, Cao Feifei

Journal of China & Foreign Highway

To study the random seismic response of long-span cable-stayed bridges at different sites，the site transfer function was used to evaluate the influence of different site conditions on ground motion propagation.By considering the traveling wave effect and the coherence effect，the multi-point power spectrum under different site conditions was generated.By using the pseudo excitation method for solving the absolute displacement，the seismic responses of cable-stayed bridges under uniform excitation and multi-dimensional and multi-point excitation at different sites were compared.A long-span cable-stayed bridge was selected as an example，and Ansys finite element software was used to analyze the random seismic response of the bridge.By considering …

Rigid Domain Optimization Of Steel Truss Joint With Reference To Multi‑Scale Model, Liu Gaocheng, Liu Jian, Dong Chuangwen, Li Chuanxi

Journal of China & Foreign Highway

The rigidity enhancement effect of the integral gusset plate is often simulated in the calculation of an integral nodal steel truss bridge by using a beam element with a rigid arm to improve the calculation accuracy.By taking Zhongshan Lianshwan Bridge as the engineering background，an optimization method based on a multi-scale truss model for nodal rigid domain simulation was proposed and verified.Five consecutive standard sections were selected as the study objects，and the beam element model with rigid arm and the multi-scale model of gusset plate substructure were established by using Ansys.The same boundary and loading conditions were applied.The deflection of the …

Impact Resistance Of Ecc Pipe Piles Based On Ls‑Dyna, Zeng Qingyou, Ye Chenfeng, Liu Junjun, Feng Kai, Cheng Peiyuan, Chen Weihong

Journal of China & Foreign Highway

To study the impact resistance of Engineering Cementitious Composite （ECC） pipe piles，this paper used ANSYS/LS-DYNA to simulate the impact of a vertical drop hammer on the pipe piles.The HJC constitutive model of ECC was established based on key parameters obtained from static tension and compression tests and dynamic compression tests.The correctness of the finite element model was verified by split Hopkinson Pressure Bar （SHPB） tests.The parametric analysis conducted on the pipe pile models compounded with different hammer mass and impact velocity yielded dynamic responses including the displacement，time-history curve of energy，and effective plastic strain diagrams of the pipe piles under various …

Comparative Study Of Different Ventilation Methods During Tunnel Construction, Yue Kun, Bao Xiaohua, Ao Xiang, Liu Kuan, Wu Han, Li Tao, Shen Jun

Journal of China & Foreign Highway

The continuous improvement of tunnel construction technology brings a rapid increase in the speed and mileage of tunnel excavation，during which ventilation is a main problem affecting construction efficiency and safety.Taking the Zhuhai Xingye Express （West Line ） tunnel project as an example，this paper studied the influences of forced ventilation，exhaust ventilation，and hybrid ventilation on the dilution and discharge of harmful gas CO near the tunnel face and the wind speed in the tunnel.The results show that hybrid ventilation performs better in CO dilution，while exhaust ventilation has higher CO emission efficiency with a lower wind speed near the working face.Therefore，although forced ventilation …

Stability Of Excavation Face Of Double‑Mode Shield In Earth Pressure Mode Crossing Fault Zone Of Pearl River, Tong Bin, Zhang Bin, Zhu Hanbiao, Wang Shuying

Journal of China & Foreign Highway

In view of the stability of the excavation face of the double-mode shield crossing the fault zone of the Pearl River，the project of the section from Hongshengsha Station to Yufengwei Station of the second phase of Guangzhou Metro Line Seven was studied.Through numerical simulations conducted to analyze the whole area and the local high-risk area of the shield crossing the fault zone of the Pearl River，this paper explored the construction risk of the shield crossing process.Besides，this paper analyzed the influence of different support stresses and grouting pressures on the stability of the excavation face and ground deformation，and finally，the tunneling parameters …

Development Trend On Raw Materials Market Of Ready‑Mixed Concrete Under Green Construction, Ding Hu, Ding Qingjun, Lin Haojun, Zhang Zhen

Journal of China & Foreign Highway

In the face of resource depletion，high energy consumption in production，high carbon emissions，and serious pollution brought by traditional pumpcrete raw materials，a variety of new raw materials have been gradually developed and promoted to conform with the green construction promoted by China ’s civil engineering industry，witnessing a stable increase in quality，output，and social recognition.High-quality natural river sand and pebbles are in short supply at the origin，and they can be explored in old silted river channels.Gravel and manufactured sand produced using large particle size natural pebbles，limestone，construction waste，and others as raw materials will become new substitutes.In the transformation and upgrading of production enterprises which tend …

Review Of Snow And Ice Melting Techniques For Road And Bridge In Cold Regions, Tang Liyun, Shao Haitao, Tang Huaming, Qiu Peiyong, Du Xiaoqi, Zhang Lei, Peng Hui

Journal of China & Foreign Highway

Snow and ice melting of road and bridge surfaces is crucial for traffic safety，but current research on snow and ice melting techniques mainly focuses on engineering effects and technical evaluation，without the analysis and elaboration from the perspective of their mechanisms.To this end，based on the different mechanisms，this study divided snow and ice melting techniques into three types and summarized them：passive deicing，active deicing，and energy utilization deicing.This study systematically evaluated the advantages and disadvantages of traditional deicing methods such as deicing agents and mechanical deicing，analyzed two active deicing techniques，namely inhibitive freezing pavement and phase change material pavement，discussed the environmental-friendly method for road deicing …

Post‑Evaluation Method For Decision‑Making And Implementation Of Highway Maintenance Projects Based On Ahp‑Dematel, Yu Wei, Yang Na, Li Jue

Journal of China & Foreign Highway

Addressing the current lack of post-evaluation management systems related to highways，particularly highway maintenance，this paper proposed a post-evaluation method for the decision-making and implementation of highway maintenance projects based on the combination of analytic hierarchy process （AHP） and decision-making trial and evaluation laboratory （DEMATEL ）.After building a post-evaluation model for the decision-making and implementation of highway maintenance projects and designing the evaluation process，this paper calculated key factors influencing the post-evaluation of the decision-making and implementation of highway maintenance projects and their respective comprehensive weights.The research results indicate that decision-making can possess higher accuracy and efficiency under the above calculation method，providing a …

Bipolar Ionization Did Not Reduce Airborne Bacteria In A Lecture Hall, David A. Kormos, Nishit J. Shetty, Elliott T. Gall, Aaron J. Prussin, Amy Pruden, Linsey C. Marr

Mechanical and Materials Engineering Faculty Publications and Presentations

Ionization treatment of indoor air has attracted attention for its potential to inactivate airborne pathogens and reduce disease transmission, yet its real-world effectiveness remains unverified. We evaluated the impact of an in-duct, bipolar ionization system on airborne particles, including culturable bacteria, in a lecture hall. The ionizer was off with variable fan speed for 1 week, on with variable fan speed for a second week, and on with high and constant fan speed for a third week. We measured ion concentrations and aerosol particle concentrations, and we collected bioaerosol samples for analysis of 16S rRNA gene copies representing total bacteria …

An In-Situ Method For Quantifying Entropy Generation In Fatigue Via A Novel Thermographic Approach, Peyton J. Wilson

LSU Master's Theses

This work features a new approach that is used to measure the rate of plastic work during a cyclic fatigue test, based on the first and second laws of thermodynamics. Using the one-dimensional Fourier heat equation coupled with the concept of fracture fatigue entropy, the rate of plastic work during fatigue can be measured without the need to interrupt a fatigue test, and the accumulated entropy to failure can be quantified. Experimental fatigue tests are conducted on Aluminum 6061-T6 specimens under cyclic axial loading and Carbon Steel 1018 specimens under fully reversed cyclic bending loading. The obtained results in addition …

Highly Sensitive Detection Of Strontium Ions Using Metal-Organic Frameworks Functionalized Solid-State Nanochannels, Xu-Gang Wang, Zheng-Xu He, De-Fang Ding, Xue-Qin Luo, Li Dai, Wei-Qi Zhang, Qun Ma, Yu Huang, Fan Xia

Journal of Electrochemistry

Strontium-90, a highly radioactive isotope, accumulates within the food chain and skeletal structure, posing significant risks to human health. There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples. Here, solid-state nanochannels, modified with metal-organic frameworks (MOF) and specific aptamers, were engineered for highly sensitive detection of strontium ion (Sr²⁺). The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr²⁺ by aptamers amplifies the difference in ionic current signals, enhancing detection sensitivity significantly. The MOF-modified nanochannels exhibit highly sensitive detection of …

Journal Of Electrochemistry Is Selected To Entering Ici Journals Master List, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Goodbye With Tears! Deep Condolences To Academician Zhao-Wu Tian!, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

The Adviser Of Journal Of Electrochemistry Professor Christian Amatore Received The Chinese Government Friendship Award, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Overlooked Ionic Contribution Of A Chiral Dopant In Cholesteric Liquid Crystals, Hassanein Shaban, Po-Chang Wu, Yi-Fei Jia, Wei Lee

Basic Science Engineering

This study focuses on the ionic contribution by a chiral dopant added into a nematic host for preparing cholesteric liquid crystals (CLCs). Chiral structures were designated by individually incorporating two enantiomers, R5011 and S5011, into the nematic E44 to construct right- and left-handed CLCs, respectively. Characterized by the space-charge polarization, the dielectric spectra of the CLCs were investigated in the low-frequency regime, where f ≤ 1 kHz. The role of the individual chiral dopant, R5011 or S5011, at concentrations of 0–4.0 wt.% in altering the ionic properties of the CLC material was analyzed by deducing the electrical conductivity, ion density, …

Characterization Of Wood Plastic Composites Made Of Rice Straw And Recycled Low-Density Polyethylene, Waleed Mohamed Hassona Dr., Ahmed Elkassas, Nader Zaafarani

Journal of Engineering Research

In this work, the physical and mechanical properties of a fabricated wood-plastic composite (WPC) in accordance with the internationally recognized standard are investigated. The wood-plastic composite is made from recycled low-density polyethylene and mechanically processed rice straw fibers by using a specially designed extrusion machine. From the physical test, it was found that the newly developed WPC has low water absorption and thickness swelling compared to the standard limits. The mechanical tests revealed an improvement of the modulus of rupture and modulus of elasticity by the increase of fiber content to 65%. The highest recorded values of the modulus of …

Optimizing The Physical Properties Of Biochar For Co2 Adsorption Using Resonant Vibrations, Amirhosein Riahi, Richard Ladouceur

Mining Engineering

Among various Carbon Capture and Sequestration (CCS) technologies, significant emphasis has been placed on biochar as an effective post-combustion CO2 capture method. Biochar demonstrates potential as a technically effective method for stabilizing carbon. However, the efficacy of CCS based on adsorption phenomenon depends on factors such as the CO2 uptake of the adsorbent, kinetic rates, and cyclic adsorption. The study shows that Low-Frequency High Amplitude (LFHA) resonant vibratory mixing improves the physical characteristics and adsorption properties of hemp biochar. According to the results of an analysis of variance (ANOVA), increasing both the mass of biochar and the intensity of resonant …

Synergistic Approaches For Microstructural Refinement, Enhanced Mechanical And Wear Behaviour In Additively Manufactured 17-4 Ph Stainless Steel, Pradeep Kumar S

Theses and Dissertations

The surface and microstructural characteristics of additively manufactured parts play a significant role under mechanical loading. Due to its high strength, tailorable mechanical properties by heat treatment, and ease of printability, the 17-4 precipitation hardened (PH) stainless steel is gaining attention in the additive manufacturing (AM) field.

Selective Laser Melting (SLM), one of the laser-based powder bed fusion (L-PBF) processes, is capable of making fully dense metallic parts with high geometrical fidelity and greater design flexibility at high resolution. The main factors limiting the adoption of SLM are poor surface roughness, anisotropic microstructure, and the formation of micro-pores in the …