Structural Materials Commons^™

Mechanical Behavior Of Composite Structures Of Wearing Course And Underlying Layer For Asphalt Pavements, Yang Xiaohua, Yuan Zhanwen, Wen Yongbing, Zhou Chao, Wu Hao

Journal of China & Foreign Highway

The interlayer bonding state of pavement structures changes due to the influence of various factors under service conditions，and this change exhibits a significant influence on the mechanical behavior of pavement structures.Through the composite structure test and numerical analysis，the mechanical behavior of the composite structure of different wearing courses and underlying layers under different stresses and bonding states was studied.The test used three commonly used wearing course （surface layer ） materials of asphalt pavements，namely AC- 13，OGFC- 13，and SMA- 13 for comparative analysis.The test results show that different composite structures exhibit different interlayer bonding properties and fatigue characteristics due to the difference …

Shear Strength Test Of Hefei Expansive Soil Under Low Stress Conditions With Controlled Suction, Hou Chaoqun, Zhang Rongjian, Li Yongxin

Journal of China & Foreign Highway

Topsoil slide and instability of expansive soil slopes may occur under variable saturation conditions.In order to study the strength characteristics of unsaturated expansive soil under low stress conditions，several different matrix suction and stress conditions were set by unsaturated triaxial apparatus.The triaxial shear test of Hefei expansive soil was carried out，and the test data were analyzed.The test results show that when the net confining stress on the expansive soil continues to weaken，the stress-strain curve transitions from strain hardening to strain softening.The strength of unsaturated expansive soil increases with increasing matrix suction.The shear strength of shallow expansive soil shows a significant reduction …

Influence Of Aerodynamic Shape Change On Wind Resistance Performance Of Large Span Truss Bridge, Jing Dade, Su Yi

Journal of China & Foreign Highway

The development of the transportation an d tourism industry has led to bridges fulfilling additional roles，such as tourism，alongside their transportation functions，resulting in significant changes in structural aerodynamic shape and ventilation rate.This paper analyzed a double-tower single-span steel truss suspension bridge with a main span of 1 088 m，re-evaluated its wind resistance performance through the full-bridge aeroelastic model wind tunnel test，and evaluated the pedestrian comfort problem while studying the wind-resistant stability of the structure.The results indicate that the structural dynamic characteristics of the bridge remain almost unchanged before and after altering the aerodynamic shape of the bridge for its scenic spot …

Influence Of Section Selection On Mechanical Performance Of Corrugated Steel Box Culvert, Zhang Shun, Liu Baodong, Gao Meng, Wu Fei, Wang Zhihong

Journal of China & Foreign Highway

Corrugated steel box culverts exhibit a higher section utilization rate compared with circular，arched，and pipe-arch corrugated steel structures，making them more suitable for for scenarios with restricted embankment height.While numerous studies focus on strengthening strategies for corrugated steel box culverts，research on selecting cross-sectional forms is scarce.This study utilized the finite element analysis software Abaqus to develop finite element models of corrugated steel box culverts with sidewall inclination angles of 0°，5°，10°，15° and 20° respectively.The impact of these inclination angles on the structural stress and deformation outcomes was analyzed.The results indicate that increasing the sidewall inclination angles can effectively reduce vertical deformation and maximum …

Study On Anchorage Reliability For Strand Shoe And Pull Rod Of Air‑Spinning Suspension Bridge, Huang Anming, Yang Bo, Chen Long, Xie Jun, Chen Xin

Journal of China & Foreign Highway

Each strand wire of the main cable in the suspension bridge constructed by the AS method is sleeved and anchored on the strand shoes on both banks.The strand shoe transmits the strand force to the anchoring system through the pull rod.The bearing capacity of the strand shoe after the interaction between the strand shoe and the wires of the main cable，the stress state of the wires after small curvature bending，and the influence of installation accuracy of the pull rod on the anchoring reliability all need to be qualitatively and quantitatively studied and verified by the experiment.In this paper，the main cable …

Research On Gravity Anchorage Foundation Of Dadu River Bridge In Luding, Zhou Ti Ng, Tao Qiyu, Li Zejun

Journal of China & Foreign Highway

Moraine soils formed during th e Qua ternary glacial period are widely distributed in the west of China，exhibiting good mechanical properties and deep overburden.This paper studied the Dadu River bridge in Luding and investigated the influence of various foundation forms on anchorage stability in the case of considering moraine soils as the soil supporting layer of gravity anchorage foundation through theoretical analysis and numerical simulation.The findings suggest that a slant expanded foundation with a notched sill demonstrates good force-bearing capability and is cost-effective.These results can provide a reference for similar construction projects in the west of China.

Test On Water Mist Wrapped Dust Reduction Technology For Tunnels, Wang Yijun, Wang Fei, Jia Yuedi, Pan Weihua, He Xingchun, Yao Wenhui

Journal of China & Foreign Highway

In order to eliminate the dust produced by tunnel blasting more quickly and effectively，two kinds of mist spray and dust reduction schemes were put forward，which were the “air duct water mist wrapped type ” and the “vehicle-mounted water mist wrapped type ”.The field test was carried out on Jiaoding Tunnel in Yunnan.The results show that for the dust reduction technology scheme of “air duct water mist wrapped type ”，the dust concentration of the No.1 characteristic position at the tunnel face decreases to 3.87 mg/m3 after 10 minutes of dust reduction，which meets the specification requirements.For the dust reduction technology of “vehicle-mounted …

Numerical Simulation On Bearing Characteristics Of Tunnel‑Type Anchorage Of A Grand Bridge Over Qingjiang River, Yin Hongmei, Shi Qian, Zhang Yihu

Journal of China & Foreign Highway

This paper took the tunnel-type anchorage on the left bank of a grand bridge over the Qingjiang River as an example and established a three-dimensional geological generalization model based on the engineering geological analysis.In addition，the paper used different software to realize the approximate grid discrete division of complex rock mass and tunnel-type anchorage structure.FLAC3D software was used to simulate different working conditions，and the deformation characteristics and bearing capacity of the tunnel-type anchorage were obtained.It is found that the potential failure mode of the tunnel-type anchorage is that the anchor and the rock mass cut by the structural plane on the …

Study On Length Of Deceleration Lane Of Left Off‑Ramp For Urban Underground Interchanges Based On Traffic Conflicts, Wang Hailiang, Cheng Chong, Guan Hong, Ding Naikan

Journal of China & Foreign Highway

To set a reasonable range of the length of the deceleration lane in the diverge area of the left off-ramp for urban underground interchanges，the effects of the length of the deceleration lane，as well as interactions between traffic volumes and design speeds of mainline and ramp on traffic conflict in the diverge area，were exami ned.By taking the underground interchange of the Wuhan East-South Lakes Tunnel Project as an example，the VISSIM micro traffic simulation test was carried out，and the conflict rate （RCR） and exposed time to collision （TTET） were extracted.The results show that ① when the length of the deceleration lane increases，the …

Study On Safety Risk Assessment System For Waste Dump Of Mountainous Expressways, Ye Xian, Yin Hao, Zhao Xin, Wang Guanqun, Gao Yu

Journal of China & Foreign Highway

The safety of waste dump projects of mountainous expressways is related to environmental protection，water and soil conservation，highway building protection，and downstream environment-sensitive point protection，so it is necessary to put forward safety assessment methods.Based on the data analysis of 1 369 waste dumps in Yunnan Province，the safety risk factors of the waste dump engineering were proposed and summarized as five primary indicators，including site selection and design factors，construction factors，regional geological factors，external influencing factors，and data integrity factors，and 18 secondary indicators were further put forward.The group decision-making analytic hierarchy process （AHP ） model was established，and the weight of secondary indexes was determined by 64 technical …

Analysis On Design Concept Of Subgrade And Pavement Of Colombia High‑Grade Highway, Liu Tao, Hu Guanhua, Yuan Yi

Journal of China & Foreign Highway

Colombian highway design predominantly adheres to American Standards，emphasizing design concepts reflective of the United States while encompassing Colombia's engineering design habits，concepts，and characteristics.This paper introduced the main design schemes of the Colombia MAR 2 Highway Project in northern Colombia，including protection engineering，drainage engineering，subgrade filling，spoil ground，and pavement.It conducted a comparative analysis between Colombian and Chinese design concepts，highlighting similarities and disparities，and put forward the thinking of mutual learning.

Study On Flexural Behavior Of Wet Joints Of Prefabricated Steel‑Uhpc Composite Bridge Deck, Liao Wancheng, Zhao Hua, An Jiahe

Journal of China & Foreign Highway

Prefabricated steel-UHPC composite bridge deck is a new deck structure system that places the longitudinal rib at the upper layer and forms PBL shear connectors.This structure can be prefabricated in the factory and assembled on-site.The adjacent steel beams are integrated by welding，and the cast in-situ UHPC wet joints connect the adjacent UHPC bridge decks.However，these wet joints represent the structure's vulnerable segments but with little research.To this end，a full-scale model test has been conducted to study the flexural behavior of the wet joints in a steel-UHPC composite bridge deck in a practical project.The Abaqus finite element model was established and verified …

Research On Shape Optimization Of Four‑Center Circular Highway Tunnel Based On Parametric Modeling Idea, Zhu Lei, Guo Meng, Guo Jinyong, Shen Caihua, Zhang Hanyi

Journal of China & Foreign Highway

The rational cross-sectional form of the four-center circular highway tunnel contributes to enhancing the stress state of the lining structure，reducing cracks in the composite lining，and enhancing the durability of the tunnel structure.Utilizing the Ansys APDL programming platform and guided by the design principle of continuous-curvature，a parametric modeling equation for the geometrical dimensions of local tunnel shape in arch foot area was established.The calculation method and numerical simulation models for the equivalent mechanical parameters of the anchor reinforcement area were also developed.The study revealed the impact of the local tunnel shape parameter design in the arch foot area on the internal …

Thermal Insulation And Fire Protection Plaster For Frp System Incorporating Aerogel Nanoparticles And Phyllosilicates, Athnasious Ghaly

Theses and Dissertations

For more than two decades, new innovative materials have been introduced to the market such as nano materials that can be utilized for their high performance in different aspects of the construction industry. Structural repair and strengthening is one of the most demanding fields in the construction industry for innovative and high-performance materials due to its specialty. Time, quality, economy, and sustainability are the main factors that control this field, and for that, new systems keep being introduced to the market to reduce the time of repair and enhance its efficiency. Fiber Reinforced Polymers (FRP) Systems are the most advanced …

A Study On High-Frequency Bending Fatigue, Microhardness, Tensile Strength, And Microstructure Of Parts Made Using Atomic Diffusion Additive Manufacturing (Adam) And Additive Friction Stir Deposition (Afsd), Hamed Ghadimi

LSU Doctoral Dissertations

This dissertation reports the findings of several studies on the mechanical and microstructural properties of parts made using atomic diffusion additive manufacturing (ADAM) and additive friction stir deposition (AFSD). The design of a small-sized bending-fatigue test specimen for an ultrasonic fatigue testing system is reported in Chapter 1. The design was optimized based on the finite element analysis and analytical solution. The stress–life (S–N) curve is obtained for Inconel alloy 718. Chapter 2 presents the findings of ultrasonic bending-fatigue and tensile tests carried out on the ADAM test specimens. The S-N curves were created in the very high-cycle fatigue regime. …

Mechanical And Electromagnetic Properties Of Incorporating Graphene Oxide In Cementitious Mixtures, Cherif Khalil

Theses and Dissertations

This multidisciplinary study aimed at investigating the impact of incorporating graphene oxide (GO) on the mechanical properties and electromagnetic (EM) shielding effectiveness of cementitious mixtures, as well as critically examining the mechanism with which GO affects their microstructure properties. Analysis of the literature review showed that there are discrepancies in reporting the impact of GO on the mortar mix. Consequently, this study focuses on exploring the cause for such discrepancies and identifies three main factors which are thoroughly investigated. The factors were the different sonication energies applied to the GO (Shear Mixing, 1.5 kJ/ml, 3 kJ/ml and 6 kJ/ml), the …

Balsa Bridge, Caleb T. Lovett

All Undergraduate Projects

The problem presented throughout this report was to create a small-scale bridge made entirely out of balsa wood and glue, that could withstand substantial force, as well as perform a lifting/lowering cycle. Other requirements associated with the bridge were properties of weight, deflection, size, and shape. This problem presented a challenge that tested the mathematical side of engineering, being strongly reliant on statics, mechanics of materials, and mechanical design analyses.

To approach this problem, the first step was to complete in depth calculations of the chosen design. With this done, manufacturing and assembly was able to be completed. With a …

Hempcrete Curtain Walls, Anh Bui

2024 Awards for Excellence in Student Research and Creative Activity - Documents

This research aims to scrutinize the performance, durability, and viability of hempcrete in curtain wall applications—an exploration critical to advancing sustainable construction practices. Comprising hemp hurds and lime binders, hempcrete stands as an emerging sustainable building material with promising ecological benefits. Despite its potential, there exists a notable research gap concerning its application in curtain walls, which demand rigorous structural and weatherproofing standards. The primary objective is to subject full-scale hempcrete curtain wall assemblies to ASTM standard test methods, comparing their performance with conventional materials like stone and glass. The research hypothesis posits that hempcrete will exhibit satisfactory strength, fire …

Predicting Compressive Strength Of Concrete Incorporating Fly Ash, Blast Furnace Slag, And Superplasticizer Using Machine Learning Techniques, Muhammad Faisal Yaqub

2024 REYES Proceedings

Concrete is the second most essential element in the construction industry, and its strength requirements vary based on the specific conditions of each project. However, determining the compressive strength of concrete involves laboratory tests, which wastes a lot of time and money. Researchers have developed machine learning models that predict the compressive strength of cement-based concrete having various mixes. In this research, the compressive strength of concrete incorporating fly ash, blast furnace slag, and superplasticizer is predicted using different machine learning models, namely, Linear Regression, Random Forest Regression, Decision Tree Regression, Extreme Gradient Boosting, Light Gradient Boosting, AdaBoost, and CatBoost …

Investigation Of Bone Structure And Composition Differences In Osteofibrous Dysplasia And Neurofibromatosis Type 1, Farzaneh Fereidouni

Material Science and Engineering Dissertations - Archive

Abstract

Investigation of Bone Structure and Composition Differences in Osteofibrous Dysplasia and Neurofibromatosis Type 1

Farzaneh Fereidouni, Ph.D.

The University of Texas at Arlington, 2024

Supervising Professor: Harry F. Tibbals

Bone genetic diseases such as Osteofibrous Dysplasia (OFD) and Neurofibromatosis type 1 (NF1) present significant challenges, particularly in children, due to their effects on skeletal homeostasis. This study aims to apply advanced material analysis to elucidate the biological disparities associated with OFD and NF1 bone dysplasia and contribute to developing diagnostic protocols and remediation approaches for these and similar bone disorders.

By employing various analytical methods, including analysis of mineral-to-matrix …