Civil and Environmental Engineering Commons^™

Effect Of Antioxidant Additives And Recycling Agents On Performance Of Asphalt Binders And Mixtures – Phase Ii, Nitish R. Bastola, Muhammad Ahmad, Mahdieh Khedmati, Jamilla Teixeira, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

The use of reclaimed asphalt pavement (RAP) in combination with recycling agents (RAs) (i.e., rejuvenators or softening agents) has gained significant attention from the pavement industry as a sustainable pavement solution, reducing the carbon footprint of manufactured products through the conservation of energy and reduction on the use of raw materials. Current research has found that RAs can improve RAP recycled asphalt mixture’s cracking resistance, while being capable of maintaining their rutting resistance. However, there are some concerns about the effect of RAs on the moisture damage resistance and the long-term performance (aging) of these additives. The current need is …

Development Of Multifunctional Wood Composites With Integrated Phase Change Materials For Enhanced Thermal Management, Self-Healing, And Sustainability., Emmanuel Igbokwe

LSU Master's Theses

Abstract

This study focused on incorporating self-healing, flame retardancy, and energy harvesting capabilities into the wood composite to contribute to more sustainable and energy-efficient building practices. Oriented strand board has been widely used as sheath for roofing or dry walls in residential buildings. Residential buildings account for a large portion of energy consumption. Therefore, an oriented strand board with energy harvesting capability is highly desired. Additionally, flame retardancy and damage self-healing and end-of-life recycling are also critical features for buildings.

In this study, we prepared a novel oriented strand board by constructing sandwich structures. The face sheets of the sandwich …

Building Services Engineering November/December 2024

Building Services Engineering

No abstract provided.

Semi-Annual Progress Report #15, Missouri University Of Science And Technology

Semi-Annual Progress Reports

No abstract provided.

2017-2024 Emerging Technologies And Milestone Achievements Toward Automated Bridge Inspection And Maintenance, Genda Chen

INSPIRE Archived Webinars

Main hardware and software systems developed in the INSPIRE University Transportation Center from 2017 to 2024 will be presented. Their characteristic parameters, operation procedures, performance metrics, advantages over the state of practice, and application limitations will be summarized. These systems include, but not limited to,

 Flying and climbing robots for high-quality data collection from remote sensing and nondestructive testing,

 Explainable artificial intelligence and machine learning for element segmentation and defect classification,

 3D reconstruction and digital twins for virtual inspection,

 Framework for the probability of detection for various defects and damage from in-situ sensors,

 Defect detection, …

Urbanization And Urban Sprawl In The Post-Colonial Era Douala City, Cameroon, Sylvia Munisi

Tanzania Journal of Engineering and Technology (TJET)

The history of the port city of Douala spans pre-colonial period, colonial period of the Germans and French occupation, the post-colonial era and the contemporary situation with continuous occupancy of the coastal environment. This article looks at the relationship between the history of the city of Douala to the resulting urban situation focusing on governance structure as well as rapid urbanization. The findings show that governance structure allowing for a duality of modern political system and traditional cultural system of kingships and chiefdoms has an effect to the resulting urban sprawl. Moreover, rapid urbanization under this condition has an overall …

The Use Of Locally Available Materials Towards Urban Planning For Sustainable Construction: The Case Of Gondar-Ethiopia, Kidist Dereje

Tanzania Journal of Engineering and Technology (TJET)

The city of Gondar in northern Ethiopia has a rich history that is connected to urban planning and construction. From the era of the Fasiledes that built masonry castles, Italian colonialism that zoned the city on racial boundaries and the post-colonial planning that wanted a more global standard, Gondar has been subjected to different planning and construction methods. This evolution however, has brought about challenges related to the sustainability of the construction industry and the communities within the city. This paper analyses the relationship between urban planning and use of local construction materials to attain sustainable development of the city. …

Transport Mobility Analysis For Informal Settlements In Dar Es Salaam, Tanzania, Fatma Kassim Mohamed

Tanzania Journal of Engineering and Technology (TJET)

Dar es Salaam is one of the world’s fastest growing cities and is expected to be the third largest by 2100 with a population of 76 million. Dar es Salaam city is made of multiple neighbourhoods that are very diverse in terms of socio-economic status, gender, age and prevalent activities. One of the biggest challenges facing the city of Dar es Salaam is urban sprawl due to informal settlements that in turn leads to very long travel time and hinders equal mobility and accessibility of labour and goods. This study found that the current mobility vision for Dar es Salaam …

Relationship Between Historic Evolution, Urbanization And Mobility In Ibadan, Nigeria, Aisha Adams

Tanzania Journal of Engineering and Technology (TJET)

Ibadan is said to be the biggest indigenous city in Nigeria with a population of about 4.04 million, making it the third largest city in the country after Lagos and Kano. Since its founding in 1829, Ibadan has experienced urban evolution that is mostly unguided. With its high fertility rate, population growth and rural-to-urban migration, Ibadan has experienced significant urban sprawl that has resulted in challenges in urban mobility especially to the lower-income earners. This study looks at the relationship between urban planning, urbanization and mobility in the city of Ibadan. The study found that lack of integrated land use …

Investigating The Relationship Between History, Urbanization And Wealth Gap In Johannesburg, South Africa, Abdallah F. Kaamah

Tanzania Journal of Engineering and Technology (TJET)

The city of Johannesburg is the largest city in South Africa and named as one of the economic drivers of the country. However, the city has the widest wealth gap in the country. This article examines the relationship between historical occurrences, urbanization, and the resulted wealth disparity in Johannesburg and look at the mitigation measures. The findings point to the wealth disparity in the city as a multifaceted problem influenced by historical, urbanization, and political variables. Comprehensive and multifaceted policy initiatives are required to address the structural causes of inequality and the urgent needs of vulnerable populations to close the …

The Influence Of Planning And Architectural Styles On The Sustainability Of The City Of Kumasi, Ghana, Elom Ayeke

Tanzania Journal of Engineering and Technology (TJET)

The city of Kumasi that was once dubbed the ‘Garden City of West Africa’ was founded in the late 17th century and served as the seat of government for the medieval Greater Asante Union. It later served as a commercial hub for the British Colony after undergoing massive transformation in the first two decades of the 19th century. Post-independence, the city went through various urban planning projects that mostly targeted social development. The architecture of Kumasi has also been changing through different periods of its history. This article examines the relationship between the evolution of the city of Kumasi through …

Impacts Of Phosphate And Residual Free Chlorine On The Precipitation, Stability And Dissolution Of Lead Corrosion Products, Yao Ma

McKelvey School of Engineering Graduate Student Theses & Dissertations

Lead release from lead pipes into drinking water is a critical threat to public health. Orthophosphate addition is an established method of controlling lead concentrations in tap water. Many phosphate-based inhibitors currently used by utilities are blends of orthophosphate and polyphosphate. Orthophosphate can limit lead release from pipes by forming low-solubility lead phosphate solids on pipe inner surfaces. In contrast, polyphosphate can accelerate lead release by forming soluble lead-phosphate complexes. Due to the potential conversion from polyphosphate to orthophosphate in the distribution system and to complex dynamics of water chemistry in lead service lines (LSLs), the net impact of a …

Green Cities And Transportation, Ariadna Reyes-Sanchez, Soheil Sharifi-Asl, Ladan Mozaffarian

Mavs Open Press Open Educational Resources - Archive

Green Cities and Transportation examines the significance of sustainable transportation projects for mitigating greenhouse gas emissions while supporting transportation equity for vulnerable commuters. The book examines insightful case studies from around the world that can serve as a reference for sustainable transportation initiatives in the U.S. It is organized into three sections: 1) Sustainability, Transportation Equity, and Planning, 2) Case Studies and Lessons from the North and South, and 3) Greenhouse Gas Emissions, Cities, and Mobility.

Transportation Land Use Modeling And Policy, Qisheng Pan, Soheil Sharifi-Asl

Mavs Open Press Open Educational Resources - Archive

Transportation Land Use Modeling and Policy provides a comprehensive introduction to land use and transportation models, offering a detailed exploration of integrated modeling approaches through case studies and real-world examples. It begins with an overview of current transportation planning issues and moves into several chapters dedicated to integrated land-use and transportation models, including Land Suitability, Lowry-type models, and more recent approaches such as MEPLAN and PECAS. The book also examines traditional travel demand modeling (TDM), giving readers a solid foundation in the subject.

Editorial: Advances In Ecological Environment Changes In Coastal And Estuarine Waters In Response To Hydrodynamic Variability, Jiayi Pan, Yeqiang Shu, Zhe-Wen Zheng, Adam T. Devlin, Majid Nazeer, Andrew M. Fischer

Civil and Environmental Engineering Faculty Publications and Presentations

Over the past few decades, coastal and estuarine ecological environments have undergone significant and rapid transformations, driven by a range of factors, with the variability in hydrodynamic conditions being one of the most prominent (Elliott et al., 2019; Statham, 2012; Da et al., 2024). These dynamic forces influence water movement, sediment transport, and nutrient cycling, all of which are critical components affecting the health and stability of these ecosystems (van Vliet et al., 2023; Li et al., 2023). Consequently, understanding and interpreting hydrodynamic processes in coastal and estuarine waters are fundamental to unraveling the mechanisms behind ecological changes. This task …

Treatment Methods Of Unstable Expansive Soil Slope Excavation In Overlying Rock Layer In Alpine Region, Shi Xiaobo, Cui Guangyan, Mou Chao, Wen Ye, Xie Feng, Fu Xiaoyang

Journal of China & Foreign Highway

To deeply study the treatment method for instability of highway cutting slope under the condition of expansive soil overlying rock layer in an alpine region，the comprehensive treatment method of unstable slope under this bad geology was put forward based on the unstable slope project of Zhangbei‒Shangyi Expressway.The governance protection structure consisted of a rigid protection system，drainage system，thermal insulation system，flexible protection system，and waterproof system.The rigid protection system was an anti-slide pile setting at the height of 1/3 of the first grade slope，of which parameters were calculated by cutting the slope of the rock layer in the unstable area to reduce the …

Treatment And Measurement Of Water Inrush During Highway Tunnel Construction, Wang C Haojie, Feng Zhihua, Fan Haobo

Journal of China & Foreign Highway

As a special geological condition of highway tunnels，water inrush will cause difficulties in engineering construction technology and management.Unnecessary disputes and management difficulties will emerge when different construction units hold different views about the treatment measures of water inrush，which leads to distributed provisions in the specification and a long treatment period.In view of key problems about the water inrush during highway tunnel construction，including water inrush treatment concept，investigation and estimation，measurement and pricing，and on-site confirmation，this paper systematically sorted out the current regulations and other guiding documents and investigated the treatment methods of tunnel water inrush and reverse slope pumping in China ’s highway …

Review Of Evaluation Methods For Mixing Workability Of Asphalt Mixture, Dong Fuqiang, Zu Yuanzhe, Yu Xin, Chen Bei, Liu Lin

Journal of China & Foreign Highway

To clarify the evaluation methods an d research status of mixing workability of asphalt mixture， by consulting relevant research literature in China and abroad and analyzing different evaluation methods，indexes，and research findings of the workability of asphalt mixture，the applicability and evaluation effects of different workability evaluation methods were systematically summarized，and the comparative analysis and comprehensive review were made on the main influencing factors of the mixing workability.The results show that in most evaluation methods for the mixing workability of asphalt mixture，corresponding indexes are constructed to quantitatively evaluate the workability by quantifying the resistance or energy consumption in the mixing process.Besides，in some …

Research Review Of Biomass Ash As Concrete Admixture, Ma Bicong, Liang Jian, Weng Yiling

Journal of China & Foreign Highway

In order to provide a comprehensive overview of research progress in the use of biomass ash as concrete admixture，the physical and chemical properties，mechanism of action，factors affecting the production process of biomass ash，and the effects of biomass ash incorporation on the working properties，mechanical properties，and durability of concrete were studied.The results show that biomass ash has a smaller density and a larger specific surface area than traditional mineral admixture，and the total amount of active components，namely SiO2 + Al2O3 + Fe2O3 （SAF） in most biomass ashes exceeds the requirements of class F volcanic ash （≥70%）.Incorporating biomass ash can effectively improve the mechanical properties …

Compaction Characteristics Of Granular Material And Its Structural Mechanical Behavior Considering Orthotropy, Huang You, Zhang Yunbao, Liu Zhaohui, Pan Yu, Liu Zebin, Fang Ronghai

Journal of China & Foreign Highway

The orthotropy of granular materials is closely related to the compaction process and has a significant impact on the mechanical behavior of pavement structures.In this study，in order to study the effect of the compaction process on the orthotropy of granular materials，different compaction methods and compaction energies were employed to compact granular materials for pavement into specimens，and improved dynamic resilient mechanical tests were conducted.Orthotropic coefficients （α2） of typical granular materials were obtained，and the finite element method was used to conduct mechanical analysis of asphalt pavement structures considering the orthotropy of granular materials.The results show that the dry density of specimens by …

Effect Of Basalt Fiber On Strength Of Cement‑Stabilized Macadam Base, Shu Hongbo, Tang Zhengguang, Zhang Yanhong, Bu Xilian, Liang Dong

Journal of China & Foreign Highway

To study the performance of basalt fiber in improving the poor angularity of the crushed cobble base，based on the orthogonal test，this paper determined that the optimal dosage of basalt fiber in the cement-stabilized crushed cobble was 1 kg/m3 （15 mm） + 2 kg/m3 （25 mm）.Besides，unconfined compressive strength and splitting strength tests were carried out on mixtures under three working conditions including the cement-stabilized crushed cobble，cement-stabilized crushed cobble with the optimal dosage of basalt fiber，and cement-stabilized macadam （limestone machine-crushed stone ）.The results show that influenced by the aggregate angularity，the strength of the cement-stabilized macadam （limestone machine-crushed stone ） mixture is better …

Design And Simulation Of Anti‑Collision System On Independent Pile With External Composite, Liao Yuanyuan, Liu Yu, Zhu Lu, Fang Hai, Zhang Jinrui, Han Juan

Journal of China & Foreign Highway

The precise calculation of the ship-bridge collision force is necessary for the assessment of the structural safety of the bridge and the design of an effective anti-collision system.Taking the ship-bridge issue in Furong Bridge in Xiangtan City，this paper compared the collision forces from different angles and in different locations calculated through the finite element software Ansys/LS-DYNA with the results calculated through the empirical formula，thereby determining the fortification collision forces of the bridge piers.Based on the weak anti-collision ability of the bridge double-limb thin-walled pier，the paper designed and implemented a new anti-collision system combined with composite and concrete-filled steel independent piles.The …

Intelligent Recognition Technology Of Highway Cracks Based On Semantic Segmentation, Gao Liang, Rao Faqiang, Yang Zhongmin, Dai Zongsheng, Sun Hao

Journal of China & Foreign Highway

Real-time detection and timely treatment of highway cracks are crucially fundamental for vehicle safety.Rapid identification and comparison of cracks is a new method for monitoring the development and changes of geological disasters especially when they induce cracks.Therefore，this study proposed an intelligent recognition method of highway cracks based on semantic segmentation，establishing a model with dataset，neural network，calculation parameters，and evaluation indicators to rapidly identify the cracks.The results show that，firstly，when the neural network Attention U-net built in this study semantically segments highway cracks，the binary cross loss function value and accuracy rate reach 0.008 7 and 0.998 4，respectively.Secondly，compared with traditional algorithms，the semantic segmentation method shows …

Lessons Learned From 60 Years Of Pavement Trials In Continental Climate Regions Of Canada And Future Perspective, Wang Di, Li Jingxiao, Ren Xueyuan, Zhang Fan, Yuan Dongdong

Journal of China & Foreign Highway

During the early 1960 s，Canadian road authorities began using stiffer asphalt to address the issue of early rutting in the wheel track zone of asphalt pavements，which was caused by the growing traffic volumes.Pavements constructed with stiffer asphalt commonly exhibit evenly spaced transverse cracks due to the significant internal stresses caused by low temperatures and the inadequate resistance of the asphalt to cracking under such conditions.Research conducted on asphalt pavements with cracks caused by low temperatures has verified the significant impact of asphalt ’s consistency，temperature sensitivity，phase uniformity，and durability.In order to tackle the difficulties presented by the utilization of modified asphalt in …

Method Of Solving Initial Construction Cable Force Of Completed Cable‑Stayed Bridge, Xu Yufeng, Chen Si, Xie Yunfei, Zhu Mengyang

Journal of China & Foreign Highway

To solve the initial construction cable forces of a completed cable-stayed bridge，a method that combines unstressed cable length and forward-iteration is proposed.Firstly，the unstressed length of each cable is calculated according to the completed bridge state.Then，the initial cable forces are obtained by using the unstressed cable length for the forward analysis.The initial construction cable forces are adjusted by difference iteration.Finally，the initial construction cable forces are fine-tuned according to the deformation of the pylon deformation to obtain the bridge completion state that satisfies the deviation requirements.The proposed method is employed in a cable-stayed bridge with a known completion state to calculate the …

Experimental Study On Influence Of Stress Ratio On Fatigue Life Of High Strength Steel Wire, Zeng Yi, Yan Donghuang, Xu Hongsheng, Yang Ying

Journal of China & Foreign Highway

To clarify the influence of stress ratio on the fatigue life of high strength steel wire and verify the applicability of the fracture mechanics model to evaluate the fatigue life of steel wire，based on the assumption of equating wire corrosion pits to notches，fatigue tests were carried out on steel wire samples with different prefabricated notch depths at different stress ratios，and a fatigue life empirical equation considering the stress ratio effect was established.The results show that the fatigue life of the steel wire samples is significantly influenced by the stress ratio，which decreases with the increase in the stress ratio.The increase in …

Influence Of High Temperature On Large Cantilever Construction Control Of Wide Extradosed Cable‑Stayed Bridge, Zhu Haojie, Zhang Xiedong, Li Yong, Lin Yuan, Wu Di

Journal of China & Foreign Highway

In order to investigate the influence of temperature gradient on the construction of wide extradosed cable-stayed bridges in the large cantilever construction stage at high temperatures，the solar radiation and thermal boundary conditions of wide equal-height box girder were theoretically calculated，and the thermal analysis finite element model of the wide equal-height box girder was established by Abaqus.The cross-section temperature of the box girder was measured by intelligent string sensors and an infrared thermometer.The temperature gradient and its distribution of wide equal-height box girder from sunrise to sunset on a certain day in summer were calculated.The finite element model of the construction …

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 …