Civil Engineering Commons^™

Research Status And Prospects Of Monitoring Technology For Large-Span Cable-Stayed Bridges Based On Machine Learning, Liu Guoliang, Liu Guokun, Yan Donghuang, Wang Wenxi, Wang Qishun

Journal of China & Foreign Highway

Machine learning and intelligent optimization algorithms have been increasingly applied to construction and health monitoring of long-span cable-stayed bridges. Based on the construction history of cable-stayed bridges both domestically and internationally, an overview of the origin and development process of cable-stayed bridges was provided. Firstly, from the perspective of the entire life cycle of bridges, bridge monitoring was divided into construction period monitoring and operation period monitoring. The applications of mainstream construction monitoring methods in large cable-stayed bridge projects were elaborated, and the specific composition of bridge health monitoring systems was clarified. Secondly, the basic principles of several machine learning …

Effect Of Rheology Modification On Fiber Orientation And Dispersion In 3d-Printed Ultra-High-Performance Concrete, Haodao Li, Alfred Addai-Nimoh, Seongho Han, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The extrusion process in 3D concrete printing (3DCP) facilitates horizontal alignment of steel fibers along the printing direction, thus enhancing the load-bearing capacity of printed elements. However, such shear-induced fiber alignment is highly sensitive to rheological properties. This study investigates how variations in dynamic yield stress (τd) and plastic viscosity (μ), influence the extrudability, fiber orientation and dispersion, and anisotropic mechanical behavior of ultra-high-performance concrete (UHPC). Five viscosity-modifying agent (VMA) types were incorporated at two content levels to modify the rheology of printable UHPC. Results showed that moderate VMA additions improved printability, whereas excessive contents markedly increased τd and μ; …

How Does Competitive Adsorption Between Vma And Pce Influence Yield Stress Of Cement Paste? A Novel Insight From Interparticle Forces And Percolation Threshold, Huamin Sun, Le Teng, Xiaohan Yu, Xin Shu, Zhangli Hu, Jiaping Liu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Viscosity modifying admixture (VMA) and polycarboxylate superplasticizer (PCE) are often combined to optimize rheological properties of cement-based materials. However, the competitive adsorption of these complex admixtures can greatly influence rheological properties. Many studies have investigated the variation of yield stress due to competitive adsorption between VMA and PCE; but the mechanisms are not fully understood. This study aims to shed a new light on this question in cement paste systems prepared with low water-to-binder ratios of 0.16–0.30. The competitive adsorption of VMA and PCE was quantitatively assessed using the Total Organic Carbon and Ultraviolet-Visible Spectroscopy measurements. The effect of competitive …

Transforming Dredged Sediment Into Reactive Clay: Critical Review Of Calcination, Reactivity, And Sustainable Valorization As Supplementary Cementitious Material, Seongho Han, Sanghwon Wi, Koochul Ji, Keun Hyeok Yang, Farshad Rajabipour, Kamal H. Khayat, Jinyoung Yoon

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Dredged sediment (DS) is generated worldwide in large volumes through routine port and waterway maintenance, yet its disposal presents environmental and economic challenges. Recently, calcined dredged sediment (CDS) has emerged as a supplementary cementitious material (SCM), offering a viable alternative to traditional SCMs, such as fly ash and slag cement. This review synthesizes current knowledge on the physical, chemical, and mineralogical characteristics of raw DS and pretreatment strategies aimed at dewatering, organic matter removal, and contaminant stabilization. The effects of calcination on the production of reactive amorphous aluminosilicates are also discussed. Emphasis is placed on physicochemical changes revealed by experimental …

Low-Carbon Concrete For Sustainable Construction: A Comprehensive Review Of Performance Characteristics, Implementation Challenges, And Decarbonization Pathways, Fazel Azarhomayun, Jingjie Wei, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reducing the carbon footprint of concrete has become a central objective in sustainable construction. Low-carbon concrete (LCC), developed primarily through clinker reduction, supplementary cementitious materials, and alternative binder strategies, offers a promising route for lowering embodied emissions while maintaining the performance requirements of structural concrete. This comprehensive review consolidates the current state of knowledge on LCC, identifies critical research and implementation gaps, and examines its material composition, mixture-design methodologies, performance characteristics, structural applications, implementation challenges, and decarbonization pathways. Single-SCM systems have been reported at clinker-replacement levels approaching 50%, although durability at these replacement levels, particularly carbonation resistance, remains system- and …

Recent Advances In The Rheological Properties Of Ultra-High-Performance Concrete: A Critical Review, Le Teng, Kamal H. Khayat, Jiaping Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ultra-high-performance concrete (UHPC) with adapted rheology continues to attract interest considering the requirement for novel processing techniques such as self-consolidating, pumping, spraying, and three-dimensional (3D) printing. The rheology of UHPC is complex due to its high solid volume fraction, low water content, and wide range of constituent materials that affect its flow properties. This work provides guidance for tailoring the mixture proportioning of UHPC to secure proper rheological properties and performance of UHPC for various applications. In the first part of this work, key physical, physicochemical, and chemical factors that can affect the rheological properties of UHPC are discussed. Rheological …

An Analytical Framework For Quantifying Urban And Community Resilience To Natural Hazards From Cell-Phone Gps-Location And Traffic-Flow Data, Georgios Chatzikyriakidis

Civil and Environmental Engineering Theses and Dissertations

Urban areas are increasingly exposed to natural hazards while accommodating a growing share of the global population, yet a consistent science-based framework for quantifying urban and community resilience remains lacking. This dissertation develops a physics-based analytical framework grounded in statistical mechanics and the quantitative theory of Brownian motion. A city is conceptualized as a complex medium in which citizens move analogously to Brownian particles within a viscoelastic environment, influenced by socioeconomic interactions and infrastructure functionality.

A central premise is that urban resilience, interpreted as engineering resilience (an outcome), can be quantified through a single metric: the mean-square displacement MSD=⟨r²(t)⟩, of …

Computer Vision And Machine Learning Approaches For Defect Detection In 3d-Printed Cementitious Materials: A Systematic Review, Muhammad Ali Musarat, Ruben Paul Borg, Jingjie Wei, Carl James Debono, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

3D printing is evolving at a fast pace in both the manufacturing and construction sectors. These advancements can greatly benefit these industries. However, the 3D printing of concrete structures presents some challenges due to defects in the 3D concrete printed elements. Hence, this study systematically reviews Artificial Intelligence (AI)-driven techniques, such as Computer Vision and Machine Learning, to identify surface defects that can occur in 3D-printed cementitious material structures. The adopted methodology was the PRISMA statement with the aim of reporting the systematic review and meta-analysis. Two well-known databases, Web of Science and Scopus, were utilised for data extraction of …

Enameling Coating Of Pipes: Thermal Proprieties And Corrosion Tests, Signo Reis, Genda Chen, Mike Koenigstein, Liang Fan

Materials Science and Engineering Faculty Research & Creative Works

Enamel coating on pipelines can be done in several ways such as the wet process, plasma spray, and electrostatic process. Wet process requires little capital expenses and provides an acceptable finish for industrial applications particularly when the part to be coated is small. Electrostatic process of enamel powder is most promising to coating large pipelines in field conditions. The enamel coating applied by the electrostatic process is very consistent and smooth since each particle is glass only. However, the powder is very fragile until fired and the charge retention is lowered in high humidity conditions. Coupons cut from a full-size …

Toward Sustainable 3d Printable Cementitious Materials: Low-Carbon Design With Fiber Reinforcement, Nima Mahmoudzadeh Vaziri

Miners Solving for Tomorrow Research Conference

3D printing of cementitious materials, as an emerging construction technology, faces challenges in both mechanical performance and sustainability. Conventional mixture designs rely on high cement contents, leading to increased CO2 emissions, while printed elements often exhibit brittle behavior with limited crack resistance and reduced post-cracking performance. This study investigates the development of low-carbon 3D printed cementitious composites using environmentally friendly supplementary cementitious materials (SCMs) and fillers, combined with fiber reinforcement to enhance mechanical performance. Locally available SCMs and fillers were incorporated to significantly reduce cement content (>40%) and improve sustainability. Fiber reinforcement was introduced to mitigate brittleness and enhance …

Effect Of Curing Duration On Bridge Deck Concrete Performance, Zhaniya Omarova

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

This study evaluates the influence of curing duration on the performance of bridge deck concrete and investigates the feasibility of reducing curing periods without compromising structural and durability properties. Two concrete mixtures, a standard Nebraska Department of Transportation (NDOT) bridge deck mix (47BD) and an optimized reduced-cement-content mix (O47BD-R100), were evaluated under multiple curing durations Fresh, early-age, mechanical, durability, and shrinkage properties were assessed to characterize the effect of curing on concrete behavior. Internal relative humidity and temperature were monitored using embedded sensors to investigate moisture diffusion and its role in shrinkage development for lab specimens and full-scale slabs.

Results …

New Insights Into Dynamic Evolution Of Colloidal Network Structure During Early-Age Hardening Of Cementitious Materials, Hengrui Liu, Kaiyin Zhao, Shipeng Zhang, Hanghua Zhang, Shuangshuang Liu, Lucen Hao, Hongyan Ma, Kamal Khayat, Chi Sun Poon

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The evolution of microstructure in cementitious materials during their transition from fluid to solid state plays a critical role in determining their ultimate mechanical strength and overall performance. This hydration stage primarily involves a dynamic densification process occurring within the colloidal network. However, the field of cement-based materials currently lacks a comprehensive theoretical framework and associated parameters capable of effectively characterizing the specific structural regions within this network. In this study, we propose an Improved Particle Linkage (IPL) theory for describing the strength, types, and quantities of particle linkages within colloidal network. The IPL theory classifies the internal network structure …

Development Of A Novel Innovative Umbrella Falsework System For Concrete Slabs, Abdelazem Hashim

Theses and Dissertations

Formwork is one of the major elements that contribute to the cost and duration of concrete building projects. This is why optimizing such an element can lead to huge savings to all parties involved in the construction projects. With contractors facing huge challenges in such a competitive industry and employers seeking the least price and least duration for their projects, contractors are constantly under the obligations of finding the best alternatives to deliver their projects in terms of both time and money. Therefore, the main aim of this research project is to develop a falsework system, where the falsework system …

Advances And Challenges In Nano-Modified Cementitious Composites: Mechanisms, Dispersion Strategies, And Impact On Mechanical Properties, Fatemeh Mohammadi Ghahsareh, Pengwei Guo, Nusrath Jaha, Yi Bao, Kamal H. Khayat, Weina Meng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Nanomaterials are increasingly utilized to enhance the mechanical properties, durability, and functionality of concrete materials but face challenges such as agglomeration and uneven dispersion in cementitious systems, which can offset the intended improvements. This paper reviews the advances and challenges associated with nano-modified cementitious composites, elucidating fundamental mechanisms and highlighting strategies for overcoming the challenges through experimental and computing techniques. The reviewed contents include (1) the classification of nanomaterials commonly used in cementitious systems and the mechanisms through which they enhance the mechanical properties of cementitious composites; (2) challenges of nanomaterials such as agglomeration in water, re-agglomeration in cementitious systems, …

Compression Forming Of Basic Oxygen Furnace Slag-Gypsum Blocks: Performance Enhancement And Environmental Assessment, Fengyi Zhang

Student Works (2020-2029)

The construction industry plays a crucial role in global development but faces significant environmental challenges, particularly CO2 emissions from cement production. Gypsum blocks provide a sustainable alternative to traditional cement concrete blocks. However, the low mechanical strength and water resistance of gypsum materials limit the widespread adoption of gypsum-based materials in the construction industry. This study initially produced gypsum-based blocks using compression forming, adding supplementary cementitious materials (SCMs), and subjecting accelerated carbonation curing (ACC). It was found that compression forming addressed the shortcomings of traditional block manufacturing (high energy consumption and long production time), and the addition of SCMs generated …

Crack Propagation Behavior Of Polyurethane Grouting Sma Asphalt Mixtures, Ji Guoqi, Ma Hui, Zheng Junqiu, Huang Yujie

Journal of China & Foreign Highway

To reveal the influence me chanis m of polyurethane grouting on the crack propagation behavior of SMA-13 asphalt mixtures, this paper first conducted a semi-circular bending (SCB) test to validate the effectiveness of the PFC2D discrete element model, which was employed to simulate the microscopic responses of mixtures under different notch positions and grouting conditions. The analysis focused on load-displacement curves, crack propagation paths, crack number evolution, and force chain distribution characteristics. The results indicate that polyurethane grouting significantly increases the peak load and peak displacement of the specimens, thereby enhancing the fracture load-bearing capacity and deformation tolerance, with the …

Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The injection of carbon dioxide (CO₂) into cementitious systems has emerged as a promising approach to enhancing sustainability in concrete production. This study explores the impact of CO₂ injection on the rheological behavior, structural build-up, and particle size evolution of cement paste by systematically varying the water-to-cement ratio (w/c) (0.35, 0.4, and 0.5) and CO₂ concentration (0.06, 0.28, and 0.84 mol). Rheological analysis revealed a significant increase in initial yield stress with CO₂ injection. Using the Modified Bingham model, yield stress increased by 72 % and 150 % for 0.28- and 0.84-mol CO₂, …

Effects Of Eogo In Metakaolin-Based Geopolymer, Chaewon Lee, Hoyoung Lee, Jinwoo An, Boo Hyun Nam

Civil Engineering Faculty Publications

Geopolymer concrete uses a geopolymer binder instead of traditional Portland cement; thus, it reduces carbon emissions by a significant amount. In this study, Edge-Oxidized Graphene Oxide (EOGO), a carbon-based nanomaterial, was added into a metakaolin-based geopolymer, and its effect on the mechanical and rheological properties of the mixture was investigated. EOGO was added into the mixture at 0% (control), 0.1%, 0.5%, and 1% of the metakaolin mass. Several experiments were conducted to characterize the properties of the metakaolin–EOGO (MKGO) geopolymer, including its compressive strength, free–free resonance column (FFRC), void content, water absorption, setting time, flow, and rheology. It was found …

Influence Of Mixing Duration And Absorption Characteristics Of Superabsorbent Polymers On The Fresh And Hardened Properties Of High-Performance Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the combined influence of superabsorbent polymers (SAPs) with distinct absorption kinetics and extended mixing sequences on the rheological, mechanical, and transport properties of high-performance concrete (HPC). Two SAPs—an ionic acrylamide-co-acrylic acid copolymer (SAP-P) and a non-ionic acrylamide polymer (SAP-B)—were incorporated at an internal curing level of 100%. The impact of extended mixing times (3, 5, and 7 min) following SAP addition was systematically evaluated. Results showed that longer mixing durations led to increased superplasticizer demand and higher plastic viscosity due to continued water absorption by SAPs. However, yield stress remained relatively stable owing to the dispersing effect …

A Review On The Use Of Salt And Sugar As Natural Admixtures In Concrete, Noura A. Yassine, Lelian W. Elkhatib, Adel Elkordi, Mohammed Sonebi, Jamal Khatib

BAU Journal - Science and Technology

Due to the large increase in construction nowadays, the focus on the reduction of waste in the environment and saving cost becomes crucial. This issue, if solved, will conserve natural materials and make an eco-friendly environment. According to this, the use of natural materials, specifically in concrete/mortar, will shape a green and sustainable environment. One of the most used materials in construction is concrete where some additives like accelerators and retarders are added in order to enhance and modify some properties of concrete. These additives are beneficial and important to be used specifically in case of different weather conditions. Weather …

Investigating The Properties Of Eco-Bricks Composed Of Sawdust, Bamboo, And Varying Composition Of Sugarcane Bagasse Ash And Portland Cement, Wilfred Victor C. Marasigan, Julia Sophia Antonia S. Encarnacion, Czyrus Michael A. Bajeta, Alijah F. Gonzales, Juan Carlo T. Gumangan

Sinaya: A Philippine Journal for Senior High School Teachers and Students

With the construction industry contributing nearly 40% of global greenhouse gas emissions, there is a growing need for innovative and sustainable building materials. This research investigates a new eco-friendly concrete brick incorporating sugarcane bagasse ash (SCBA), sawdust, and bamboo fibers. Three eco-brick mixtures, each containing 2% bamboo fiber and 10% sawdust by weight but with varying proportions of Portland cement (PC) and SCBA, were tested against a standard brick for compressive strength, flexural strength, and water absorption. The optimal mixture, with 2% bamboo fiber by weight, 10% sawdust by weight, 85% PC, and 15% SCBA, exhibits compressive and flexural strength …

Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-consolidating earth concrete (SCEC) addresses the long construction process of conventional earthen constructions and their structural limitations, while further efforts are needed to enhance its sustainability. This study explores the development of a kaolinite-based self-consolidating earth paste (SCEP) due to their blended powder system, incorporating raw and treated (calcined and ground-calcined) kaolinite under various activation techniques, such as water hydration, sodium hexametaphosphate (NaHMP), and sodium hydroxide (NaOH) activation. The synergistic effect of calcination and mechanosynthesis on rheological, mechanical, structural, and microstructural properties of SCEP were investigated. Mechanically treated kaolinite increased yield stress, plastic viscosity, storage modulus evolution, and build-up index, …

Incorporating Recycled And Repurposed Plastic Into 100% Reclaimed Asphalt Pavement, Basant Bhatt

Graduate Theses and Dissertations (2019 - present)

The increasing awareness of sustainability in the asphalt industry has driven the use of recycled materials like reclaimed asphalt pavement (RAP) and waste plastic. This study examines the incorporation of recycled polypropylene (rPP), recycled high-density polyethylene (rHDPE), and recycled low-density polyethylene (rLDPE) at 0.3%, 0.6%, and 0.8% dosages into 100% RAP, along with the warm mix asphalt additive Evotherm® P25. Laboratory tests were conducted to evaluate the mechanical and durability performance of the modified asphalt mixtures while rutting and fatigue life were evaluated using mechanistic-empirical (ME) analysis in PerRoad software. Both plastic type and dosage had a statistically significant impact …

Evaluation Of Chloride Diffusion In Concrete Using Bulk Diffusion Test And Scanning Electron Microscopy, Payton Davis

Doctoral Dissertations and Master's Theses

Reinforced concrete is one of the most widely used construction materials in the world with many bridges and other major infrastructure consisting of such structural elements. A primary concern impacting the durability of concrete is chloride penetration in aggressive environments such as marine or coastal areas. In such environments, chloride ions can penetrate into the pores of concrete leading to the corrosion of embedded steel reinforcement which compromises the structural integrity of concrete. To investigate the issue, a comprehensive experimental program was designed and implemented which involved the preparation and testing of 31 different concrete mixes, each incorporating varying proportions …

Innovative Design Methodology For Durable Open-Graded Friction Course Asphalt Mixtures, Anas Abualia

LSU Doctoral Dissertations

Open-graded friction course (OGFC) is a thin asphalt mixture surface layer with a high percentage of coarse aggregates and high interconnected air voids, which provides improved skid resistance, visibility, and decreased pavement-tire noise. However, construction personnel at DOTD reported that conventional OGFC mixtures have short service life (raveling distress). Further, their structural contribution to the pavement structure is commonly neglected and designed only for functionality purposes.

The objective of this study was to develop a rational mix design methodology to improve the durability of OGFC asphalt mixtures. Specific objectives are to: (1) conduct a rheological and chemical characterization of polymer-, …

Underlying Mechanisms Of The Effect Of Microfines Of Manufactured Sand On Non-Linear Structural Build-Up Of Cement Paste, Jiang Zhu, Jiaping Liu, Kamal H. Khayat, Xin Cheng, Wei Zhao, Zhen Li, Xin Shu, Yongbo Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The rheological properties of cement-based materials made with manufactured sand vary with the content and physio-chemical properties of microfines in the sand. However, the evaluation of rheological properties regarding the structural build-up at early-age hydration remains challenging for the cementitious materials prepared with different manufactured sands, due to complicated underlying structuration mechanisms. This paper studies the effect of disparate microfines of different manufactured sands on the non-linear growth of static yield stress of cement pastes at rest. The paste mixtures were prepared with 0.40 and 0.275 water-to-cement mass ratio (W/C) and had a fixed mini-slump flow of 240 ± 5 …

Enhancing Road Performance With Void Reducing Asphalt Membrane, Tim Zahrn, Todd Thomas, Randy Miller

Purdue Road School

This presentation will discuss how using the technology of a Void Reducing Asphalt membrane can improve performance of our Asphalt Pavements by creating a more durable asphalt surface that resists cracking and reduces permeability. Void Reducing Asphalt Membrane (VRAM) Specifications: VRAM reduces voids in longitudinal joints, which improves the longevity of a quality road surface. INDOT has already required VRAM on certain road designs. We will review the current specifications for VRAM and outline specifications that may update with the technology. We will also discuss the Impact of Rumble Strips on Longitudinal Joint Performance. The session will also highlight how …

Effect Of Shrinkage-Mitigating Materials, Fiber Type, And Repair Thickness On Flexural Behavior Of Beams Repaired With Fiber-Reinforced Self-Consolidating Concrete, Jingjie Wei, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

While self-consolidating concrete (SCC) has emerged as a highly effective approach for the repair of concrete structures, there have been few investigations regarding the effect of the combination of different fiber and shrinkage-mitigating material types (shrinkage-reducing admixture, SRA; superabsorbent polymer, SAP; and expansive agent, EA) on the flexural behavior of repaired structures. This study aims to explore the influence of three different shrinkage-mitigating materials (1.25%–2.5 % SRA, 4%–8% EA, and 0.2%–0.4 % SAP), four fiber types (two macro synthetic fibers, MSFA and MSFB; 5D hooked steel fibers, 5D; a combination of 80 % 3D hooked steel +20 % short steel …

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 …

Flexural Post-Cracking Performance Of Macro Synthetic Fiber Reinforced Super Workable Concrete Influenced By Shrinkage-Reducing Admixture, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Most literature has focused on the effect of shrinkage-reducing admixture (SRA) in shrinkage mitigation resistance of concrete. This study aims to examine the impact of SRA on the efficiency of macro synthetic fibers (MSF) in enhancing the flexural post-cracking behavior of fiber-reinforced super workable concrete (FR-SWC). A comparative analysis of the influence of fiber combinations on the flexural post-cracking behavior of beams is also included. Results showed that a higher dosage of SRA, particularly at 5 % by mass of binder, had a noticeable negative impact on flexural post-cracking performance of beams while exhibiting positive effect on workability and shrinkage …