Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Missouri University of Science and Technology

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 511 - 540 of 7869

Full-Text Articles in Civil and Environmental Engineering

Extending The Nno Ballistic Limit Equation To Foam-Filled Dual-Wall Systems, William P. Schonberg Jan 2023

Extending The Nno Ballistic Limit Equation To Foam-Filled Dual-Wall Systems, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A key component in the quantitative assessment of the risk posed to spacecraft by the micrometeoroid and orbital debris (MMOD) environment is frequently referred to as a ballistic limit equation (BLE). A frequently used BLE for dual-wall configurations (which are commonly used on spacecraft to protect them against the MMOD environment) is the New Non-Optimum, or "NNO", BLE. In design applications where a BLE is needed for a new structural system that has not yet been tested, but resembles to a fair degree a dual-wall system, it is common practice to equivalence the materials, thicknesses, etc., of the new system …


Evaluation Of Thermal And Rheological Properties Of Phase Change Material-Incorporated Asphalt Mastic With Porous Fillers, Farshad Saberi Kerahroudi, Yizhuang David Wang, Jenny Liu Jan 2023

Evaluation Of Thermal And Rheological Properties Of Phase Change Material-Incorporated Asphalt Mastic With Porous Fillers, Farshad Saberi Kerahroudi, Yizhuang David Wang, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Incorporating phase change material (PCM) into paving materials can regulate the pavement temperature, improve the pavement durability, and mitigate the heat-island effects. In this research, porous fillers were used as the PCM carrier, and the thermal and rheological behaviors of the asphalt mastic with the PCM were evaluated. Two different carrier materials (diatomite and expanded perlite) and four types of PCMs were used in the study. The candidate filler, PCM, and proper blending ratios were determined based on the results of scanning electron microscope image analysis, the filter paper test, and the temperature sweep test. The thermal and rheological behaviors …


Rapid-Throughput Analysis Of 1,4-Dioxane In Plants By Centrifugal Sampling And Phytoforensic Analysis For Site Delineation And Assessing Enhanced Rhizodegradation, Anthony Eberechukwu Oha Jan 2023

Rapid-Throughput Analysis Of 1,4-Dioxane In Plants By Centrifugal Sampling And Phytoforensic Analysis For Site Delineation And Assessing Enhanced Rhizodegradation, Anthony Eberechukwu Oha

Masters Theses

"Owing to its broad use and environmental persistence, 1,4-dioxane (dioxane) poses a notable threat to public health and is recalcitrant to traditional remedial systems. Dioxane moves readily in an aqueous environment and is an emerging contaminant in drinking water, surface water, groundwater, and wastewater. The extent of dioxane in the biosphere is also difficult to delineate, particularly in the subsurface. Phytoremediation has demonstrated the potential for dioxane groundwater remediation. Recent findings indicate that plant-microbial symbiosis may be more advantageous for limiting potential transport and transfer into plant tissues and the atmosphere. Bioaugmentation of the rhizosphere paired with soil amendments has …


Selecting Consolidation Procedures For Making Concrete Specimens, Paige Marie Toebben Jan 2023

Selecting Consolidation Procedures For Making Concrete Specimens, Paige Marie Toebben

Masters Theses

"The goal of this research was to reevaluate ASTM C31 Standard Practice for Making and Curing Concrete Test Specimens in the Field, as well as deepen our understanding of the relationship between the consolidation process, concrete composition, and workability. An improved understanding of this area will help to reduce variability in concrete quality. The project involved evaluating the effect of different consolidation methods on concrete specimens with changing levels of workability. To do this, concrete cylinders were created with varying viscosities by adjusting the water-to-cement ratio (w/c) and water-reducing agent. More cylinders were created with varying paste volumes while keeping …


Analyzing Ground Motion Records With Cvi Fuzzy Art, Dustin Tanksley, Xinzhe Yuan, Genda Chen, Donald C. Wunsch Jan 2023

Analyzing Ground Motion Records With Cvi Fuzzy Art, Dustin Tanksley, Xinzhe Yuan, Genda Chen, Donald C. Wunsch

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper explores using Cluster Validity Indices Fuzzy Adaptative Resonance Theory (CVI Fuzzy ART) to cluster ground motion records (GMRs). Clustering the features extracted from a supervised network trained for predicting the structure damage results in less overfitting from the trained network. Using Cluster Validity Indices (CVIs) to evaluate the clustering gives feedback to how well the data is being classified, allowing further separation of the data. By using CVI Fuzzy ART in combination with features extracted from a trained Convolutional Neural Network (CNN), we were able to form additional clusters in the data. Within the primary clusters, accuracy was …


Promoting Enhanced Decision-Making And Proactive Management For Modularization In The Construction Industry Using Risk-Based Approach, Analytical Hierarchy Process, And Graph Theory, Mohamad Abdul Nabi Jan 2023

Promoting Enhanced Decision-Making And Proactive Management For Modularization In The Construction Industry Using Risk-Based Approach, Analytical Hierarchy Process, And Graph Theory, Mohamad Abdul Nabi

Doctoral Dissertations

"Modularization is an approach that can potentially mitigate many of the current construction industry’s challenges. Despite the documented advantages of modularization, the industry is still not able to capitalize on its full potential and benefits. The latter is due to the outdated decision-making models that may not reflect the multiple factors involved in modular construction, the unique source of risks associated with modular construction methods, need for continuous improvement, and complex contractual requirements and disputes. As such, the goal is to promote the use of modularization in the construction industry by enhancing decision-making and proactive risk management. The associated objectives …


2022 Scholarly Productivity Report, Missouri University Of Science And Technology Dec 2022

2022 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.


The Bridge Newsletter Winter 2022, Missouri University Of Science And Technology Dec 2022

The Bridge Newsletter Winter 2022, Missouri University Of Science And Technology

The Bridge Newsletter

-Missouri S&T CO2 research is rock solid
-Bringing circular economy to construction projects
-Ph.D. graduate wins Fellowship for solar farm protection research
-Rockne presents 2022 Mathes Lecture on ways to evolve engineering education
-Missouri S&T Ph.D. graduate wins $70,000 Laegeler Fellowship for solar farm protection research


Basalt Fibers For Underwater Fatigue Repair Of Steel Panels, Guillermo Riveros, Emad M. Hassan, Lauren Hudak, Hussam Mahmoud Nov 2022

Basalt Fibers For Underwater Fatigue Repair Of Steel Panels, Guillermo Riveros, Emad M. Hassan, Lauren Hudak, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fatigue damage is a major threat to the safety and integrity of many steel structures. Steel hydraulic structures (SHS), in particular, experience fatigue loading during operation and are exposed to harsh environmental conditions that can further reduce fatigue life through mechanisms. The traditional inspection and repair process for SHS is time-consuming and leads to economic losses. Studies investigating the behavior and advantages of using bonded carbon fiber-reinforced polymer (CFRP) to repair fatigue cracks in SHS are lacking. The main objectives of this study are to increase the bonding of CFRP, investigate the effectiveness of different fiber-reinforced polymers, and test different …


Understanding The Role Of Activated Sludge In Oxygen Transfer: Effects Of Sludge Settleability, Solids Retention Time, And Nitrification Reaction, Ken Campbell, Jianmin Wang Nov 2022

Understanding The Role Of Activated Sludge In Oxygen Transfer: Effects Of Sludge Settleability, Solids Retention Time, And Nitrification Reaction, Ken Campbell, Jianmin Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The current understanding on the oxygen transfer in activated sludge process is primarily developed based on two-phase systems, focusing only on oxygen transfer from air to water. However, this research demonstrates that activated sludge particles significantly impact oxygen transfer from air all the way to the microorganisms. Three bench-scale complete-mix activated sludge reactors, operated under the same influent loading and dissolved oxygen level but different solids retention times (SRTs), were used to develop oxygen transfer performance data as effects of different sludge property parameters. These reactors were also operated under batch modes to further validate the effect of nitrification reaction …


Final Report - Simulation Training To Work With Bridge Inspection Robots, Sushil J. Louis Oct 2022

Final Report - Simulation Training To Work With Bridge Inspection Robots, Sushil J. Louis

Project WD-3

This project aims to investigate and develop a software system that helps bridge inspectors work together with semiautonomous and autonomous robots that efficiently and effectively inspect truss bridges more thoroughly in less time. Our first project WD-2 effort developed a simulation training system for bridge inspection, enabling a heterogeneous group of simulated robots to accelerate comprehensive bridge inspections. This new project WD-3 will investigate and develop techniques to 1) map the simulated world to the real world, 2) connect simulated robots with real robots being developed in other INSPIRE projects, and 3) investigate and develop algorithms, protocols, and autonomy for …


Final Report - Developing A Robotic Simulator And Video Games For Professional And Public Training, Sushil J. Louis Oct 2022

Final Report - Developing A Robotic Simulator And Video Games For Professional And Public Training, Sushil J. Louis

Project WD-2

This project developed a simulation training software for operators to monitor and supervise autonomous robots when inspecting steel truss bridges. Since the software abstracts the command and situation visualization interface when dealing with simulated inspection robots and bridge, the same software can be connected to physical robots to control and monitor physical robots during bridge inspection. Version 1 of Simulation Training and Control (STACS) was developed and tested with two virtual bridges and one virtual climbing robot for steel truss member inspection and one virtual flying UAV for visual inspection. This version of STACS also prototyped and tested a Robot …


Optimization Of Mixture Parameter For Physical And Mechanical Properties Of Reactive Powder Concrete Under External Sulfate Attack Using Taguchi Method, Umut Bakhbergen, Chang Seon Shon, Dichuan Zhang, Jong Ryeol Kim, Jenny Liu Oct 2022

Optimization Of Mixture Parameter For Physical And Mechanical Properties Of Reactive Powder Concrete Under External Sulfate Attack Using Taguchi Method, Umut Bakhbergen, Chang Seon Shon, Dichuan Zhang, Jong Ryeol Kim, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reactive powder concrete (RPC) is defined as a cementitious composite material with an optimized size of granular constituents, very low water-to-binder ratio (w/b), pozzolanic materials like silica fume (SF), and discontinuous fiber reinforcement. RPC applications include bridge decks and girders, seismic columns, wind turbine towers, and pile foundations. Especially, a durable and robust RPC pile foundation with long service life is essential in building construction because continuous maintenance is impossible. Moreover, natural in-situ conditions such as water table, temperature, and sulfate concentration in soil to which the pile foundation is exposed are critical and related to deteriorating the pile foundation. …


Upcycling Steel Slag In Producing Eco-Efficient Iron–Calcium Phosphate Cement, Yue Ma, Yunlong Luo, Hongyan Ma, Xintao Zhou, Zhongqiu Luo Oct 2022

Upcycling Steel Slag In Producing Eco-Efficient Iron–Calcium Phosphate Cement, Yue Ma, Yunlong Luo, Hongyan Ma, Xintao Zhou, Zhongqiu Luo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In the present study, steel slag powder (SSP) was utilized as the raw material to prepare iron-calcium phosphate cement (ICPC) by reacting with ammonium dihydrogen phosphate (ADP). The influences of the raw materials (SSP/ADP) mass ratios ranging from 2.0 to 7.0 on the properties and microstructures of ICPC pastes were investigated. The compressive strengths of ICPC pastes at all ages firstly increased and then decreased with the increase of SSP/ADP, and the SSP/ADP of 6.0 gave the highest strength. Crystalline mundrabillaite and amorphous phases [i.e. Fe(OH)3, Al(OH)3 and H4SiO4] were formed as the …


Homogenous Flow Performance Of Steel Fiber-Reinforced Self-Consolidating Concrete For Repair Applications: Developing A New Empirical Set-Up, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat Oct 2022

Homogenous Flow Performance Of Steel Fiber-Reinforced Self-Consolidating Concrete For Repair Applications: Developing A New Empirical Set-Up, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, a new empirical Square-Box test was employed to evaluate the homogeneous flow performance of fiber-reinforced self-consolidating concrete (FR-SCC) under confined-flow conditions that are typical of repair applications. The Square-Box set-up consisted of a closed-circuit box, providing 2.4-m flow distance and a closed-surface cross section of 100-mm width and 200-mm height, equipped with 0 and 4 rows of reinforcing bar grids with 45-mm clear spacing. The flow performance was assessed in terms of dynamic stability and passing ability. The investigated mixtures were considered as diphasic suspensions of fiber-coarse aggregate (F-A > 5 mm) in suspending mortars containing particles finer …


Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat Oct 2022

Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the effect of individual and combined additions of CaO-based expansive agent (EA), shrinkage reducing admixture (SRA), and super absorbent polymer (SAP) on key characteristics of flowable cement paste mixtures proportioned with a water-to-cement ratio of 0.40. Of special interest is the effectiveness of these admixtures to mitigate shrinkage of cementitious materials for 3D printing. Static and dynamic yield stress, plastic and apparent viscosities, and thixotropy were evaluated at 20-min intervals up to 90 min. Compressive strength development and autogenous shrinkage were also determined. A factorial design approach was developed to evaluate the synergetic effects of the shrinkage …


Spiral Deployment Of Optical Fiber Sensors For Distributed Strain Measurement In Seven-Wire Twisted Steel Cables, Post-Tensioned Against Precast Concrete Bars, Yanping Zhu, Genda Chen Oct 2022

Spiral Deployment Of Optical Fiber Sensors For Distributed Strain Measurement In Seven-Wire Twisted Steel Cables, Post-Tensioned Against Precast Concrete Bars, Yanping Zhu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

On-time monitoring and condition assessments of steel cables provide mission-critical data for informed decision making, ensuring the structural safety of post-tensioned concrete structures. This study aimed to develop a spiral deployment scheme of distributed fiber optic sensors (DFOS) and to monitor/assess the post-tensioned force in seven-wire twisted steel cables, based on the pulse-pre-pump Brillouin optical time domain analysis. Each DFOS was placed in a spiral shape between two surface wires of a steel cable and glued to the steel cable by epoxy. Image observations were conducted to investigate the entireness and bonding condition between the optical fiber and the steel …


Characterizing And Modeling The Coupled Hydro-Mechanical Cyclic Behavior Of Unsaturated Soils Using Constant Water Content Oedometer And Direct Shear Tests, Beshoy Riad, Xiong Zhang Oct 2022

Characterizing And Modeling The Coupled Hydro-Mechanical Cyclic Behavior Of Unsaturated Soils Using Constant Water Content Oedometer And Direct Shear Tests, Beshoy Riad, Xiong Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Most transportation infrastructures are constructed on compacted soils that are typically unsaturated above the groundwater table. The soils are subjected to cyclic traffic loadings and seasonal wetting–drying cycles. Although problems associated with unsaturated soils are ubiquitous in the US, coupled hydro-mechanical analysis is rarely included in the design/analysis of transportation geosystems. This can be attributed to two main reasons: (a) there are no simple devices/methods which can be used to rapidly characterize stress–strain behavior for unsaturated soils, and (b) there is a lack of a constitutive model to study coupled hydro-mechanical cyclic behavior for unsaturated soils in a consistent way. …


Benefits And Drawbacks Of Using Multiple Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat Oct 2022

Benefits And Drawbacks Of Using Multiple Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Shrinkage mitigating strategies have been successfully used to prevent concrete cracking. Numerous studies have demonstrated the efficiency of shrinkage mitigating materials (SMM), such as expansive agent (EA), shrinkage reducing admixture (SRA), and superabsorbent polymer (SAP) on reducing shrinkage and cracking; however, few studies have addressed the limitations of using these materials. In addition, the mechanism of negative effect on microstructure and mechanical properties when these materials are used at high contents or in combinations is not well defined. This study investigates the effect of CaO-based EA, SRA, and SAP on compressive strength development, fiber pull-out strength, and shrinkage of fiber-reinforced …


A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu Oct 2022

A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Copper slag (CS), a by-product of copper smelting, is normally stockpiled, leading to wastes of resource and space as well as environment pollution. It has not been massively reutilized as a supplementary cementitious material in Portland cement due to its low reactivity. In the present study, CS is for the first time utilized as the base component to prepare an iron phosphate cement (IPC) by reacting with ammonium dihydrogen phosphate (ADP) at room temperature. The influence of the raw materials mass ratio (CS/ADP) on the microstructure and performance of IPC pastes are investigated. It is found that the compressive strength …


Studying Dynamic Pricing In Electrical Power Markets With Distributed Generation: Agent-Based Modeling And Reinforcement-Learning Approach, Gasser G. Ali, Islam H. El-Adaway, Charles Sims, J. Scott Holladay, Chien Fei Chen Oct 2022

Studying Dynamic Pricing In Electrical Power Markets With Distributed Generation: Agent-Based Modeling And Reinforcement-Learning Approach, Gasser G. Ali, Islam H. El-Adaway, Charles Sims, J. Scott Holladay, Chien Fei Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Distributed generation (DG) refers to small-scale generation resources that are located at or near end-consumers, such as photovoltaic (PV) solar systems. DG systems have become increasingly popular in recent years owing to their economic efficiency, reliability, and sustainability. However, the increasing adoption of DG is creating new obstacles for system operators due to the uncertainty in forecasting future demand. One concern is the possibility of facing a utility death spiral as a feedback loop between, on the one hand, the increasing adoption of DG and increasing electricity rates to cover generation and transmission overheads with, on the other hand, reduced …


Semi-Annual Progress Report #11, Missouri University Of Science And Technology. Inspire - University Transportation Center Sep 2022

Semi-Annual Progress Report #11, Missouri University Of Science And Technology. Inspire - University Transportation Center

Semi-Annual Progress Reports

No abstract provided.


Artificial Intelligence In Civil Infrastructure Health Monitoring—Historical Perspectives, Current Trends, And Future Visions, Tarutal Ghosh Mondal, Genda Chen Sep 2022

Artificial Intelligence In Civil Infrastructure Health Monitoring—Historical Perspectives, Current Trends, And Future Visions, Tarutal Ghosh Mondal, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Over the past 2 decades, the use of artificial intelligence (AI) has exponentially increased toward complete automation of structural inspection and assessment tasks. This trend will continue to rise in image processing as unmanned aerial systems (UAS) and the internet of things (IoT) markets are expected to expand at a compound annual growth rate of 57.5% and 26%, respectively, from 2021 to 2028. This paper aims to catalog the milestone development work, summarize the current research trends, and envision a few future research directions in the innovative application of AI in civil infrastructure health monitoring. A blow-by-blow account of the …


Common Ground Newsletter Fall 2022, Missouri University Of Science And Technology Sep 2022

Common Ground Newsletter Fall 2022, Missouri University Of Science And Technology

Common Ground

- Summer camps returned in person


Flexural Strength Of Innovative Thin-Walled Composite Cold-Formed Steel/Pe-Ecc Beams, Ahmed Sheta, Xing Ma, Yan Zhuge, Mohamed Elgawady, Julie Mills, Elsayed Abd-Elaal Sep 2022

Flexural Strength Of Innovative Thin-Walled Composite Cold-Formed Steel/Pe-Ecc Beams, Ahmed Sheta, Xing Ma, Yan Zhuge, Mohamed Elgawady, Julie Mills, Elsayed Abd-Elaal

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A detailed experimental investigation on the flexural behaviour of an innovative precast composite element combining cold-formed steel (CFS) and engineered cementitious composites (ECC) is presented in this paper. Bonding ECC to the lightweight thin-walled CFS sections enhanced the buckling, bearing, and torsional properties of the composite sections. The proposed composite system will be used as precast flexural members in framed structures with large spans or as a rehabilitation approach for corroded cold-formed and hot-rolled steel flexural members. Simply supported beams with comparatively long spans with span-to-depth ratios of 6.83 and 13.48 were installed back-to-back and tested under a 4-point loading …


Reliability Of Bridge Inspection Technologies, Glenn A. Washer Sep 2022

Reliability Of Bridge Inspection Technologies, Glenn A. Washer

INSPIRE Archived Webinars

This presentation will discuss the reliability of inspection technologies used for the condition assessment of highway bridges. Data from condition assessments are critical to asset management and decision-making. The methodologies used to assess condition are usually subjective methods, such as visual inspections, that can vary as a result of human factors and differences in training and interpretation of inspection procedures. Nondestructive evaluation technologies (NDE) are implemented on a more limited basis and rely on indirect measurements to infer the presence of damage, and these assessments are affected by environmental factors, materials variability, and limitations in the interpretation of the resulting …


Some New Insights For Inferring Diapycnal (Irreversible) Diffusivity In Stably Stratified Turbulence, Amrapalli Garanaik, Subhas Karan Venayagamoorthy Sep 2022

Some New Insights For Inferring Diapycnal (Irreversible) Diffusivity In Stably Stratified Turbulence, Amrapalli Garanaik, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

New insight for inferring diapycnal diffusivity in stably stratified turbulent flows is obtained based on physical scaling arguments and tested using high-resolution direct numerical simulation data. It is shown that the irreversible diapycnal diffusivity can be decomposed into a diapycnal length scale that represents an inner scale of turbulence and a diapycnal velocity scale. Furthermore, it is shown that the diapycnal length scale and velocity scale can be related to the measurable Ellison length scale (LE) that represents outer scale of turbulence and vertical turbulent velocity scale (w ′) through a turbulent Froude number scaling analysis. The turbulent Froude number …


Investigation On Chloride Binding Capacity And Stability Of Friedel's Salt In Graphene Oxide Reinforced Cement Paste, Wu Jian Long, Xuanhan Zhang, Gan Lin Feng, Jing Xie, Feng Xing, Biqin Dong, Jinrui Zhang, Kamal Khayat Sep 2022

Investigation On Chloride Binding Capacity And Stability Of Friedel's Salt In Graphene Oxide Reinforced Cement Paste, Wu Jian Long, Xuanhan Zhang, Gan Lin Feng, Jing Xie, Feng Xing, Biqin Dong, Jinrui Zhang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chloride binding capacity is one of the important factors affecting chloride induced rebar corrosion in reinforced concrete structures. Moreover, the stability of Friedel's salt will also affect the chloride binding capacity of cement-based materials. This study investigates the effect of graphene oxide (GO) on the chloride binding capacity of cement paste and stability of Friedel's salt under different pH conditions. Experiments of X-ray diffraction (XRD), Thermogravimetric analyzer (TGA), Scanning electron microscope (SEM) and Energy dispersive spectroscopy (EDS) were performed to analyze the phase assemblage, micro morphology, element ratio and the enhanced mechanisms. Results showed that the 0.2 wt% GO addition …


Anti-Washout Concrete: An Overview, Hao Lu, Xiao Sun, Hongyan Ma Aug 2022

Anti-Washout Concrete: An Overview, Hao Lu, Xiao Sun, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Anti-washout concrete (AWC) is a special cement-based material that can be directly employed in underwater environments without dispersion. It was developed around 50 years ago, and more than 150 journal articles and technical reports have been published. This paper provides a holistic review about the basic fresh-state and hardened-state properties of the AWC, such as water (washout) resistance, consistency, bleeding and segregation resistance, mechanical properties, and durability, as well as relevant testing methods. The discrepancies between AWC's characteristics and those of conventional concrete are clearly presented. The mixture compositions, supplementary cementitious materials (SCMs), and other conditions that affect AWC's performance …


The Use Of Gpr To Investigate The Effect Of Steel Fiber Distribution On The Mechanical Behavior Of Frc, Paola Machado Barreto Manhães, José Tavares Araruna Júnior, Genda Chen, Neil Lennart Anderson, Erik Valloti Pereira, Flávio De Andrade Silva Aug 2022

The Use Of Gpr To Investigate The Effect Of Steel Fiber Distribution On The Mechanical Behavior Of Frc, Paola Machado Barreto Manhães, José Tavares Araruna Júnior, Genda Chen, Neil Lennart Anderson, Erik Valloti Pereira, Flávio De Andrade Silva

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The present work focuses on the steel fiber distribution in self-consolidating concrete short beams. The objective is to assess the feasibility of the ground penetrating radar (GPR) in evaluating the homogeneity of fibers within concrete materials, for use in testing laboratories to study the modes of placing and compaction employed for preparing specimens during quality control or material development. Self-consolidating concrete beams were cast, tested, and evaluated. A GPR survey employing a concrete scanning system with a shielded 1.2 GHz center frequency was performed on self-consolidating casted short beams just before a monotonic four-point bending test was carried out. After …