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Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Evaluating Structural Build-Up At Rest Of Mortar And Concrete, Sofiane Amziane, Kamal Khayat, Mohammed Sonebi, Arnaud Perrot Oct 2023

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Evaluating Structural Build-Up At Rest Of Mortar And Concrete, Sofiane Amziane, Kamal Khayat, Mohammed Sonebi, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Paper Presents the Results of a Round-Robin Testing Program Undertaken by RILEM TC-266-Measuring Rheological Properties of Cement-Based Materials in May 2018 at the Université D'Artois in Bethune, France. Seven Types of Rheometers Were Compared; They Consisted of Four ICAR Rheometers, Viskomat XL Rheometer, EBT-V Rheometer, Sliding Pipe Rheometer (SLIPER), RheoCAD Rheometer, and 4SCC Rheometer, as Well as the Plate Test. This Paper Discusses the Results of the Evolution of the Static Yield Stress at Rest of Three Mortar and Five Concrete Mixtures that Were Determined using Two ICAR Rheometers, Viskomat XL, and EBT-V Rheometers, as Well as the Plate …


Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete, Mohamed Leithy, Eslam Gomaa, Ahmed A. Gheni, Mohamed Elgawady Aug 2023

Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete, Mohamed Leithy, Eslam Gomaa, Ahmed A. Gheni, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, incorporating the waste latex paint (WLP) into the conventional concrete as a partial replacement of sand to improve its durability was investigated. The fresh and hardened characterizations, in addition to the durability of concrete, were examined. The slump test was used to evaluate the fresh properties, while the hardened properties were evaluated through the volume of voids and absorption rate, in addition to the compressive, splitting tensile, and flexural strengths tests. The durability performance was evaluated by the surface resistivity, bulk electrical resistivity, as well as freeze and thaw resistance tests. The results showed a reduction in …


Nonlinear Impact-Echo Test For Quantitative Evaluation Of Asr Damage In Concrete, Clayton Malone, Hongbin Sun, Jinying Zhu Jun 2023

Nonlinear Impact-Echo Test For Quantitative Evaluation Of Asr Damage In Concrete, Clayton Malone, Hongbin Sun, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

Nonlinear acoustic methods demonstrate high sensitivity for concrete damage evaluation. Among these methods, nonlinear resonance acoustic methods have been widely used in laboratory tests on small scale test samples. In this study, a nonlinear impact-echo (IE) method was proposed for concrete damage evaluation, in which the IE frequency shift was measured at different impact force levels. The nonlinear IE test is similar to the nonlinear impact resonance acoustic spectroscopy (NIRAS) test in the experimental setup and analysis method. How- ever, the nonlinear IE test excites a local thickness resonance mode of a member instead of the global resonance vibration. Therefore, …


Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Rheometers, Mixtures And Procedures, Dimitri Feys, Mohammed Sonebi, Sofiane Amziane, Chafika Djelal, Khadija El-Cheikh, Shirin Fataei, Markus Greim, Irina Ivanova, Helena Keller, Kamal Khayat, Laurent Libessart, Viktor Mechtcherine, Ivan Navarrete, Arnaud Perrot May 2023

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Rheometers, Mixtures And Procedures, Dimitri Feys, Mohammed Sonebi, Sofiane Amziane, Chafika Djelal, Khadija El-Cheikh, Shirin Fataei, Markus Greim, Irina Ivanova, Helena Keller, Kamal Khayat, Laurent Libessart, Viktor Mechtcherine, Ivan Navarrete, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent developments in understanding the rheology of mortar and concrete as well as applying this understanding in the practice of construction necessitate an accurate assessment of materials' rheological properties. It is well known that different rheometers for mortar and concrete deliver different results, as this was shown over 15 years ago in two measuring campaigns comparing concrete rheometers. Considering newly developed rheometers, including those to evaluate interface rheology and structural build-up at rest, as well as additional measurement procedures and data interpretation techniques, a new comparison campaign was carried out in 2018 at the Université d'Artois, in Bethune, France. This …


Editorial: Ultra-High Performance Concrete: Computation And Simulation Methods, Xinpeng Wang, Yitong Ma, Dongshuai Hou, Hongyan Ma, Yue Zhang Jan 2023

Editorial: Ultra-High Performance Concrete: Computation And Simulation Methods, Xinpeng Wang, Yitong Ma, Dongshuai Hou, Hongyan Ma, Yue Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Review Of Fly-Ash As A Supplementary Cementitious Material, Nikki Shaji, Niall Holmes Dr., Mark Tyrer Aug 2022

Review Of Fly-Ash As A Supplementary Cementitious Material, Nikki Shaji, Niall Holmes Dr., Mark Tyrer

Conference papers

This paper presents a review of fly-ash as a Supplementary Cementitious Material (SCM) in concrete in terms of its effects on hydration and durability. The climate change agenda has focused the cement and concrete industry on using low embodied CO2 materials and much effort has been made on incorporating industrial by-products into cement as SCMs. With worldwide cement production (circa 4 billion tonnes) currently accounting for approximately 8% of global CO2 emissions and 7% of industry energy use, the use of suitable SCMs to partially replace cement in concrete is extremely important. However, while coal-fired power stations are in the …


Applications Of Stretching Technique And Time Window Effects On Ultrasonic Velocity Monitoring In Concrete, Bibo Zhong, Jinying Zhu Jul 2022

Applications Of Stretching Technique And Time Window Effects On Ultrasonic Velocity Monitoring In Concrete, Bibo Zhong, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

Coda wave interferometry (CWI) has been used to measure the relative wave-velocity change (dV/V) caused by small changes in materials. This study uses the stretching processing technique which has been used for CWI analysis to investigate velocity changes of direct longitudinal (P) wave, direct shear (S) wave, and coda wave in concrete by choosing different time windows of ultrasonic signals. It is found that the obtained wave-velocity change depends on the time window position, because the relative contribution of P wave and S wave is different in each signal window. This paper presents three experimental scenarios of velocity …


Assessing The Effectiveness Of Problem-Based Learning Across Two Concrete Construction Courses, Anthony Torres, Jiong Hu, Vedaraman Sriraman, Araceli Martínez-Ortiz, Jorge Membrillo-Hernández May 2022

Assessing The Effectiveness Of Problem-Based Learning Across Two Concrete Construction Courses, Anthony Torres, Jiong Hu, Vedaraman Sriraman, Araceli Martínez-Ortiz, Jorge Membrillo-Hernández

Department of Civil and Environmental Engineering: Faculty Publications

The goal of this study is to assess the effectiveness of a Problem-Based Learning (PBL) pedagogy that was implemented in two different concrete construction courses. Both courses are a part of an industry focused four-year undergraduate concrete degree program. One of the classes focused on concrete problems, diagnosis, and repair of existing concrete, while the other class focused on handling and management methods of various concrete mixtures. In both courses, a PBL pedagogy was implemented such that students were self-learning and discovering the knowledge through an action-research case study. The action-research case study was specific to the course outcomes relevant …


Pumping Of Concrete: Understanding A Common Placement Method With Lots Of Challenges, Dimitri Feys, Geert De Schutter, Shirin Fataei, Nicos S. Martys, Viktor Mechtcherine Apr 2022

Pumping Of Concrete: Understanding A Common Placement Method With Lots Of Challenges, Dimitri Feys, Geert De Schutter, Shirin Fataei, Nicos S. Martys, Viktor Mechtcherine

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Several million cubic meters of concrete are pumped daily, as this technique permits fast concrete placement. Fundamental research has been performed and practical guidelines have been developed to increase the knowledge of concrete behavior in pipes. However, the pumping process and concrete behavior are not fully understood. This paper gives an overview of the current knowledge of concrete pumping. At first, the known physics governing the flow of concrete in pipes are introduced. A series of experimental techniques characterizing concrete flow behavior near a smooth wall to predict pressure-flow rate relationships are discussed, followed by recent developments in the use …


Applications Of Stretching Technique And Time Window Effects On Ultrasonic Velocity Monitoring In Concrete, Bibo Zhong, Jinying Zhu Jan 2022

Applications Of Stretching Technique And Time Window Effects On Ultrasonic Velocity Monitoring In Concrete, Bibo Zhong, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

Coda wave interferometry (CWI) has been used to measure the relative wave-velocity change (dV/V) caused by small changes in materials. This study uses the stretching processing technique which has been used for CWI analysis to investigate velocity changes of direct longitudinal (P) wave, direct shear (S) wave, and coda wave in concrete by choosing different time windows of ultrasonic signals. It is found that the obtained wave-velocity change depends on the time window position, because the relative contribution of P wave and S wave is different in each signal window. This paper presents three experimental scenarios of velocity …


Field Implementation And Monitoring Of An Ultra-High Performance Concrete Bridge Deck Overlay, Craig Newtson, Brad Weldon, William Toledo, Andres Alvarez, Mark Manning Dec 2021

Field Implementation And Monitoring Of An Ultra-High Performance Concrete Bridge Deck Overlay, Craig Newtson, Brad Weldon, William Toledo, Andres Alvarez, Mark Manning

Publications

This project focused on field implementation of an ultra-high performance concrete (UHPC) overlay during rehabilitation of an existing concrete bridge (No. 7032) deck in Socorro, New Mexico, USA. Bridge 7032 is a two-lane bridge that is approximately 300 ft. (91.4 m) long and 54 ft. (16.5 m) in width. Rehabilitation of bridge 7032 included removal of deteriorated concrete from the existing deck, installation of a high-performance deck (HPD) leveling course, and installation of a 1 in. (25 mm) UHPC overlay. An UHPC mixture with a 19.5 ksi (134 MPa) compressive strength developed in previous research was selected for this project. …


Measuring Foundation Course Modulus Using Falling Weight Deflectometer, Light Weight Deflectometer, And Dynamic Cone Penetration, Bruce Barrett, Kellie Troxel, Brady Dresselhaus, David Hansen Dec 2021

Measuring Foundation Course Modulus Using Falling Weight Deflectometer, Light Weight Deflectometer, And Dynamic Cone Penetration, Bruce Barrett, Kellie Troxel, Brady Dresselhaus, David Hansen

Nebraska Department of Transportation: Research Reports

Phase I results showed that FWD, LWD, and DCP provided valid results and trended with each other at the stations all three tests were run. This gives confidence that any test method is reliable when used on an exposed bituminous foundation course.

The results of Phase I and Phase II indicate that using FWD testing after concrete is built does not provide an accurate modulus of the foundation course. As demonstrated through the statistical analysis, foundation course moduli cannot be reliably calculated by using FWD on top of doweled concrete pavements and back-calculated using Darwin software or ME Design. Additionally, …


Application Of Biochar As Beneficial Additive In Concrete, Temirlan Barissov Dec 2021

Application Of Biochar As Beneficial Additive In Concrete, Temirlan Barissov

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

Biochar is a high-carbon solid material produced via thermal decomposition of organic biomass in a low-oxygen environment. Characterized with high water retention properties and high alkalinity, biochar is generally used for soil amendment and fertilization purposes. This study is intended to explore the feasibility of using biochar as a beneficial additive of the most used manmade material, concrete. Literature review revealed several studies where biochar was successfully implemented as an additive in concrete. The beneficial influence of biochar on the mechanical characteristics of concrete is based on nucleation and densification effects. However, the internal microstructure, porosity and chemical composition of …


Durability Of Concrete Produced With Alternative Supplementary Cementitious Material, Craig Newtson, Brad Weldon, Judit Garcia, Seyedsaleh Mousavinezhad, William Toledo Nov 2021

Durability Of Concrete Produced With Alternative Supplementary Cementitious Material, Craig Newtson, Brad Weldon, Judit Garcia, Seyedsaleh Mousavinezhad, William Toledo

Publications

Historically, Class F fly ash has been chosen as a supplementary cementitious material (SCM) in concrete for its ability to mitigate alkali-silica reaction (ASR). However, future availability of fly ash is uncertain because the energy industry has been investing in renewable energy production and removing coal burning generating stations from operation. Consequently, there is a growing need to find new, cost effective and environmentally friendly alternatives to fly ash. This study investigated a locally available natural pozzolan mined from a pumicite deposit near Espanola, NM for its ability to mediate ASR. Concrete and mortar mixtures included SCM contents ranging from …


Assessment Of Deteriorated Structural Concrete To Provide Durable Repairs, Theodore Hopwood, Christopher Goff, Sudhir Palle Nov 2021

Assessment Of Deteriorated Structural Concrete To Provide Durable Repairs, Theodore Hopwood, Christopher Goff, Sudhir Palle

Kentucky Transportation Center Research Report

Most of the structural elements on Kentucky bridges are made of reinforced concrete. Many of these elements deteriorate as a result of corrosion of the reinforcing steel caused by carbonation and — primarily — applications of chlorides by the Kentucky Transportation Cabinet (KYTC). Corrosion of reinforcing steel is reviewed along with assessment procedures that leverage nondestructive evaluation (NDE) methods and related laboratory and field tests. Several maintenance procedures are discussed, including the application of sealers and coatings, patch and major concrete repairs, and electrochemical methods. Incorporating NDE and test results into maintenance procedure selection is discussed. Recommendations are provided on …


Development Of Novel Ultra-High Performance Engineered Cementitious Composites (Uhp-Ecc) For Durable And Resilient Transportation Infrastructure, Gabriel A. Arce, Marwa Hassan, Daniel E. Game Sep 2021

Development Of Novel Ultra-High Performance Engineered Cementitious Composites (Uhp-Ecc) For Durable And Resilient Transportation Infrastructure, Gabriel A. Arce, Marwa Hassan, Daniel E. Game

Publications

The objective of this study was to develop novel UHP-ECC materials utilizing readily available ingredients in Region 6 for the construction and repair of transportation infrastructure. Phase one of this study focused on the development of ultra-high strength cementitious matrices by evaluating the effects of ingredient selection and mixture proportioning on the materials’ compressive strength. Variables evaluated included the mass ratios of silica fume to fly ash (SF/FA), supplementary cementitious materials to cement (SCMs/C), and ordinary sand to microsilica sand (OS/MS). Phase two of the study focused on the development of UHP-ECC materials. To this end, based on the knowledge …


Evaluation Of Alternative Sources Of Supplementary Cementitious Materials (Scms) For Concrete Materials In Transportation Infrastructure, Gabriel A. Arce, Miladin Radovic, Zahid Hossain, Marwa Hassan, Sujata Subedi Aug 2021

Evaluation Of Alternative Sources Of Supplementary Cementitious Materials (Scms) For Concrete Materials In Transportation Infrastructure, Gabriel A. Arce, Miladin Radovic, Zahid Hossain, Marwa Hassan, Sujata Subedi

Publications

Fly ash is the most utilized supplementary cementitious material (SCM) in the US. Nonetheless, rapid decline in coal-fired power generation threatens its supply. The objective of this study was to evaluate alternative SCMs for concrete transportation infrastructure in Region 6. SCMs investigated included reclaimed fly ash (RFA), reclaimed ground bottom ash (GBA), metakaolin (MK), and conventional Class F fly ash (FA) as a reference. SCMs were characterized and the fresh and hardened properties of concrete incorporating different dosages (i.e., 10, 20, and 30% cement replacement by mass) of the individual SCMs (i.e., binary systems) and blended SCM systems of RFA-MK …


Multi-Sensor Data Collection And Fusion Using Autoencoders In Condition Evaluation Of Concrete Bridge Decks, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Kwanghee Won, Brian A. Mazzeo, W Spencer Guthrie Jun 2021

Multi-Sensor Data Collection And Fusion Using Autoencoders In Condition Evaluation Of Concrete Bridge Decks, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Kwanghee Won, Brian A. Mazzeo, W Spencer Guthrie

Department of Civil and Environmental Engineering: Faculty Publications

This paper presents a multi-sensor data collection and data fusion procedure for nondestructive evaluation/testing (NDE/NDT) of a concrete bridge deck. Three NDE technologies, vertical electrical impedance (VEI), ground-penetrating radar (GPR), and high-definition imaging (HDI) for surface crack detection, were deployed on the bridge deck. A neural network autoencoder was trained to quantify the relationship between VEI and GPR results using the data collected at common positions. This relationship was then used for fusion of VEI and GPR data to increase the reliability and spatial resolution of the NDE measurements and to generate a data-fused condition map that showed novel characteristics. …


Reliability Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon May 2021

Reliability Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The reliability of reinforced concrete bridge columns strengthened with externally bonded, steel-fiber reinforced polymer fabric subjected to blast loads was investigated. Columns were modeled with a nonlinear finite element approach that considers material damage, fracture, and separation. Different concrete strengths, longitudinal reinforcement ratios, and gravity and blast load levels were considered, while uncertainties in material strength and stiffness parameters, as well as load characteristics, were incorporated in the probabilistic analysis. It was found that the use of SFRP can allow significant increases in blast load while maintaining the same level of column reliability.


Application Of Ultrasonic Measurements For The Evaluation Of Steel Fiber Reinforced Concrete, Belayhun Gebretsadik, Kazem Jdidirendi, Visar Farhangi, Moses Karakouzian Jan 2021

Application Of Ultrasonic Measurements For The Evaluation Of Steel Fiber Reinforced Concrete, Belayhun Gebretsadik, Kazem Jdidirendi, Visar Farhangi, Moses Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

This study investigates the feasibility of the application of ultrasonic measurement to characterize Steel-Fiber-Reinforced Concrete (SFRC). Specifically, the effects of steel fiber content, age, moisture content, and fiber orientation on Ultrasonic-Pulse-Velocity (UPV) were investigated. In this regard, beam and cylindrical samples were fabricated with different steel fiber contents. The result indicated that for beam specimens the UPV increases with the addition of fiber up to 2% and decreases for higher fiber percentages. Additionally, the fiber orientation within the beam specimens influences the UPV measurements. For cylindrical samples, the rate of UPV decreased with the addition of steel fiber reinforcement. In …


Evaluation Of Bagasse Ash As Cement And Sand Replacement For The Production Of Engineered Cementitious Composites (Ecc), Gabriel Arce, Marwa Hassan, Sujata Subedi, Ana Rivas, Samantha Hidalgo, Hugo Eguez Nov 2020

Evaluation Of Bagasse Ash As Cement And Sand Replacement For The Production Of Engineered Cementitious Composites (Ecc), Gabriel Arce, Marwa Hassan, Sujata Subedi, Ana Rivas, Samantha Hidalgo, Hugo Eguez

Publications

The objective of this study was to develop novel Engineered Cementitious Composites (ECC) materials implementing sugarcane bagasse ash (SCBA). To this end, the effects on the mechanical and physical properties of ECC materials of: (1) Louisiana raw SCBA (RBA) as a partial and complete replacement of sand (i.e., class S mixtures); (2) Louisiana post-processed SCBA (PBA) as a partial replacement of cement (i.e., class C mixtures); and (3) Ecuador raw SCBA (EBA) as a partial and complete replacement of sand (i.e., class S-E mixtures) were studied. Sand replacement levels with RBA and EBA evaluated were 25, 50, 75, and 100% …


Colloidal Silica: Cement Enhancing Admixture Product Evaluation, Lieska Halsey, David Hansen Sep 2020

Colloidal Silica: Cement Enhancing Admixture Product Evaluation, Lieska Halsey, David Hansen

Nebraska Department of Transportation: Research Reports

As Class F- fly ash (F-ash) becomes scarce, PCC engineers will look to other supplemental cementitious materials (SCM) to replace F-ash and its ASR mitigating properties. Colloidal silica (CS), or nano-silica, has been shown to mitigate ASR at certain replacement levels; however, CS cannot be a full replacement of F-ash. Engineers at the Nebraska Department of Transportation (NDOT) learned of CS from a presentation given by Intelligent Concrete, Inc. at the 2019 Nebraska Concrete Professionals Association Conference and decided to investigate the potential use of CS in NDOT concrete mix designs.


Seismic Design Coefficients For Speedcore Or Composite Plate Shear Walls - Concrete Filled (C-Psw/Cf), Shubham Agrawal, Morgan Broberg, Amit H. Varma Aug 2020

Seismic Design Coefficients For Speedcore Or Composite Plate Shear Walls - Concrete Filled (C-Psw/Cf), Shubham Agrawal, Morgan Broberg, Amit H. Varma

Bowen Laboratory Research Reports

This report summarizes the results from FEMA P695 analytical studies conducted to verify the seismic design factors for composite plate shear walls – concrete filled (C-PSW/CF), also referred to as Speedcore. ASCE 7-16 provides the seismic design factors, which include the seismic response modification factor, R, deflection amplification factor, Cd, and overstrength factor, Ωo, for various approved seismic systems. C-PSW/CFs are assigned a response modification factor of 6.5, a deflection amplification factor of 5.5, and an overstrength factor of 2.5 for C-PSW/CFs. These seismic design factors were selected based on the seismic performance of similar structural …


Quantitative Assessment Of Alkali-Silica Reaction In Small And Large-Scale Concrete Specimens Utilizing Nonlinear Acoustic Techniques, Clayton Malone Aug 2020

Quantitative Assessment Of Alkali-Silica Reaction In Small And Large-Scale Concrete Specimens Utilizing Nonlinear Acoustic Techniques, Clayton Malone

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

Nonlinear resonance techniques have been shown to be sensitive to microcracking in materials, including alkali-silica reaction (ASR) damage in concrete. However, application of nonlinear resonance tests have been limited due to the difficulty of application to large-scale field structures and the inability to quantitatively relate material nonlinearity with damage development. In this study, the development of ASR in concrete prisms and large concrete beam specimens of varying aggregate types and specimen sizes was monitored using linear and nonlinear resonance techniques.

For the concrete prisms, although the linear resonance frequency test could detect initiation and development of ASR damage in specimens …


Fly Ash Based Geopolymer For High Temperature And High Compressive Strength Applications In Aggressive Environment, Aaryan Manoj Nair, Akm S. Rahman May 2020

Fly Ash Based Geopolymer For High Temperature And High Compressive Strength Applications In Aggressive Environment, Aaryan Manoj Nair, Akm S. Rahman

Publications and Research

Geopolymers are the results of geosynthetic reactions between aluminosilicates and strong bases. This results in chemical bonds between aluminum (Al), Silicon (Si)and oxygen (O) composing polymer rings in tetrahedral coordination. These bonds give them widespread useful applications such as high heat bearing ceramics, and base construction material whilst being far more environmentally conscious. The purpose of the experiment is to examine the effect of Silicon Carbide whisker and inorganic glass particles on thermal and mechanical properties of Geopolymers. This study will help understand the effect of various compositions and concentrations of SiO2 in mechanical strength. In this experiment, the …


Quantitative Resistance Assessment Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon Apr 2020

Quantitative Resistance Assessment Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The blast resistance of a typical reinforced concrete bridge pier column design was modeled with a nonlinear finite element approach that considers material damage, fracture, and separation. While varying concrete strength, amount of longitudinal reinforcing steel, and gravity load, the effect of applying an externally bonded steel fiber reinforced polymer (SFRP) wrapping was assessed. The presented approach uniquely quantifies column blast resistance in terms of charge weight. It was found that blast capacity was roughly linearly related to concrete strength and steel reinforcement ratio, the former of which is most influential. It was further found that a single layer of …


Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu Apr 2020

Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu

Nebraska Department of Transportation: Research Reports

Due to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is prone to premature cracking. Internal curing has been found to greatly reduce the chance of premature cracking as well as concrete deterioration. This research project was intended to develop internally cured bridge deck concrete based on a local mix design in Nebraska. Four different lightweight fine aggregate (LWFA) as internal curing agents were evaluated, and their effects on fresh, mechanical, durability, and shrinkage properties of concrete were studied. To identify the most effective LWFA dosage for shrinkage reduction, different replacement rates of sand …


Estimation Of Lubrication Layer Thickness And Composition Through Reverse Engineering Of Interface Rheometry Tests, Alexis Salinas, Dimitri Feys Apr 2020

Estimation Of Lubrication Layer Thickness And Composition Through Reverse Engineering Of Interface Rheometry Tests, Alexis Salinas, Dimitri Feys

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

During concrete pumping, a lubrication layer is formed near the pipe wall. Extensive research has been performed on measuring and modeling the properties of this layer and using these values to predict pumping pressures. However, there are numerous discussions in the literature about the composition and thickness of this layer: can it be considered mortar, a micromortar, or is it cement paste? In this paper, possible solutions for the thickness and composition of the lubrication layer are derived from interface rheometry tests. It is assumed that the lubrication layer is composed of one or more concentric layers of paste or …


The Viability And Simplicity Of 3d-Printed Construction: A Military Case Study, Jeneé A. Jagoda, Brandy Diggs-Mcgee, Megan Kreiger, Steven J. Schuldt Apr 2020

The Viability And Simplicity Of 3d-Printed Construction: A Military Case Study, Jeneé A. Jagoda, Brandy Diggs-Mcgee, Megan Kreiger, Steven J. Schuldt

Faculty Publications

In November 2019, U.S. Marines, Air Force, and Army Corps of Engineers personnel demonstrated the viability and simplicity of three-dimensionally (3D)-printed construction in a controlled environment at the U.S. Army Engineer Research and Development Center—Construction Engineering Research Laboratory in Champaign, Illinois. The tri-service exercise spanned three days and culminated in the construction of three 1 m × 1 m × 1 m (3 ft × 3 ft × 3 ft) concrete dragon’s teeth (square pyramid military fortifications used to defend against tanks and armored vehicles) and several custom-designed objects. The structural components were printed using a custom-built, gantry-style printer called …


Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen Jan 2020

Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen

Nebraska Department of Transportation: Research Reports

Tie bars are epoxy coated steel bars that connect the longitudinal joints in concrete pavement. Tie bars prevent faulting and joint separation between lanes Tie bars can be placed into the plastic concrete or inserted after curing by drilling and anchoring with epoxy or non-shrink grout. The specification for the tie bars requires the use of a No. 5 bar, 18 inches long and shall meet ASTM A775 / A775M [1], Section 1020.The Nebraska Department of Transportation “Standard Specifications for Highway Construction,” (Section 603.03) requires contractors to mechanically insert tie bars into the face of pavements during construction. Tie bars …