Structural Engineering Commons^™

Influence Of Phosphorus Sources On The Compressive Strength And Microstructure Of Ferronickel Slag-Based Magnesium Phosphate Cement, Cuirong Yan, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Luxing Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Electric furnace ferronickel slag (EFS) is a typical magnesium-rich industrial by-product discharged from the manufacture of nickel and iron-nickel alloys. The approach to use it as the raw material for the preparation of magnesium phosphate cement (MPC) has potential and proves effec-tive. In this study, three different phosphorus sources (PS) including phosphoric acid (H₃PO₄, PA), sodium dihydrogen phosphate (NaH₂ PO₄, SDP) and potassium dihydrogen phosphate (KH₂ PO₄, PDP) were used to react with EFS to prepare the EFS-based MPC (EMPC), and the effects of raw material mass ratio (EFS/PA, EFS/SDP, …

Effects Of Long Duration Earthquakes On The Interaction Of Inertial And Liquefaction-Induced Kinematic Demands On Pile-Supported Wharves, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Nason Mccullough, Scott Schlechter

Civil and Environmental Engineering Faculty Publications and Presentations

Nonlinear dynamic analyses were performed to evaluate the effects of ground motion duration on the dynamic response of a pile-supported wharf subjected to liquefaction-induced lateral ground deformations. The numerical model was first calibrated using recorded data from a well-instrumented centrifuge test, after which incremental dynamic analyses were conducted using a suite of spectrally matched motions with different durations. The nonlinear dynamic analyses were performed to evaluated three loading scenarios: combined effects of inertial loads from the wharf deck and kinematic loads from ground deformations, deck inertial loads only in the absence of liquefaction (with minimal kinematic loads), and kinematic loads …

Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi

Tanzania Journal of Engineering and Technology (TJET)

The Resilient Modulus (Mr) is a fundamental material property input in modern Mechanistic-Empirical (M-E) pavements structural design. Empirical pavement design methods have been in use over a long period during which large databases of four- days-soaked California Bearing Ratio (CBR) values at or near the Maximum Dry Density have been generated in the strength assessments for Unbound Granular Materials (UGMs). In the adoption of the M-E design approach researchers have so far attempted with various degrees of success to develop models to derive resilient modulus from the conventional CBR-based databases. This study provides an extensive laboratory experimental study to investigate …

Setting Times Of Early-Age Mortars Determined From Evolution Curves Of Poisson’S Ratio, Bate Bate, Xiao Chen, Chao Chen, Hongyan Ma, Jianfeng Zhu, Junnan Cao, Jiakai Chen, Kamal Khayat, Shuai Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Setting times, as the early-age properties of cement-based materials, are important properties to ensure the quality and long-term performance of engineering structures. To determine the initial and final setting times of cementitious materials, the compressive wave velocity and shear wave velocity of six early-age mortar samples were monitored. Their time evolution curves of Young's modulus, shear modulus, bulk modulus, and Poisson's ratio were then calculated and analyzed. The signature times of the derivatives of the Poisson's ratio evolution curves correlate well with the initial and final setting times, and the remarkably high coefficient of determination values relative to the data …

Blast Analysis Of Steel-Plate Composite Slabs: Sdof And Fem Analyses, Joshua R. Harmon, Amit H. Varma

Bowen Laboratory Research Reports

Steel-plate composite (SC) members have emerged as competitive construction methods for tall buildings and nuclear power plants. Detailed design guidance has been created for these functions and design of these members is now covered in AISC 341-16 and ASIC N690-18. However, SC members are emerging for use in protective structures to withstand blast and impact loads. Although experimental tests of SC members for blast resistant design have been conducted, design of SC members for blast loads has not been addressed in existing design references for blast loadings (UFC 3-340-02). This report details a general design philosophy for blast loaded SC …

Flexural Strengthening Of Rc Slabs Using Near Surface Mounted Gfrp Bars, Sama Taha

Theses and Dissertations

Glass Fiber reinforced polymers (GFRPs) have been recently successfully used to increase reinforced concrete elements' strength. In general, FRPs have many advantages such as resistance to corrosion, and high strength-to-weight ratio. On the other hand, debonding from concrete may constitute a limitation to using GFRP bars; hence the increase in strength of RC elements strengthened using GFRP bars may be limited by this premature debonding failure mechanism.

This study aims to investigate the strengthening effect of GFRP bars on the capacity of RC slabs when subject to flexure loading. The work studies the use of different bonding lengths, diameters and …

Strengthening Of Long Rc Columns Using Near Surface Mounted Gfrp Bars, Ahmed Romaih

Theses and Dissertations

Many of the existing reinforced concrete (RC) columns are deficient because of numerous reasons such as increase in service loads, deterioration due to environmental attacks, errors in the design and/or construction phase or in the worst case, accidents. These elements require strengthening or repair. Different methods have been developed over the years for solving different rehabilitation problems. Recently, advanced composites used for external bonding in the form of fabrics or laminates have become an accepted method. The use of Fibre-Reinforced Polymers (FRPs) in this process is a promising technology, especially that these materials are corrosion-free. One of the new techniques …

Steel Diaphragm Innovation Initiative, Year 5, Final Report *Addendum*, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

Preface

The Steel Diaphragm Innovation Initiative (SDII) is a multi-year industry-academic-government partnership to advance the seismic performance of steel floor and roof diaphragms utilized in steel buildings. This addendum to the final report covers work conducted on Task 5.6 which was completed during a no-cost extension conducted in 2021. Please refer to AISI RP21-04, the Steel Diaphragm Innovation Initiative, Year 5, Final Report for all other details.

Inspire Newsletter Spring 2022, Missouri University Of Science And Technology. Inspire - University Transportation Center

INSPIRE Newsletters

No abstract provided.

Inspire Newsletter Fall 2022, Missouri University Of Science And Technology. Inspire - University Transportation Center

INSPIRE Newsletters

No abstract provided.

Quantitative Bridge Inspection Ratings Using Autonomous Robotic Systems, Anil K. Agrawal

Project IM-2

Impact sounding has been recognized as an effective technique to detect delamination in concrete structures, such as concrete decks. An enormous amount of sounding data can be generated/collected by the autonomous inspection systems equipped with impactors and microphones. However, the main challenge in the practical application of this technology is the development of advanced data analysis approaches for identifying defects from impact sounding data. In this study, the empirical mode decomposition (EMD) analysis and power-spectral density (PSD) analysis are combined to extract useful features of sounding data generated by the impact hammer. It has been found that the EMD method …

Post-Seismic Response And Repair Of Earthquake-Damaged Reinforced Concrete Bridges, Giacomo Fraioli

Doctoral Dissertations

“In bridge structures, column members are typically designed to be the primary source of energy dissipation during an earthquake. Therefore, reinforced concrete (RC) bridges that are damaged in an earthquake tend to have damage to the column members. While many studies have been conducted on seismic strengthening of RC bridge columns, most are focused on retrofit instead of repair. In addition, the limited research on seismic repair of RC bridges has focused on evaluating the response of individual columns (member level), not the bridge structure (system level), due to limitations in modeling and especially testing of full bridge structures. Local …

Numerical Assessment Of Post-Tensioned Slabs Due To Seismic Column Collapse, Mariam Ehab, Aya Elhozayen

Civil Engineering

In our recent catastrophes, Progressive collapse become an essential behavior that should be researched widely and to be considered by engineers through the design process. The main vertical loss can be caused by different reasons, either blast due to terrorist attack, failure of columns due to extreme earthquake application, or finally, losing a structural element due to high impact resulted from a vehicle or any other moving object. Losing main vertical element due to extreme earthquake excitation is an important and repeated occurrence, However, it didn’t take much attention in progressive collapse recent studies. Unified Facilities Criteria (UFC) and General …

An Examination Of Effective Length In Moment Frames, Connor Stephen Schott

Honors Theses and Capstones

The honors thesis project I have been working on is called An Examination of Effective Length in Moment Frame. When loaded axially in compression columns experience a failure mode in compression that axially loaded members don’t experience in tension. This failure mode, elastic column buckling, doesn’t involve yielding or rupture; the column changes shape and deforms to the side. In order to come up with a solution to this failure mode, Leonhard Euler developed the critical buckling load equation. However, this equation uses an effective length of columns, which is the distance between two points of zero moment, or …

Analysis Of Shear Failure In Ultra-High Performance Concrete Beams, Kevin Conway

Electronic Theses and Dissertations, 2020-2023

Ultra-high performance concrete (UHPC) is an emerging cementitious material type currently undergoing research in different structural applications. This material is characterized by a compressive strength of 150 MPa (22 ksi), according to the Association Francaise de Genie Civil and the Federal Highway Administration, high tension strength, and high durability. Additionally, UHPC consists of secondary reinforcement in the form of steel or polymeric fibers, which enable UHPC to exhibit tension hardening behavior and tension ductility previously ignored in conventional concrete mixes. Previous research has focused on applications in the transportation and bridge design industries; however, applications in buildings and other heavy …

Repairable Precast Bridge Bents For Seismic Events, Kallan Hart

Electronic Theses and Dissertations

Concrete bridge columns are designed to withstand earthquakes by undergoing large displacements. Current seismic bridge codes guarantee collapse prevention, but damage to concrete and longitudinal reinforcement often requires demolition of the structure. Repairable detailing and advanced bridge construction connections may be utilized in concrete bridge columns to allow for quick construction as well as replacement of damaged reinforcement after an earthquake. This detailing may be an attractive alternative to bridge owners to reduce construction and replacement costs as well as ensure the functionality of critical routes after an earthquake. Three repairable precast bridge columns with exposed longitudinal reinforcement were tested …

Parametric Study On Environmental Friendly Blast Wall Systems, Mariam Ehab, Aya Elhozayen

Civil Engineering

Protecting people and structures against blast loading that can happen due to several reasons such as wars, terrorism or even accidental explosions, has become of great concern during the last decade. Blast walls is considered as one of the most effective ways to protect important structures against such hazards. However, limitation in technology of construction using high –technology blast wall systems are a huge obstacle specially in developed countries. Moreover, using high-technology materials in construction industry are very polluting process along with the high expenses during construction phase. As a result, designers tend to propose solutions with readily available materials …

North 14th Street Corridor Improvements Project, Ashley Nguyen, Samantha Corey, Maricela Paramo Reyes, Pooja Rajeev

Honors Program: Senior Projects (Public)

The following project report was a study of the North 14^th Street corridor ranging from Adams Street to Virginia Street conducted by University of Nebraska-Lincoln students for a senior design capstone project. Main focuses of the project were the intersection of Adams and 14^th Street and the 14^th Street bridges over Cornhusker Highway and Oak Creek. Study of this area included work in transportation, traffic, structural, geotechnical, water resources, and environmental engineering. However, this report done by students should not take the place of work done by licensed professional engineers.

This project was done in collaboration with …

Tension-Stiffening Effect Consideration For Modeling Deflection Of Cracked Reinforced Uhpc Beams, Le Teng, Rongling Zhang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Tension-stiffening effects can significantly influence the flexural performance of cracked reinforced concrete specimens. Such effect is amplified for fiber-reinforced concrete, given the fact that fibers can bridge the cracks. The objective of this study was to develop a model to predict the deflection of cracked reinforced ultra-high performance concrete (R-UHPC) beam elements. The modeling approach characterized the average bending moment of inertia by combining the existing model used for conventional reinforced concrete and the analytical model of stress distribution of UHPC along the cross-section. The finite element analysis (FEA) was employed to evaluate the flexural deflection based on the average …

Comparative Analysis Of Bridge Abutment Types, David Fell

Williams Honors College, Honors Research Projects

This project was developed to serve as a brief overview of design practices and considerations in the selection of highway bridge abutment types. This involved a review of literature in the form of reviewing national design guides and department of transportation (DOT) requirements from both US DOTs and international DOTs. The abutment types covered in this research included conventional reinforced concrete abutments with bearings, integral abutments, and semi-integral abutments. This research focused solely on highway bridge abutments, particularly on Ohio Department of Transportation design requirements due to their extensive use of semi-integral abutments. Superstructure elements and geometric requirements are primary …