Structural Engineering Commons^™

Ensemble-Learning Model Based Ultimate Moment Prediction Of Reinforced Concrete Members Strengthened By Uhpc, Woubishet Zewdu Taffese, Yanping Zhu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Data-driven model development brings new approaches to solve conventional civil engineering problems, which are usually considered and answered by experimental, analytical, and numerical methods. This study aims to develop an ensemble learning model (i.e., XGBoost: eXtreme Gradient Boosting) to predict ultimate moment of reinforced concrete (RC) members strengthened by a newly developed concrete technology – ultrahigh performance concrete (UHPC). The study considered two scenarios, incorporating eighteen and seventeen features, with one feature modification involving the transformation of width and height to the cross-sectional area of RC members. Incorporating three substrate damage levels, two substrate surface treatments preceding UHPC strengthening, and …

Experimental Study On Fiber Reinforced Concrete (Frc) Beams With Splices, Mohie Eldin Salah Shoukry, Ahmed Mokhtar Tarabia, Nabil Youssef Nabil

Journal of Engineering Research

This paper presents the results of an experimental study involving nine simply supported beams featuring lap-spliced bars within the constant moment zone. All beams shared identical reinforcement details, including three longitudinal reinforcement bars (12 mm diameter) and two top reinforcement bars (8 mm diameter) for shear stirrup hanging. The lap-spliced specimens were created with a splice length of thirty times the bar diameter (360 mm). The study focused on two key parameters: the fiber content of hooked-end steel fibers used in the concrete mix and the presence of stirrups in the lap-splice region. The hooked-end steel fiber used was with …

Effect Of Corrugation Properties On The Flexural Behavior Of Small-Scale Mono-Symmetric Steel Girders With Corrugated Webs, Ahmed Elgendy, Ahmed M. El Hadidy, Dr. Mahmoud Hassan Elboghdadi

Journal of Engineering Research

Steel girders with corrugated webs have been extensively researched and used in a variety of applications during the last few decades, including bridges and industrial buildings. Many studies explored the behavior of double symmetric girders with corrugated webs, but only a few articles used unequal flanges. Furthermore, the majority of research focuses on large-scale girders such as bridge girders, with just a few publications considering small-scale girders that may be employed in traditional construction applications. Additionally, performed investigations that consider the flexural behavior focused their studies on the effect of varying the dimensions of flanges without considering the effect of …

Finite Element Investigation For The Flexural Behavior Of Small-Scale Mono-Symmetric Steel Girders With Corrugated Webs, Ahmed H. Elgendy, Ahmed M. El Hadidy, Dr. Mahmoud Hassan Elboghdadi

Journal of Engineering Research

In the last decades, steel girders with corrugated webs have been widely investigated and implemented in many applications such as bridges and industrial facilities. Many researchers investigated the flexural behavior of traditional doubly symmetric girders with corrugated webs, but a very limited number of investigations considered the usage of unequal flanges. In addition, for most cases the performed investigations focus on the behavior of large-scale girders similar to bridge girders, while few papers considered small-scale girders that could be used in traditional structures. Thus, the objective of this paper is to investigate the lateral torsional buckling behavior of small-scale unsymmetric …

A 4-Node Shell Finite Element Based On Assumed Bending And Membrane Strains For Static Analysis Of Plates And Shells, Sifeddine Abderrahmani

Emirates Journal for Engineering Research

In this paper the development of a new rectangular flat shell element is proposed. This element is called SBRPK-SBRIE. This element is used in the numerical analysis of thin structures based on the strain approach with linear elastic behavior. Combining bending and membrane elements yields the proposed element.The strain-based rectangular finite element for the thin plate bending element denoted SBRPK, and the strain-based membrane element denoted SBRIE. Several numerical examples have been conducted to assess the accuracy and reliability of the developed element compared with the theoretical results and other finite elements. Obtained results show its good performance compared to …

Implementation Of Fluid Viscous Damper For 2023 Eeri Seismic Design Competition, Dalton J. Muck, Payton S. Mcgee, Payton R. Filippin, Tynan Castro

Architectural Engineering

The authors of this report were a part of the 2023 Earthquake Engineering Research Institute (EERI) student chapter for California Polytechnic State University, San Luis Obispo (Cal Poly). With thirteen other team members, they traveled to San Francisco, CA to compete in the Seismic Design Competition (SDC) hosted by EERI. The team was tasked with preparing a written proposal, design and computer analysis of the structural system, construction of two physical models, as well as creation of a poster and a presentation for a proposed mid-rise building located in the competition host city. The goal of the design of Cal …

Natural Gas Induced Vegetation Stress Identification And Discrimination From Hyperspectral Imaging For Pipeline Leakage Detection, Pengfei Ma, Ying Zhuo, Genda Chen, Joel G. Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Remote Sensing Detection of Natural Gas Leaks Remains Challenging When using Ground Vegetation Stress to Detect Underground Pipeline Leaks. Other Natural Stressors May Co-Present and Complicate Gas Leak Detection. This Study Explores the Feasibility of Identifying and Distinguishing Gas-Induced Stress from Other Natural Stresses by Analyzing the Hyperspectral Reflectance of Vegetation. the Effectiveness of This Discrimination is Assessed Across Three Distinct Spectral Ranges (VNIR, SWIR, and Full Spectra). Greenhouse Experiments Subjected Three Plant Species to Controlled Environmental Stressors, Including Gas Leakage, Salinity Impact, Heavy-Metal Contamination, and Drought Exposure. Spectral Curves Obtained from the Experiments Underwent Preprocessing Techniques Such as Standard …

Characterization Of Alkali-Silica Reaction (Asr) Products And C-S-H Using Swir Spectroscopy For Nondestructive Detection Of Asr, Pengfei Ma, Wenyu Liao, Ying Zhuo, Hongyan Ma, Yanping Zhu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study explores the feasibility of characterizing alkali-silica reaction (ASR) products and calcium silicate hydrates (C-S-H) from short-wave infrared (SWIR) spectroscopy. ASR products and C-S-H samples with different Ca/Si ratios were synthesized and analyzed through XRD, 29Si nuclei magnetic resonance (NMR) and SWIR spectroscopy. Fourier-transform infrared spectroscopy (FTIR) was collected to help interpret the results from the SWIR spectroscopy. The obtained spectroscopic features were applied to quantify the ASR product abundance denoted by the length expansion of mortar bars after an accelerated ASR test. The results show that the SWIR spectra of the synthetic ASR gels are similar regardless of …

Buckling Behavior Of Thin Wall Stiffened Cylindrical Shells Through Ml Techniques, Fnu Tabish, Muhammad Hamza Karim, Rajesh Godasu, Iraj H.P Mamaghani

SDSU Data Science Symposium

Stiffened cylindrical shell buckling strength mainly depends on the geometric and stiffness properties. A detailed parametric study was conducted to investigate the influence of these properties on the stiffened aluminium cylindrical shell buckling strength. The proposed framework involves an integration of finite element method and various machine learning techniques. The dataset obtained from the eigenvalue buckling analysis of 350 numerical simulations using ANSYS workbench 2022; however, the FE simulation of ten ring-stiffened cylindrical specimens was initially substantiated by experimental work conducted in the literature. 350 sample specimens were categorized into seven groups based on the no. of stiffeners varying from …

Exemplary Studies On The Torsional Response Of Single Pile In Contaminated Sand, Ahmed Nasr, Waseim Azzam, Nada Ramadan

Journal of Engineering Research

Deep foundations, including piles, are employed in types of coastal soil because the soil in such regions may be subjected to several variables that alter the engineering features of the soil, like oil contamination. Together with the loads caused by supported superstructures, the pile foundations may also be susceptible to torsional loads from eccentric, horizontal loads brought on by winds, earthquakes, ship accidents, and waves. Tests have been conducted in this laboratory investigation to examine the behavior of piles under torsional load (T) in polluted sandy soil. Also, tests investigated how the Lp/Dp ratio affected the piles' bearing capacity. Details …

Enhancing Bridge Resilience And Overheight Vehicle Mitigation Through Innovative Sacrificial Cushion Systems, Aly Mousaad Aly, Marc Hoffmann

Faculty Publications

Transportation departments have made significant strides in addressing the challenges posed by the increasing weights of trucks on bridges. While there is a growing awareness of overheight vehicle collisions with bridges, implementing effective countermeasures remains limited. The susceptibility of bridges to damage from such collisions is on the rise, further exacerbated by unpredictable lateral impact forces. This study employs nonlinear impact analysis to assess the response of an unprotected vehicle-girder model, yielding realistic deformation outcomes comparable to observed impacts on the US-61 bridge. Predictions for a truck traveling at 112.65 km/h indicate deformations of 0.229 m, 0.161 m, and 0.271 …

Performance Of Smart Shear Keys In Concrete Bridges Under Tsunami Loading: An Experimental Study, Haibin Zhang, Xinzhe Yuan, Genda Chen, Pedro Lomonaco

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bridges have recently been exposed to an increasing number of natural hazards such as earthquakes and tsunamis. These extreme events have resulted in transverse offsets, overturning moments, and even dropping-off of superstructures due to their weak connection to substructures. These outcomes are potentially prevented or mitigated by developing and deploying sliding, modular, adaptive, replaceable, and two-dimensional (SMART) shear keys as fuse elements between superstructures and substructures. The novelty of SMART shear keys is to enable an adaptive control of both the force and displacement of bridges under different types of loads. In this study, the performance of SMART shear keys …

A Vehicle-Bridge Interaction Model Considering Contact Patch Size And Vehicle Self-Generated Excitation – A Theoretical Study, Zhenhua Shi, Yahya M. Mohammed, Nasim Uddin, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents an improved theoretical damped single-axle vehicle-bridge dynamic interaction model to consider the effect of the contact patch size and motor-induced vehicle excitation. The contact patch issue is critical as it determines the minimum time step for simulation and maximum identifiable frequency, while the inclusion of the motor-induced vehicle excitation benefits the design of autonomous self-driven rather than towed vehicles. Estimations of the contact patch size for both the pneumatic tire and solid wheel scenarios are discussed. The contact patch responses, which degenerate into contact point responses when the contact patch size is assumed to be infinitely small, …

Behavior Of Concrete Mixes Using Recycled Aggregate Confined With Steel Sections, Latifa Sobhi Kassem, Adnan El-Masri, Nour Webhi

BAU Journal - Science and Technology

Recycled Concrete Aggregate (RAC) is a form of recycled concrete that has been studied for green building for the past 50 years. It can be used to create strong structures, such as seismic retrofitting of earthquake-prone structures. Studies have attempted to experimentally study the effect of using recycled aggregate in concrete, but the literature lacks the use of recycled concrete aggregate rapped with steel rings. This study examines the behavior of circular concrete columns with different percentages of recycled aggregate. It examines the behavior of a column with different percentages of recycled aggregate, one without jacketing, one with partial jacketing, …

Isolation And Characterization Of Caffeine-Degrading Bacteria From Coffee Plantation Areas In Malaysia, Elvina Clarie Dullah, Mohd Fazli Farida Asras

Makara Journal of Technology

Decaffeination by microbial degradation is currently the most optimal and low-cost approach, involving only microbial cells and/or their enzymes. The bacterium was characterized using a series of biochemical tests. Positive results were obtained from carbohydrate fermentation, citrate utilization, and catalase tests, while negative results were obtained from Voges-Proskauer (VP) and indole tests. Three different caffeine concentrations of 0.25%, 0.4%, and 2% were tested and measured through Gas Chromatography-Mass Spectrophotometry (GC-MS) analysis. The highest caffeine reduction (89.25%) was found when 0.25% caffeine was used in the media. Only a small amount of caffeine was reduced to 0.4% and 2%, with 34.78% …

Effect Of Lime Content, Curing Temperature, And Aging Condition On Low-Alkaline Concrete, Mahdi Parsa Pour, Reza Shaban Sharghi, Faezeh Nejati, Elmira Khaksar Najafi

Makara Journal of Technology

This study determines how curing temperatures, aging condition, and hydrated lime contents affect the unconfined compressive strength (UCS), modulus of elasticity, and workability of low-alkaline concrete. Samples were prepared in two different groups to determine the optimum hydrated lime content and aging conditions to assess the mutual effect of NaOH molarity and curing temperature, that is, 70 °C for 48 h or room temperature, on samples with and without lime. The results showed that the increase in hydrated lime content affected alkali concentration. The samples with lime exhibited a clear peak in UCS (6 M NaOH) compared with the continuous …

Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel

Makara Journal of Technology

Energy consumption in buildings is a crucial concern globally, prompting researchers to explore innovative solutions to mitigate its impact. This study investigates the optimization of building envelopes and roof shading systems of existing buildings in Indonesia to realize notable energy savings. Multiple scenarios were explored, with modifications to building envelopes and roof shading, highlighting the overall thermal transfer value as a key parameter. Using EnergyPlus simulations, the efficacy of natural ventilation in corridors and roof shading modifications was assessed in reducing energy consumption. The findings revealed that renovating existing buildings by optimization of the building envelope and roof shading by …

Early-Age Strength And Failure Characteristics Of 3d Printable Polymer Concrete: Numerical Modelling And Experimental Testing, Mohammad Amin Dehghani Najvani

Civil Engineering ETDs

The time-dependent rheological and early-age strength parameters of Polymer concrete (PC) were investigated. PC flow decreased, and the static yield stress and thixotropy increased as the specimen aged, while the dynamic yield stress remained unchanged. The study found that the Herschel-Bulkley model can accurately describe the PC’s rheological behavior over time. The change in cohesion strength and internal friction angle over time was observed using uniaxial unconfined compression and direct shear tests of fresh PC. A time-dependent MohrCoulomb failure criterion was established. Temperature analysis was used to determine the gel time and explain the evolution of the time-dependent early-age strength …

Analysis Of Loading Rate, Fiber Orientation And Material Composition Through Image Processing And Digital Volume Correlation In High Performance Concrete, Aidan R. Carlson

Electronic Theses and Dissertations

Ultra High Performance Concrete (UHPC) and High Performance concrete (HPC) is characterized by high compressive strength and high toughness. This is achieved through maximizing the particle packing density in the matrix and the use of fibers to reinforce the matrix, increasing the materials toughness. The interactions of fibers and the matrix during loading is quite complex and involves several different energy dissipation mechanisms. The goal of this work and this thesis is to investigate these interactions and identify any changes in material response, and hope that these changes may be useful for the design of UHPC moving forward.

In this …

Metal Organic Framework Modifications Of Structural Fibers, Marwan Al-Haik

Publications

A reinforced carbon composite can include a carbon sub­strate and a metal organic framework bonded to the carbon substrate. For example, a reinforced carbon composite can include a first layer, a second layer, and a resin adhered to the first layer and the second layer. The first layer can include a carbon substrate and a metal organic framework bonded to the carbon substrate. The second layer can include a carbon substrate and a metal organic framework bonded to the carbon substrate.