Architecture Commons^™

Strain-Controlled Cyclic Simple Shear Tests On Sand With Radial Strain Measurements, Xin Kang, Louis Ge, Kuang Tsung Chang, Annie On Lei Kwok

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Strain-controlled cyclic simple-shear tests were performed on silica sand with radial strain measurements. The specimens were tested under a constant K0 condition and subjected to cyclic loading and post cyclic monotonic loading. Threshold cyclic shear strain, volumetric strain, secant shear modulus, and damping ratio are investigated. Generally, the volumetric strain behavior in this study agreed well with literature findings that were investigated using the conventional cyclic direct simple shear test (without radial constraints). Radial strain during monotonic simple shear (post cyclic loading) was found to be a good parameter in monitoring the onset of flow slide in cohesionless soil. The …

Model For Coupled Large Strain Consolidation And Solute Transport In Layered Soils, Hefu Pu, Patrick J. Fox

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A numerical model, called CST3 (Consolidation and Solute Transport 3), is presented for coupled one-dimensional large strain consolidation and solute transport in layered soils. The consolidation algorithm accounts for vertical strain, soil self-weight, general constitutive relationships, relative velocity of fluid and solid phases, changing compressibility and hydraulic conductivity during consolidation, unload/reload, time-dependent loading and boundary conditions, external hydraulic gradient, variable preconsolidation stress profiles, and multiple soil layers with different material properties. The solute transport algorithm accounts for advection, diffusion, mechanical dispersion, linear and nonlinear sorption, equilibrium and nonequilibrium sorption, porosity-dependent effective diffusion coefficient, and first-order decay reactions. CST3 is based …

Post-Repair Seismic Assessment Of Rc Bridges Damaged With Fractured Column Bars - A Numerical Approach, Ruili He, Yang Yang, Lesley H. Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Seismic repair of reinforced concrete (RC) bridge columns has been studied extensively during the past several decades; however, few studies have been conducted on the influence of the column repair (member level) on the post-repair performance of bridge structures (system level). In a previous experimental study by the authors, a method was developed to rapidly repair severely damaged RC bridge columns to enable the quick reopening of the bridge to emergency traffic. Thus, a lower limit state was used for the repair design, so that the lateral strength and drift capacity of a repaired RC column with fractured longitudinal bars …

Evaluation Of Carbonation Resistance Of Paint Coated Concrete For Buildings, Tommy Y. Lo, Wenyu Liao, C. K. Wong, Waiching Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When evaluating the carbonation resistance of paint coated concrete, the effects of both the strength grade and the curing conditions (standard curing and accelerated curing) of concrete substrate on carbonation resistance of paint coated concrete were investigated. The concept of the carbonation suppression ratio of paint was presented for evaluation of the anti-carbonation performance of the two types of paints (exterior and interior paints) when applied to a reference concrete substrate. The test results showed a good linear relationship between the carbonation depths of the paint coated concrete and the square root of exposure times. Concrete with higher strength grade …

Engineering Behavior And Characteristics Of Water-Soluble Polymers: Implication On Soil Remediation And Enhanced Oil Recovery, Shuang Cindy Cao, Bate Bate, Jong Wan Hu, Jongwon Jung

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Biopolymers have shown a great effect in enhanced oil recovery because of the improvement of water-flood performance by mobility control, as well as having been considered for oil contaminated-soil remediation thanks to their mobility control and water-flood performance. This study focused on the wettability analysis of biopolymers such as chitosan (85% deacetylated power), PEO (polyethylene oxide), Xanthan (xanthan gum), SA (Alginic Acid Sodium Salt), and PAA (polyacrylic acid), including the measurements of contact angles, interfacial tension, and viscosity. Furthermore, a micromodel study was conducted to explore pore-scale displacement phenomena during biopolymer injection into the pores. The contact angles of biopolymer …

The Bridge Newsletter Spring 2016, Missouri University Of Science And Technology

The Bridge Newsletter

-Steel Bridge Team qualifies for nationals
-Concrete, reimagined
-Going with the flow
-Remembering Vernon T. Jones

2016 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

No Reduction By Propane Over Monolithic Cordierite-Based Fe/Al2o3 Catalyst: Reaction Mechanism And Effect Of H2o/So2, Hao Zhou, Yaxin Su, Wenyu Liao, Wenyi Deng, Fangchuan Zhong

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The selective reduction of NO by C₃H₈and the sensitivity to H₂O and SO₂have been studied over monolithic cordierite-based Fe/Al₂O₃catalysts, which were prepared by the sol–gel and impregnation method. The catalysts were investigated by N₂ adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. Results showed that NO reduction was more than 90% in the absence of oxygen at 500 °C and in the presence of oxygen at 600 °C respectively. In a continues …

Geotechnical State-Of-The-Art In Guatemala -- Ground Stabilization, Fernando Rafael Callejas Benitez

Doctoral Dissertations

"History provides an understanding of the present and in a way, a guide for the future. The state-of-the-art is often referred to as a snapshot of the most significant works and contributions made in a field of study; In this case the focus is on Guatemalan geotechnical engineering. This study presents a comprehensive description of the different events that impulse geotechnical engineering in Guatemala.

As part of the description of the state-of-the-practice an investigation of the different human (engineers/contractors) and physical resources (laboratories/field equipment) and their capabilities are presented. An overview of the civil engineering programs is presented. Then, the …

An Introduction To The Special Issue On Geoscience Papers Of The Future, Cédric H. David, Yolanda Gil, Christopher J. Duffy, Scott D. Peckham, S. Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Advocates of enhanced quality for published scientific results are increasingly voicing the need for further transparency of data and software for scientific reproducibility. However, such advanced digital scholarship can appear perplexing to geoscientists that are seduced by the concept of open science yet wonder about the exact mechanics and implications of the associated efforts. This special issue of Earth and Space Science entitled "Geoscience Papers of the Future" includes a review of existing best practices for digital scholarship and bundles a set of example articles that share their digital research products and reflect on the process of opening their scientific …

Properties Of Self-Compacting Concrete With Recycled Coarse Aggregate, W. C. Tang, P. C. Ryan, H. Z. Cui, W. Liao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The utilization of recycled concrete aggregate (RCA) in Self-Compacting Concrete (SCC) has the potential to reduce both the environmental impact and financial cost associated with this increasingly popular concrete type. However, to date limited research exists exploring the use of coarse RCA in SCC. The work presented in this paper seeks to build on the existing knowledge in this area by examining the workability, strength, and fracture properties of SCCs containing 0%, 25%, 50%, 75%, and 100% coarse RCA. The experimental programme indicated that at RCA utilization levels of 25% to 50% little or no negative impact was observed for …

Assessing Downstream Stormwater Impacts For Urban Watershed Planning, Johanna Meyer Pavlowsky

Masters Theses

"The urbanization of watersheds has caused debilitating effects to downstream aquatic ecosystems in catchments and streams. The implementation of green infrastructure (GI), such as permeable pavements and bioretention facilities, has been shown to alleviate these effects by both reducing runoff and mitigating pollutants; however, the implements are often not designed with a specific goal of water improvement. This study targets understanding a small, impaired urban watershed, and the benefits green infrastructure may have to provide environmental, social, and economic improvement to the watershed.

Portions of Rolla including much of the S&T campus drain into the impaired urban waterbody Frisco Lake, …

Pumping Of Fresh Concrete: Insights And Challenges, Geert De Schutter, Dimitri Feys

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pumping of Fresh Concrete is of Utmost Importance for Concrete Practice. Required Pumping Pressures Are Typically Estimated based on Design Charts. However, with the Increased Use of Chemical Admixtures and the Development of More Flowable Concrete Mixtures, the Accuracy of Traditional Design Charts is Questioned. in Recent Years, Significant Progress Has Been Obtained in Understanding the Flow of the Material in the Pumping Pipe, Including the Behavior of the Lubrication Layer Near the Pipe Surface. in Comparison with Traditional Design Charts, This Results in More Reliable Pressure Predictions When Considering Very Fluid Concrete Types Like Self-Consolidating Concrete. Some Remaining Challenges …

Analysis Of The Cost Effectiveness Of Combined Particle And Activated Carbon Filters For Indoor Ozone Removal In Buildings, Josh R. Aldred, Erin Darling, Glenn Morrison, Jeffrey Siegel, Richard L. Corsi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study involved the development of a model for evaluating the potential costs and benefits of ozone control with combined particle/activated carbon filtration (referred to here as activated carbon filtration) in buildings. The modeling effort included the prediction of indoor ozone and ozone reaction products with and without activated carbon filtration in the HVAC system. Benefitto- cost ratios were estimated for various types of buildings in 12 American cities in 5 different climate zones. Health benefits were evaluated using disability-adjusted life-years attributed to the difference in indoor ozone concentration with and without activated carbon filtration and included city-specific age demographics …

Influence Of The Substrate Characteristics On The Bond Behavior Of Pbo Frcm-Concrete Joints, Tommaso D'Antino, Lesley H. Sneed, Christian Carloni, Carlo Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber Reinforced Cementitious Matrix (FRCM) composites can be employed as a valid alternative to Fiber Reinforced Polymers (FRP) composites for strengthening existing reinforced concrete (RC) structures. The weakness of FRCM-concrete joints has been reported to be at the matrix-fiber interface rather than within the concrete substrate, as is usually reported in the case of FRP-concrete joints. The experimental investigations regarding FRCM strengthening available in the literature have been performed by applying the FRCM composite onto a surface that was treated before the application, usually by grinding or sandblasting. However, the role of the substrate characteristics on the failure mechanism of …

A Hybrid Approach For Increasing Baffling Factors In Contact Tanks, Justin J. Kattnig, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A novel approach using a hybrid combination of internal baffles and industrial packing material is investigated in order to optimize the hydraulic residence time of a 1,500-gal rectangular concrete tank. Hydraulic residence time, which is commonly classified using the baffling factor (BF), was determined from residence time distribution curves obtained using both computational fluid dynamics (CFD) simulations and physical tracer studies. CFD simulations were used to model two scenarios. The first scenario was a base system consisting of an unbaffled concrete tank, and the second scenario was a two-baffle system. Computational simulation results were experimentally validated via tracer studies on …

Block Sparse Memory Improved Proportionate Affine Projection Sign Algorithm, J. Liu, S. L. Grant

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A block sparse memory improved proportionate affine projection sign algorithm (BS-MIP-APSA) is proposed for block sparse system identification under impulsive noise. The new BS-MIP-APSA not only inherits the performance improvement for block-sparse system identification, but also achieves robustness to impulsive noise and the efficiency of the memory improved proportionate affine projection sign algorithm (MIP-APSA). Simulations indicate that it can provide both faster convergence rate and better tracking ability under impulsive interference for block sparse system identification as compared with APSA and MIP-APSA.

Radial Strain Behaviors And Stress State Interpretation Of Soil Under Direct Simple Shear, Xin Kang, Yao Cheng, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Radial strain behaviors and stress state interpretation methods of silica sand consolidated at different K0 values under modified direct simple shear were investigated in this research. Consolidated drained triaxial compression test, direct shear box test, and wire reinforced direct simple shear tests were conducted, and the test results were compared and linked with the modified direct simple shear tests. Based on the observed testing data, simple shear specimens with constant lateral stress exhibited relatively small radial strain during shear, especially under small shear strains. After the peak shear resistance has mobilized, radial strain increased rigorously until the specimen failed. Confining …

Benchmark Problems For Large Strain Consolidation, Patrick J. Fox, Hefu Pu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Modeling of the one-dimensional consolidation process for soil and other compressible porous media is important for a variety of engineering applications. This paper presents solutions for two benchmark problems for large strain consolidation of a saturated soil layer that can be used to check other analytical and numerical analysis methods. The solutions include effects of vertical strain, soil self-weight, nonlinear constitutive relationships, and changing material properties during the consolidation process. High-accuracy data are presented for each problem and include changes of settlement, void ratio, and excess pore pressure with time.

A Comparison Of The Bond Behavior Of Pbo-Frcm Composites Determined By Double-Lap And Single-Lap Shear Tests, Lesley Sneed, T. D'Antino, C. Carloni, C. Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the results of an investigation on the bond behavior and stress-transfer mechanism of polyparaphenylene benzo isoxazole (PBO) fiber-reinforced cementitious matrix (FRCM) composites bonded to a concrete substrate using double-lap and single-lap shear tests. Results of double-lap shear tests with different composite bonded lengths and widths are presented and compared with those from single-lap shear tests previously reported by the authors. The idealized load response developed from single-lap shear tests is found to characterize the response of the composite in double-lap shear tests, although with a few key differences. With the double-lap shear test, load redistribution among the …

Stable Isotope-Enabled Pathway Elucidation Of 2,4-Dinitroanisole Metabolized By Rhizobium Lichtii, Hunter W. Schroer, Kathryn L. Langenfeld, Xueshu Li, Hans Joachim Lehmler, Craig L. Just

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recently developed military explosives are safer to handle, but more environmentally mobile, than traditional explosives. The new insensitive munitions, including 2,4-dinitroanisole (DNAN), have been sparsely studied, making the use of bacterial and/or plant-based remediation approaches unfeasible without further information about the transformation of these compounds. To that end, Rhizobium lichtii isolated from willow tree tissues were studied and observed to completely degrade 5 mg L-1 DNAN within 24 h in liquid media with added carbon and nitrogen. The use of DNAN, [13C6] DNAN, and [15N2] DNAN enabled the identification of 11 previously unknown metabolites resulting from sulfation, acetylation, and/or methylation …

Rans Modeling Of Stably Stratified Turbulent Boundary Layer Flows In Openfoam®, Jordan M. Wilson, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Quantifying mixing processes relating to the transport of heat, momentum, and scalar quantities of stably stratified turbulent geophysical flows remains a substantial task. In a stably stratified flow, such as the stable atmospheric boundary layer (SABL), buoyancy forces have a significant impact on the flow characteristics. This study investigates constant and stability-dependent turbulent Prandtl number (Prt) formulations linking the turbulent viscosity (νt) and diffusivity (κt) for modeling applications of boundary layer flows. Numerical simulations of plane Couette flow and pressure-driven channel flow are performed using the Reynolds-averaged Navier-Stokes (RANS) framework with the standard k-ϵ turbulence model. Results are compared with …

The Bridge Newsletter Winter 2015, Missouri University Of Science And Technology

The Bridge Newsletter

-S&T’s Solar House Design Team sets out to redefine the American housing market
-A monumental anniversary
-Academy awards Sneed
-ASCE honors Holmes

Enhanced Series-Parallel Model For Estimating The Time-Dependent Thermal Conductivity Of Fly Ash Soil Mixtures, Xin Kang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An enhanced series-parallel (S-II) model of one-dimensional conductive heat flow through a unit cell was developed to estimate the time-dependent thermal conductivity of Class C fly ash stabilized soils. The unit cell is composed of three separate heat flow paths: a continuous path through solid contacts (soil contacts, fly ash contacts, and soil fly ash contacts) in parallel arrangement, a series-parallel path of solids in a series arrangement with a parallel arranged path of solid-miniscule pores (miniscule portion of solid water and miniscule portion of solid air), and a continuous path through water and air in parallel arrangement. The solid-miniscule …

Assessment Of Empirical Equations For The Compression Index Of Fine-Grained Soils In Missouri, Site Onyejekwe, Xin Kang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of correlations and empirical relationships in geotechnical engineering provides a fast, cost-effective means of predicting the value of a parameter based on the values of certain other, possibly more easily determined, parameters. The correlation between two or more soil properties has been found to be dependent in varying degrees on soil type, the testing method used to obtain the numerical value of the parameter itself and the homogeneity of the soil. Many empirical correlations among soil properties have been published. These correlations, based on widely sourced data, may not be appropriate for local situations. Hence, there is a …

Accumulation Of Gas-Phase Methamphetamine On Clothing, Toy Fabrics, And Skin Oil, G. Morrison, N. V. Shakila, K. Parker

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To better understand methamphetamine exposure and risk for occupants of former residential clandestine methamphetamine laboratories, we measured the dynamic accumulation of methamphetamine in skin oil, cotton and polyester (PE) clothing, upholstery, and toy fabric (substrates) exposed to 15-30 ppb (91-183 μg/m3) neutral methamphetamine in air for up to 60 days. The average equilibrium partition coefficients at 30% RH, in units of μg of methamphetamine per gram of substrate per ppb, are 3.0 ± 0.2 for a PE baby blanket, 5.6 ± 3.5 for a PE fabric toy, 3.7 ± 0.2 for a PE shirt, 18.3 ± 8.0 for a PE/cotton …

Chemically Stabilized Soft Clays For Road-Base Construction, Xin Kang, Gi Chun Kang, Kuang Tsung Chang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Soft clays are widely distributed in Missouri, United States. Due to their relatively low strength and high compressibility, subgrade construction in soft clays has encountered many difficulties. In recent practice, the use of fly ash (FA) along with lime to tackle soft subgrade problems has shown promising results. The effectiveness of Class C FA and lime kiln dust (LKD) in clay subgrade stabilization is examined in this research. Scanning electron microscopic (SEM) analysis, proctor compaction tests, unconfined compression tests, and resilient modulus tests were carried out on the FA and LKD modified soil mixtures. Test specimens were prepared at optimum …

Impact Of Modified Inlets On Residence Times In Baffled Tanks, Jeremy S. Carlston, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sharp inlets, although prevalent, tend to reduce mixing efficiency in hydraulic contact tanks by affecting fluid and scalar transport throughout the entire system. Superior inlets are often not an option because of the prohibitive cost of upgrading preexisting tanks. To remedy this, seven inexpensive yet easily implemented attachments to a sharp inlet were tested on a full-scale, baffled, prototypical contact tank. Cumulative residence time distributions of a conservative, passive scalar were obtained for each attachment to assess their performance. A study using computational fluid dynamics of the same tank with the various attachments was then performed to strengthen the empirical …

Recent Advances In Indoor Chemistry, Glenn Morrison

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Just as the chemistry creates urban smog and aerosols that influence climate change, chemistry in building air can alter the indoor environment for better or worse. This review focuses on chemical pathways initiated by oxidants that infiltrate from outdoor air and other indoor-sourced reactants and surfaces that make these environments unique chemical reactors. Ozone reacts with fragrance molecules, tobacco smoke residues, and even human skin oils to generate a host of oxidized organic compounds, secondary organic aerosols, and irritants. Nitrous acid is formed on indoor surfaces and is subsequently cleaved by even the relatively dim light indoor. This raises the …

On Turbulent Mixing In Stably Stratified Wall-Bounded Flows, Farid Karimpour, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, we provide an analysis of turbulent mixing in stably stratified wall-bounded flows to highlight a number of important issues such as prediction of the turbulent viscosity, the turbulent diffusivity, and the irreversible flux Richardson number. By invoking the equilibrium assumption between the production rate of the turbulent kinetic energy (P), the dissipation rate of the turbulent kinetic energy (P), and the turbulent potential energy dissipation rate (εPE) as P ≈ ε + εPE and also assuming equilibrium between the buoyancy flux (B) and εPE as -B ≈ εPE, we first propose that the irreversible flux Richardson number …