Architecture Commons^™

Biological Fixed-Film Systems, Mark W. Fitch, Natalie Pearson, Gene Richards, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Natural Treatment And On-Site Processes, Kevin D. White, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Contribution Of Externally Bonded Frp To Shear Capacity Of Rc Flexural Members, Ahmed Khalifa, William J. Gold, Antonio Nanni, M. I. Abdel Aziz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber reinforced polymer (FRP) materials are continuing to show great promise for use in strengthening reinforced concrete structures. These materials are an excellent option for use as external reinforcing because of their light weight, resistance to corrosion, and high strength. Externally bonded FRP sheets have been used to increase moment capacity of flexural members and to improve confinement in compression members. Investigations into the use of externally bonded FRP sheets for shear strengthening have also been conducted and have been shown to be viable. The objectives of this study were to review the current research on shear strengthening with FRP …

The Structural Behavior Of Homogeneous And Hybrid Stub Columns Under Dynamic Loading Conditions, Chi Ling Pan, Wei Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It has been recognized that the mechanical properties of sheet steels and the structural strength of cold-formed steel members can be influenced by strain rate. For studying the local and postbuckling behavior of the stiffened and unstiffened compression elements under dynamic loading condition, 97 stub columns which were assembled from the same material have been tested under different strain rates. In order to study the structural behavior of hybrid cold-formed stub columns, a total of 144 specimens were investigated. In addition, 52 drop silo tests of stub columns were conducted at General Motors Corporation (GM). The results showed that the …

Optimizing Multiagent, Multi-Injected Swell Modifier, Marshall B. Addison, Thomas M. Petry

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Interactions of expansive clay soils with transportation facilities have caused billions of dollars of damage. In the process of determining agents and methodologies to overcome expansive clay behavior, multiple injections of chemical agents into the subgrade to modify clay behavior are most promising. A study was conducted to optimize a potassium-rich solution of four parts. The modifying solution has been injected into expansive clay subgrades with success since the early 1970s. A laboratory methodology was developed to inject specimens multiple times and to conduct swell tests. Screening tests were conducted to evaluate linear effects that each of the four constituents …

Hybrid Control Of Seismic Structures With Optimal Placement Of Control Devices, Franklin Y. Cheng, Hongping Jiang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A theoretical study is carried out for optimal controller placement and effectiveness of a hybrid seismic response control system comprising a viscous fluid damper and a servovalve-controlled hydraulic actuator. A stochastic seismic response of controlled structures is first investigated with nonorthogonal damping and stiffness; then a statistical method for optimal placement of control devices on seismic-resistant structures is developed. With such placement, a hybrid system can achieve greater performance in that much less control force is required to reduce structural seismic response to a given level. This study also shows the hybrid system is superior to both active and passive …

Recent Research And Developments In Cold-Formed Steel Framing, Roger A. Laboube, Wei Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent research studies at the University of Missouri-Rolla (UMR) have focused on developing a better understanding of the behavior of cold-formed steel members and truss assemblies. This research was initiated by the more widespread use of cold-formed steel in the residential construction market, and the need to provide structurally reliable, as well as highly economical design solutions. Steel trusses are commonly assembled using C-shaped sections and self-drilling screws. Based on UMR findings, appropriate design recommendations have been proposed for the web and chord members of a truss. Also of concern is the introduction of large holes in the webs of …

Maine Guide To Energy Efficient Residential Construction : A Manual Of Accepted Practices, State Of Maine Energy Conservation Division

Maine Collection

Maine Guide to Energy Efficient Residential Construction : A Manual of Accepted Practices

State of Maine Energy Conservation Division, Department of Economic and Community Development, 59 State House Station, Augusta, Maine 04333-0059

Second Edition - November, 1997

Contents: Dedication / Acknowledgements / Introduction / Part 1. Summary of Maine's Residential Energy Standards / Part 2. Siting and Initial Design Considerations / Part 3. Important Considerations for the Design Phase / Part 4. Recommended Construction Practices / Appendixes

Life-Cycle Cost Design Of Deteriorating Structure, Dan M. Frangopol, Kai-Yung Lin, Allen C. Estes

Architectural Engineering

A lifetime optimization methodology for planning the inspection and repair of structures that deteriorate over time is introduced and illustrated through numerical examples. The optimization is based on minimizing the expected total life-cycle cost while maintaining an allowable lifetime reliability for the structure. This method incorporates: (a) the quality of inspection techniques with different detection capabilities; (b) all repair possibilities based on an event tree; (c) the effects of aging, deterioration, and subsequent repair on structural reliability; and (d) the time value of money. The overall cost to be minimized includes the initial cost and the costs of preventive maintenance, …

Lifetime Bridge Maintenance Strategies Based On System Reliability, Dan M. Frangopol, Allen C. Estes

Architectural Engineering

This study proposes a methodology for a system reliability-based condition evaluation of existing highway bridges. The approach is illustrated for an existing steel bridge located in Colorado. USA. An optimum lifetime repair strategy based on minimum expected cost is developed. The initial optimum repair strategy is updated using both biennial visual inspections and specific non-destructive evaluation testing.

Uptake And Metabolism Of Atrazine By Poplar Trees, Joel Gerard Burken, Jerald L. Schnoor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hybrid Poplar Trees Can Uptake, Hydrolyze, and Dealkylate Atrazine to Less Toxic Metabolites. in Whole Plant Studies, the Parent Compound Atrazine and 14C Ring-Labeled Metabolites Were Extracted from Poplar Tissues and Analyzed Via High-Pressure Liquid Chromatography (HPLC) with UV and Radiochromatographic Detectors in Series. the Concurrent Separation and Identification of These Metabolites Has Not Been Previously Reported in Higher Plants for Phytoremediation Applications. Unidentified Metabolites Were Also Detected. Metabolism of Atrazine Occurred in Poplar Roots, Stems, and Leaves and Became More Complete with Increased Residence Time in Tissues. in Poplar Cuttings Exposed to Atrazine for 50 Days, the Parent Compound …

Reliability Of Reinforced Concrete Girders Under Corrosion Attack, Dan M. Frangopol, Kai-Yung Lin, Allen C. Estes

Architectural Engineering

Corrosion of reinforcement is a major problem affecting a large number of reinforced concrete structures. At present, most reliability-based design studies of reinforced concrete structures do not consider the effects of corrosion. In this paper, we present a reliability-based approach to the design of reinforced concrete bridge girders that are under corrosion attack. Both reserve and residual reliability constraints are satisfied. The approach is based on the American Association of State Highway and Transportation Officials (AASHTO) standard specifications for highway bridges and on data of chloride corrosion of steel in concrete. First, the effects of corrosion on both moment and …

Carbon Frp Strengthening Of Doubly Curved Precast Pc Shell, M. Barboni, A. Benedetti, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper a recent rehabilitation project completed in Italy using carbon fiber reinforced plastic (CFRP) unidirectional sheets is examined. This technology was selected for the strengthening of a doubly curved, precast, prestressed concrete (PC) shell. The shell was part of the roof of an industrial building and had experienced severe localized damage due to accidental heat radiating from a flue. The selection of the CFRP system involved the screening of different repair procedures with relation to the constraints imposed by the owner: limited disturbance to the industrial process, safety of the occupants, low cost, and durability. In addition, the …

Multiobjective Optimization Design With Pareto Genetic Algorithm, Franklin Y. Cheng, Dan Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a constrained multiobjective (multicriterion, vector) optimization methodology by integrating a Pareto genetic algorithm (GA) and a fuzzy penalty function method. A Pareto GA generates a Pareto optimal subset from which a robust and compromise design can be selected. This Pareto GA consists of five basic operators: reproduction, crossover, mutation, niche, and the Pareto-set filter. The niche and the Paretoset filter are defined, and fitness for a multiobjective optimization problem is constructed. A fuzzy-logic penalty function method is developed with a combination of deterministic, probabilistic, and vague environments that are consistent with GA operation theory based on randomness …

Performance-Based Testing Of Chemical Stabilizers, Thomas M. Petry

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chemical stabilizing agents have been introduced that have performed in field applications to improve the behavior of earth materials. The same agents and materials subjected to standardized laboratory tests have often resulted in no improvement. For example, the tests often require pulverization of materials to finer states than are needed in the field or may require remolding when field applications are done in situ, as with injection applications. Some of the physical tests do not place treated materials in a situation resembling conditions in the field, yet they are applied to determine the use of these agents. The experiences of …

Cold-Formed Steel Webs With Openings: Summary Report, Roger A. Laboube, Wei-Wen Yu, J. E. Langan, M. Y. Shan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Based on a 3-year study that focused on the behavior of cold-formed steel beams with web openings, researchers at the University of Missouri-Rolla have developed simple, easy to apply design recommendations. The design recommendations address the limit states of web buckling resulting from bending, shear, web crippling, combined bending and shear, and combined bending and web crippling. The recommendations were developed based on the results of experimental and analytical studies of C-section beams. The C-sections, which are commonly used for wall studs and floor joists, are manufactured with web openings. Common web opening sizes are 38 x 102mm and 19 …

University Of Missouri-Rolla Research On Cold-Formed Steel Structures, Wei Wen Yu, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

During the past 27 years, numerous research projects have been conducted at the University of Missouri-Rolla (UMR) under the sponsorships of the American Iron and Steel Institute, National Science Foundation, American Society of Civil Engineers, Metal Building Manufacturers Association, Steel Deck Institute, Metal/Lath Steel Framing Association, Chromium Center, Nickel Development Institute, and several steel companies located in the USA, Canada, and South Africa. The purpose of these investigations has been to study the structural strength of cold-formed steel members, connections, and structural systems. Some of the research findings have been used in the development of the AISI Specification for the …

Environmental Contamination By Trace Metals At The Inactive Pacific Mine Site, American Fork Canyon: Legal And Remediation Implications, Phyllis Ann Bustamante

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Over the next decade, the environment will be the most important issue facing the minerals industry (Ary, 1990). Mining and its associated activities can be a source of considerable environmental damage (Table 1 ). Mining activities can cause surface and ground water pollution , damage the land and subsurface strata, and destroy terrestrial and aquatic habitat. While mining contributes to environmental degradation , it may be considered a necessary activity because it provides natural resources with a variety of commercial uses.

Nonlinear Lateral Pile Deflection Prediction In Sands, Shamsher Prakash, Sanjeev Kumar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A method has been developed to predict the load-displacement relationship for single piles subjected to lateral load, embedded in sands, considering soil nonlinearity using subgrade reaction. This is the first systematic study to develop lateral load-deflection curves using modulus degradation with strain. Based on the analysis of 14 full-scale lateral pile-load tests, an empirical equation of modulus degradation with strain and a range of k hmax values, i.e., k h at 0.002 strain at 1 m (3.28 ft) depth, has also been proposed. An example problem is included to demonstrate its use. Based on this method, the computed load deflections …

On Seismic Displacements Of Rigid Retaining Walls, Yingwei Wu, Shamsher Prakash

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Rigid retaining walls experience both sliding and rocking displacement during earthquakes. Richards and Elms' (1979) method incorporates only sliding displacements in design. A realistic method of computing both sliding and rocking displacements of the walls based on nonlinear soil properties both for the base soil and backfill was developed by Rafnsson and Prakash (1994). A design procedure based on this method was then developed by Prakash. et al (1995, b). Comparisons of the displacements of typical walls by both the methods have been made. Also, typical field data from recent earthquakes has been analyzed to compare the observed displacements with …

Bending And Shear Behavior Of Web Elements With Openings, M. Y. Shan, Roger A. Laboube, Wei-Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Cold-formed steel C-sections are frequently used as wall studs and floor joists in both commercial and residential construction. To facilitate installation of ancillary systems such as electrical wiring and plumbing, the C-section is manufactured with a web opening. Although the opening offers construction advantages, it may degrade the structural integrity of the member. To quantify the degrading effect of a web opening, a study has been conducted at the University of Missouri-Rolla (UMR). The UMR study included the loading conditions of bending, shear, web crippling, and the combinations thereof. This paper summarizes the results of an experimental study which addressed …

Effects Of Accelerated Weathering On Architectural Laminated Glass In A Windstorm Environment, Richard A. Behr, Joseph E. Minor, Paul A. Kremer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An experimental study was conducted to assess the serviceability and ultimate limit state behavior of a fully glazed architectural laminated glass system under accelerated weathering conditions. Glazed specimens included heat-strengthened laminated glass with a low-emissivity, metallic solar coating on one glass surface next to the polyvinyl butyral interlayer. The laminated glass units were anchored to the aluminum curtain wall frame with a perimeter anchor bead of medium-modulus structural silicone sealant. Accelerated weathering was performed in a manner similar to the provisions of ASTM E773-88 and E774-92. All specimens (weathered and unweathered) were then subjected to a severe windstorm simulation test, …

Seismic Test Methods For Architectural Glazing Systems, Richard A. Behr, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An ongoing effort is being made at the University of Missouri-Rolla to develop standard laboratory test methods and codified design procedures for architectural glass under seismic loadings. Recent laboratory work has yielded some promising results regarding the development of an appropriate seismic test method for architectural glass, as well as identifying ultimate limit states that quantify the seismic performance and damage thresholds of various glass types. Specifically, a straightforward "crescendo-like" in-plane dynamic racking test, performed at a constant frequency, has been employed successfully. Two ultimate limit states for architectural glass have been defined: (1) a lower ultimate limit state corresponding …

Degradation Of Trichloroethylene By Methanol-Grown Cultures Of Methylosinus Trichosporium Ob3b Pp358, Mark W. Fitch, G. E. Speitel, G. Georgiou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A Soluble Methane Monooxygenase-Constitutive Mutant Strain of Methylosinus Trichosporium OB3b, Strain PP358, Was Grown with Methanol as the Carbon Source, and the Kinetics of Trichloroethylene (TCE) Degradation Were Determined. PP358 Exhibited High TCE Degradation Rates under Both Oxygen- and Carbon-Limiting Conditions. the Optimal Pseudo First-Order Rate Constant for TCE Was Comparable to the Values Measured for Cells Grown with Methane. We Found that Growth under Oxygen-Limiting Conditions Results in Increased Accumulation of Polyhydroxybutyrate, Which in Turn Correlates with Higher Transformation Capacities for TCE. It Was Also Shown that Methanol Inhibits TCE Degradation Only at High Concentrations. Thus, Methanol-Grown Cultures of …

Phytoremediation: Plant Uptake Of Atrazine And Role Of Root Exudates, Joel G. (Gerard) Burken, Jerald L. Schnoor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phytoremediation is an Emerging Technology for Degradation of Organic Chemicals. the Potential of Phytoremediation in the Cleanup of Contaminated Sites and Prevention of Non-Point-Source Pollution Was Examined with the Pesticide Atrazine in Two Experimental Systems. Uptake Was Determined in Batch Experiments with 14C Ring-Labeled Atrazine and Hybrid Poplar Trees Grown in Two Soil Types. Mineralization Was Studied Utilizing Soil Microcosms with the Addition of Root Exudates. Results Indicate that Poplar Cuttings Were Able to Uptake the Majority of Applied Atrazine that Was Not Tightly Sorbed to the Organic Fraction of the Soil, with No Detectable Adverse Effects to the Trees. …

Performance Of Laminated Glass Units Under Simulated Windborne Debris Impacts, Richard A. Behr, Paul A. Kremer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Severe windstorm events such as Hurricane Andrew in 1992 have underscored the vulnerability of building envelopes to breaching under the combined effects of windborne debris impacts and wind pressures. Damage to building interiors and disruption of building functions are exacerbated greatly when building envelopes are breached. When the inner glass ply in a laminated glass window unit is unbroken, the integrity of that part of the building envelope is preserved - provided that the inner glass ply has sufficient resistance to subsequent positive and negative wind pressures. In an effort to develop glazing systems that are resistant to breaching due …

Behavior Of Low Ductility Steels In Cold-Formed Steel Connections, S. Seleim, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Accepted design approaches for the strength of a steel connection rely on adequate ductility of the connected parts. In cold-formed steel connection design, adequate ductility is defined by the Specification for the Design of Cold-Formed Steel Members. To assess the influence of low ductility steels, i.e. steels not meeting the specification ductility requirements, single lap bolted connections were studied. The experimental study reflected key connection strength parameters: edge distance, sheet thickness, sheet width, bolt pattern, Fu/Fy, and percentage elongation. Test results indicate that failure modes in low ductility steels are inconsistent with observed failure modes in adequate ductility steels. It …

Multiobjective Optimization Of Structures With And Without Control, Franklin Y. Cheng, Dan Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A multiobjective optimization algorithm is introduced, and the effect of different objective functions on structural design is investigated. The basic idea of this approach is to support the decisionmaker by directly selecting the best compromise solution from the Pareto optimal solutions. A payoff matrix is first constructed by optimizing each objective function subject to the given constraints; a substitute function is then formed. Under the original constraint conditions, maximizing the substitute function gives the best compromise solution. This research shows that multiobjective optimization should be carried out to obtain a rational structural design. Two structural optimal design examples - one …

Computer Simulations Versus Real Experiments In A Portable Structural Mechanics Laboratory, Richard A. Behr

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Efforts are being made to develop practical and effective innovations for undergraduate engineering teaching laboratories. The 'ANEX' process, in which computer simulations are compared in nearly real time with physical measurements made on bench-scale model experiments, is now being used successfully in an introductory structural analysis course. ANEX is described, as well as current plans to develop software simulation modules and matched, bench-scale model experiments for new 'MECH-ANEX' laboratory applications in lower-division statics and mechanics of materials courses. The ANEX process could also be adapted to undergraduate laboratory applications in a wider range of engineering and science disciplines.

Development Of A Loading History For Seismic Testing Of Architectural Glass In A Shop-Front Wall System, C. P. Pantelides, K. Z. Truman, Richard A. Behr, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Moderate earthquakes can pose significant threats to the serviceability and structural integrity of the architectural glazing systems that are included in most building envelope systems. Building envelope damage can cause considerable economic losses due to operational disruptions for extended periods following an earthquake. Furthermore, glazing system structural failures are potentially hazardous to both building occupants and pedestrians. In this paper a systematic analytical study of the effect of the SOOE component of the 1940 El Centro earthquake on the response of a one-storey glass and aluminum shop-front wall system is presented. The seismic response of a one-storey commercial building comprised …