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Emisja Związków Siarki Z Procesu Wielkopiecowego, Marian Mazur, Marek Bogacki, Robert Oleniacz

Robert Oleniacz

The paper describes the problem of the presence of sulfur in the blast furnace process and identifies emission sources of sulfur compounds in this process. On the basis of the measurements and calculations, the types and quantities of these compounds emitted to the air were determined. It was found that pig iron smelting in a blast furnace causes emissions of COS, SO2 and H2S. These emissions occur by losses of blast furnace gas (COS and SO2), transport of blast furnace slag inside the furnace hall (SO2) and treatment of the slag by granulation (H2S). However, the most important are only …

Wpływ Komponentów Alkalicznych W Procesach Spiekania I Wielkopiecowym Na Technologię I Emisję Zanieczyszczeń, Marian Mazur, Ryszard Benesch, Andrzej Łędzki, Robert Oleniacz

Robert Oleniacz

The paper presents the impact of alkali metals on sintering and blast furnace processes and air pollutant emissions including particulate matter. On the basis of the balance calculations, it was found that the main source of alkali (Na2O and K2O) in the sintering process is a raw mixture unweathered. The calculations showed that the level of dust emissions from the sinter strand to a large extent depends on: the total alkali content in a mixture of sinter, ash content in coke breeze, K2O concentration in coke ash and alkalinity of the produced sinter. Alkali metals are introduced into the blast …

On Hack's Law, Riccardo Rigon, Ignacio Rodriguez-Iturbe, Amos Maritan, Achille Giacometti, David G. Tarboton, Andrea Rinaldo

Civil and Environmental Engineering Faculty Publications

Hack's law is reviewed, emphasizing its implications for the elongation of river basins as well as its connections with their fractal characteristics. The relation between Hack's law and the internal structure of river basins is investigated experimentally through digital elevation models. It is found that Hack's exponent, elongation, and some relevant fractal characters are closely related. The self-affine character of basin boundaries is shown to be connected to the power law decay of the probability of total contributing areas at any link and to Hack's law. An explanation for Hack's law is derived from scaling arguments. From the results we …

Development Of Site Characterization Simulator Specifications, Jeffrey L. Heiderscheidt

Theses and Dissertations

The purpose of this study was to develop a tool for evaluating data quality when characterizing a potentially contaminated groundwater aquifer, and to provide a basis for developing a simulator to allow environmental managers and engineers to practice and learn about the site characterization process. Specifically, this study characterized the uncertainty, estimation block size, and cost for the various methods of determining the value of each geological, hydrological, and contaminant parameter necessary to characterize a site. Research entailed identifying site characterization objectives and identifying parameters necessary to obtain those objectives. Methods of estimating each parameter were identified, then research was …

Strength Of Flexural Members Using Structural Grade 80 Of A653 Steel (Deck Panel Tests), Shaojie Wu, Wei-Wen Yu, Roger A. Laboube

CCFSS Library (1939 - present)

This second progress report describes the design of deck panel specimens for flexural tests and presents the test results of ninety-three deck panel specimens. The deck panels consisted of single and multiple hat-shaped ribs in their cross sections and were manufactured from 28, 26, and 22 gage steel sheets of Structural Grade 80 of ASTM A653 Steel. Among the ninety-three deck panel specimens, seventy-two panels were tested in simply supported and two-point loading conditions; sixteen panels were tested in simply supported and one-point loading conditions; and five panels with screws penetrating through tension flanges were tested in simply supported and …

Use Of Audible Pedestrian Signals, Kenneth R. Agent

Kentucky Transportation Center Research Report

Audible pedestrian signals are a device used to provide additional traffic control at signalized intersections to aid visually impaired pedestrians. An objective of this study was to determine the status of the use of this device and investigate possible guidelines for possible future installations of audible pedestrian signals in Kentucky. Another specific objective was to investigate the need for such signals at a number of intersections at the University of Kentucky.

The study showed that audible pedestrian signals can be used to supplement the standard pedestrian signals. However, their use must be limited to intersections with a demonstrated need and …

Fracture Mechanics Of High Strength Concrete Members, Rajendra K. Navalurkar

Dissertations

This study investigates the behavior of High Strength Concrete (HSC) under uniaxial state of stresses. Emphasis is placed on experimental evaluation of important mechanical and fracture properties. Owing to high brittleness of HSC, experimental results especially on tensile behavior have been largely limited and scarce. In this research, direct uniaxial tension tests are employed for determination of the post-peak tensile softening characteristics of HSC. The softening characteristics of high strength concrete is found to be considerably different than that of normal strength concrete (NSC). Fracture energies evaluated form the descending branch of the stress softening reveal significant drop in the …

Biodegradation And Landfill Settlement, Shailesh Pisolkar

Theses

The most widely used method for the final disposal of solid waste is landfilling, which is also economical and simpler than most other disposal systems. Long term settlement in a landfill occurs mainly due to biodegradation of the refuse which is a very slow microbiological process. However, if the rate of biodegradation is enhanced, it may be possible to achieve early stabilization, faster settlement, consequently more capacity of the landfill to handle waste.

The objective of this research is to study the effects of enhanced biodegradation on settlement and to compare these results to other models used for predicting landfill …

Solidification/Stabilization Of Petroleum Contaminated Soils With Cold Mix Asphalt Concrete, Nazhat Aboobaker

Theses

In this research Petroleum Contaminated Soils (PCSs) are recycled in Cold Mix Asphalt (CMA), to produce a useful product that can control potential environmental threats. The stability, durability, and hydraulic conductivity are three important engineering parameters that need to be considered when using petroleum contaminated soils (PCSs) in cold mix asphalt (CMA). In this research, stability, durability, and hydraulic conductivity due to the addition of six different PCSs into CMA is investigated. The stability test were performed to determine if cold mix asphalt made with petroleum contaminated soil can withstand heavy traffic. The freeze-thaw, and wet-dry tests were performed to …

Relationship Between Precipitation, Surface Runoff, And Shallow Water-Table, Manoj Patel

Theses

In this study, a model was developed to describe the relationship between precipitation, surface runoff, and shallow groundwater table in a watershed that is subjected to groundwater extraction and urbanization. Regression analysis of fourteen years (1976-1989) of time series data for precipitation, stream discharge, ground water elevation, and groundwater extraction yielded good correlation between these parameters.

Analysis of the data associated with groundwater recharge and discharge events that occurred in the watershed from 1976 to 1989 yielded a high correlation between the above cited parameters. Regression analysis utilized to predict monthly variations in groundwater elevations showed a fair correlation between …

Visual Inspection Of New Ramp Pavement At Bluegrass Airport Lexington, Kentucky, David L. Allen

Kentucky Transportation Center Research Report

Personnel from the Kentucky Transportation Center performed a visual inspection of newly constructed ramp pavement at the Bluegrass Airport in Lexington, Kentucky. The inspection was conducted in May, 1996 at the request of airport engineers. The inspection revealed a number of concrete apron slabs that had cracked. Attempts had been made (apparently by the contractor) to seal the cracks by epoxy injection. The visual inspection indicated that the epoxy may not have been performing as hoped, and that some of the cracks did not appear to be sealed. As a result, it was decided to obtain cores of the cracked …

Effect Of Bracing Stiffness On Buckling Strength Of Cold-Formed Steel Columns, Pratyoosh Gupta, George E. Blandford, S. T. Wang

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A three-dimensional second-order analysis is used to study the effect of brace stiffness on the buckling strength of cold-formed steel columns. The finite element formulation uses an iterative updated Lagrangian scheme to include the second-order geometric non-linear effects in the space frame element as well as the connection element used to model a brace. Lateral brace stiffness required to achieve full bracing for a two-dimensional column, and lateral and torsional brace stiffnesses required for a three-dimensional cold-formed steel column are studied. The strength requirement for various brace components, the effects of column initial imperfections, and the impact of varying warping …

Towards A Numerical Procedure For Composite Slab Assessment, Howard D. Wright, Milan Veljkovic

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Composite slab design relies upon adequate shear bond resistance between the steel and concrete. This is achieved by friction between the materials and the mechanical interlock of embossments pressed in the steel. The behaviour of this shear bond resistance is complex and is obtainable only from model tests. This paper explores the potential for numerical modelling to provide the required design information.

Interaction Of Flange/Edge - Stiffened Cold Formed Steel C - Sections, Colin A. Rogers, R. M. Schuster

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A revision to the Canadian Standard (S136-94)[1] and the American Specification (AISI- 89)[2], in which the procedure to calculate the effective width of an edge-stiffened compressive flange is modified, has been proposed by Dinovitzer et al.[3]. The proposal involves a change of the equations for the flange plate buckling coefficients of Case II compressive elements, which eliminates a discontinuity in the effective width formulation. The modified local buckling procedure was compared with the current Canadian Cold Formed Steel Standard using a program of beam tests at the University of Waterloo[4] and data available in the literature[8,9, 10, 11,12]. Statistical results …

Effective Width Of A Simple Edge-Stiffener Subjected To A Stress Gradient, Colin A. Rogers, R. M. Schuster

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The most recent editions of the North American Design Standards present a unified effective width approach for the design of compressive elements. This paper outlines a comparison of various modifications to the existing procedure used to calculate the effective width of a simple edge-stiffener subjected to a stress gradient. The comparison involves three methods where the magnitude of the compressive stress is altered, and two stress gradient methods where the plate bucking coefficient is based on the ratio of compressive stresses at the top and bottom of the flat width of the simple edge-stiffener. Analysis of these methods was carried …

The Effects Of Perforation Length On The Behaviour Of Perforated Elements In Compression, J. Rhodes, M. Macdonald

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The compressional behaviour of stub columns having perforations in the form of slots of different length is examined on the basis of testing. Plain channels of a specified geometry are considered, and the geometry examined follows that of a test programme previously carried out to examine the effects of perforation location on stub column strength. Two different perforation layouts, and two material thicknesses are considered and systematic variation in the slot length is carried out for each layout and thickness. It is found that the stub column compression capacity reduces as the perforation length increases. The test results are compared …

The Modulus Of Elasticity Of Steel - Is It 200 Gpa?, Mahen Mahendran

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In cold-formed steel construction, the use of a range of thin, high strength steels (0.35 mm thickness and 550 MPa yield stress) has increased significantly in recent times. A good knowledge of the basic mechanical properties of these steels is needed for a satisfactory use of them. In relation to the modulus of elasticity, the current practice is to assume it to be about 200 GPa for all steel grades. However, tensile tests of these steels have consistently shown that the modulus of elasticity varies with grade of steel and thickness. It was found that it increases to values as …

Buckling Experiments On Hollow Flange Beams With Web Stiffeners, Mahen Mahendran, P. Avery

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A new cold-formed and resistance welded section known as the Hollow Flange Beam (HFB) has been developed recently in Australia. In contrast to the common lateral torsional buckling mode of I-beams, this unique section comprising two stiff triangular flanges and a slender web is susceptible to a lateral distortional buckling mode of failure involving lateral deflection, twist and cross-section change due to web distortion. This lateral distortional buckling behaviour has been shown to cause significant reduction of the available flexural strength of HFBs. An investigation using finite element analyses and large scale experiments was carried out into the use of …

Determination Of Purlin R-Factors Using A Non-Linear Analysis, Catherine J. Rousch, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In both Australia and the U.S.A., the design procedure for purlins under wind uplift loading is based on the use of reduction factors (R-factors), which allow for the flexural-torsional or nonlinear twisting behaviour of purlins with screw-fastened sheeting. To date, all R-factors have been determined by testing. However, in the future it may be more efficient to obtain R-factors from numerical models to minimise testing. This paper shows how a numerical model of the twisting behaviour of channel and Z-section purlins can be used to generate R-factors. Comparisons between experimentally determined and numerically based R-factors are made.

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

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Golden Anniversary of the AISI Specification - The 1996 AISI Specification - A New AISI Cold-Formed Steel Design Manual - Design of Cold-Formed Steel Stiffened Elements with Multiple Longitudinal Intermediate Stiffeners - A Probablistic Examination of the Ultimate Strength of Cold-Formed Steel Elements - Effective Width of a Simple Edge-Stiffener Subjected to Stress Gradient - The Effects of Perforation Length on the Behaviour of Perforated Elements in Compression - Interaction of Flangel/Edge-Stiffened Cold-Formed Steel C-Sections - Cold-Formed Steel Flat Width Ratio Limits, d/t and d/w - Comparison of the Distortional Buckling Method for Flexural Members with Tests - Design of …

Design Of Thin-Walled Beams For Distortional Buckling, C. Jiang, J. Michael Davies

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The bending behaviour of cold-formed steel beams is far from simple. The double symmetry associated with hot-rolled I-sections is generally uneconomical and the use of thin-walled slender elements means that local buckling of parts of the cross-section in compression may be a significant design factor leading to additional asymmetry of behaviour. Furthermore, the modern tendency to introduce additional folds in order to control local buckling and to produce more favourable global section properties also serves to aggravate the tendency towards distortional buckling. Generalised Beam Theory (GBT) has wide application to the analysis and design of cold-formed beams and can provide …

A New Aisi Cold-Formed Steel Design Manual, Richard C. Kaehler, Paul A. Seaburg

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The Specification Committee of the American Iron and Steel Institute is currently developing a new Cold Formed Steel Design Manual. The work is being done under contract with Computerized Structural Design with oversight provided by AISI Subcommittee 26 - Design Manual. This paper describes the purpose and contents of this Manual. It is expected the Manual will be published in conjunction with the new edition of the Specification for the Design of Cold-Formed Steel Structural Members early in 1997. The Manual will contain the combined versions of the Allowable Stress Design and Load and Resistance Factor Design Specifications in addition …

Golden Anniversary Of The Aisi Specification, Wei-Wen Yu, Don S. Wolford, Albert L. Johnson

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The use of cold-formed steel members in building construction began in about the 1850's in the United States and Great Britain. However, such thin-walled steel members were not widely used for buildings until after 1946 When the first edition of the Specification for the Design of Light Gage Steel Structural Members was published by the American Iron and Steel Institute (AISI, 1946). This first design standard was based primarily on the research work sponsored by the Institute at Cornell University under the direction of Professor George Winter after 1939 (Winter, 1959a and 1959b). It was revised subsequently by the AISI …

The 1996 Aisi Specification, Roger L. Brockenbrough

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The first edition of the AISI specification was adopted in 1946. Thus, the new specification represents fifty years of progress in the formal structural application of cold-formed steel. The continued efforts of the Committee on Specifications and the sponsorship of the American Iron and Steel Institute have made this fifty years of progress in cold-formed steel a reality. The new specification combines ASD and LRFD provisions in a single document. This affords the design engineer the opportunity to become familiar with both methods and facilitates the use of whichever method is preferred. In addition, the new specification includes a number …

A Probabilistic Examination Of The Ultimate Strength Of Cold-Formed Steel Elements, Benjamin W. Schafer, Mircea Gigoriu, Teoman Pekoz

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper investigates the ultimate strength of cold-formed steel plates in uniform compression and pure bending with the goal of determining the statistical characteristics (mean and variance) of the ultimate strength. Plate thickness, longitudinal residual stress magnitude, and imperfection magnitude are considered as random variables. Based on existing data appropriate distributions are determined for these three random variables. Using ABAQUS for the strength prediction, two methods: Monte Carlo simulation and Taylor series approximation, are employed to determine statistical characteristics of the plates. The results are compared to the deterministic approach of the AISI Cold-Formed LRFD Specification.

Design Of Cold-Formed Steel Stiffened Elements With Multiple Longitudinal Intermediate Stiffeners, Benjamin W. Schafer, Teoman Pekoz

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Current specification procedures for calculating the bending strength of members with multiple longitudinal intermediate stiffeners in the compression flange have been found to be inadequate. A new procedure for calculating the effective width of stiffened elements with multiple intermediate stiffeners is presented. The new method introduces the calculation of a buckling coefficient for overall buckling of the entire stiffened element as a unit, and local buckling of the subelement plates between stiffeners. The expression for calculating overall buckling is derived and verified via comparison to numerical methods. The minimum buckling coefficient from the two modes (local and overall) is used …

Additional Design Considerations For Bolted Connections, Roger A. Laboube, Wei-Wen Yu

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A multi-year study was conducted at the University of Missouri-Rolla which focused on such topics as deformation characteristics of bearing type connections; strength of bearing and tensile type failure modes of flat sheet connections; tensile strength of staggered bolt patterns in flat sheet connections; and tensile strength of bolted connections for angle and channel sections. The intent of this research was to verify the present design approach for bolted connections and to expand the design methodology to include additional limit states, in particular the effect of deformation of the bolt hole and the influence of shear lag in angle and …

Performance Of Self-Tapping Screws In Lap-Shear Metal-To-Metal Connections, Reynaud Serrette, Victor Lopez

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The basic design requirement for screws in light gauge steel construction is the strength of the screw in a given application (metal-to-metal, wood-to-metal, or metal-to-wood) based on the body diameter of the screw. This statement is clearly obvious from the current AISI screw specifications for lap shear metal-to-metal connections. Recent research has shown that the performance of a screw fastener may also depend on other features of the screw including the head and thread style, and the method of installation (stripped versus unstripped screws). The data presented in this paper address these issues for lap shear connections designed with No. …

Shear Behavior Of Self Drilling Screws Used In Low Ductility Steel, Randy L. Daudet, Roger A. Laboube

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The results of 264 shear tests conducted on self drilling screws are presented. The tests conducted include single screws in single shear, two screws in single shear, and single screws in double shear. The performance and behavior of self drilling screws in low ductility steel are compared to the performance and behavior of screws in normal ductility steel. Results are compared to the 1986 AISI specification with 1989 addenda, and the recently approved AISI specification for self drilling screws which will be included in the next edition of the AISI code. Also, new equations are presented for the tilting/bearing limit …

Cold-Formed Steel Design By Spreadsheet Program, Scott A. Burns

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper demonstrates how to use advanced features of a spreadsheet program to design cold-formed steel members efficiently. The example presented in the paper concerns a hat section in flexure which is to be designed for maximum bending strength with a restriction on the total amount of steel that can be used. The nature of the formulas and data entered into the spreadsheet program are presented.