Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Missouri University of Science and Technology

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2101 - 2130 of 7869

Full-Text Articles in Civil and Environmental Engineering

Testing Of Connectors For Cold-Formed Steel Construction - Challenges, Recent Innovation, And Future Direction, Timothy M. Stauffer, Hien Kim Nguyen Aug 2012

Testing Of Connectors For Cold-Formed Steel Construction - Challenges, Recent Innovation, And Future Direction, Timothy M. Stauffer, Hien Kim Nguyen

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

As cold-formed steel construction continues to evolve, manufacturers are making advances in prefabricated connectors for use in a variety of applications. Often, establishing available strengths for connectors requires testing. This paper will examine some of the challenges associated with testing of these products. Available standards and criteria will be discussed, and an overview of potential difficulties with their use will be presented. Test programs conducted by one manufacturer during recent product development will be presented to illustrate some of the challenges and highlight innovations made to address them. Finally, based on experience gained through extensive testing and product development, recommendations …


Self-Shape Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. The Aug 2012

Self-Shape Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. The

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

This paper presents the optimisation of cold-formed steel open columns using the recently developed self-shape optimisation method that aims to discover new profile shapes. The strength of the cold-formed steel sections is calculated using the Direct Strength Method, and the rules developed in the present work to automatically determine the local and distortional elastic buckling stresses from the Finite Strip and constrained Finite Strip Methods are discussed. The rules are verified against conventional and optimum sections yielded in this research, and found to accurately predict the elastic buckling stresses. The principles behind the self-shape optimisation method are summarised herein and …


Innovative Cross-Section Shapes For Built-Up Cfs Columns. Experimental Investigation, Iveta Georgieva, Luc Schueremans, Lincy Pyl, Lucie Vandewalle Aug 2012

Innovative Cross-Section Shapes For Built-Up Cfs Columns. Experimental Investigation, Iveta Georgieva, Luc Schueremans, Lincy Pyl, Lucie Vandewalle

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

Innovative cross-section shapes for built-up columns from cold-formed steel (CFS) profiles are evaluated experimentally. The goal is to obtain highly stable members with reduced sensitivity to bucking effects and initial imperfections, and therefore, higher strength-to-weight ratios. The columns have been designed following the principles of the direct strength method [1], with the ambition to exclude (or reduce) various buckling effects from the column response to compressive loads. Cross-section proportions and bolt spacing have been adapted, in order to interfere with the distortion of individual profiles and the overall buckling of the columns. Experiments show that, through proper design and insight …


Compressive Strength Tests And Design Of Cold-Formed Plain And Dimpled Steel Columns, V. B. Nquyen, C. J. Wang, D. J. Mynors, M. A. English, M. A. Castellucci Aug 2012

Compressive Strength Tests And Design Of Cold-Formed Plain And Dimpled Steel Columns, V. B. Nquyen, C. J. Wang, D. J. Mynors, M. A. English, M. A. Castellucci

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

This paper presents the experiments and design formulae of cold-formed plain and dimpled steel columns. A series of compression tests on plain and dimpled channel columns were conducted over a range of different geometries and the strength of the columns were investigated. The change in strength of the dimpled columns resulting from the cold working associated with the dimpling process was considered. The results showed that the buckling and ultimate strengths of dimpled steel columns were up to 33% and 26% greater than plain steel columns, respectively. The test results were evaluated by comparing buckling and ultimate loads of plain …


Steel Deck Institute Standards For Composite Steel Floor Deck-Slabs, Thomas Sputo Aug 2012

Steel Deck Institute Standards For Composite Steel Floor Deck-Slabs, Thomas Sputo

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

As an ANSI accredited standards developer, the Steel Deck Institute (SDI) has developed an updated and expanded version of its “Standard for Composite Steel Floor Deck-Slabs”, ANSI/SDI C-2011 and a new standard, “Test Standard for Composite Steel Deck-Slabs”, ANSI/SDI T-CD-2011. These two standards reflect the current state-of-the-art for the design and testing of composite steel deck-slabs where the steel deck provides the tensile reinforcement for the slab. Substantial changes in the ANSI/SDI-C-2011 Standard include increased information regarding the use of fibers for concrete crack control purposes and concrete serviceability, consideration of moving and concentrated loads, and use of updated shear …


Aisi Standards Update, Helen Chen, Roger Brockenbrough, Richard Haws Aug 2012

Aisi Standards Update, Helen Chen, Roger Brockenbrough, Richard Haws

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

Since the publication of the 2007 editions, changes and additions have been made to AISI design and construction standards. Accordingly, new editions of the standards, or supplements to existing standards, will be published to formalize these changes. This paper provides an overview of the major changes and additions to those standards.


Direct Strength Method Of Design For Shear Of Cold-Formed Channels Based On A Shear Signature Curve, Gregory J. Hancock, Cao Hung Pham Aug 2012

Direct Strength Method Of Design For Shear Of Cold-Formed Channels Based On A Shear Signature Curve, Gregory J. Hancock, Cao Hung Pham

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

Thin-walled sections in compression and/or bending may undergo one of the three modes of local, distortional or overall (Euler) buckling, or combinations of these. The Semi-Analytical Finite Strip Method (SAFSM) developed by YK Cheung has been widely used in computer software (THIN-WALL, CUFSM) to develop the signature curve of the buckling stress versus buckling half wavelength for a thin-walled section under compression or bending to allow identification of these modes. The minimum points on the signature curve are now used in the Direct Strength Method (DSM) of design of cold-formed sections in the American Specification and Australian/New Zealand Standard for …


Shear Strength Of Hollow Flange Channel Beams With Stiffened Web Openings, P. Keerthan, M. Mahendran Aug 2012

Shear Strength Of Hollow Flange Channel Beams With Stiffened Web Openings, P. Keerthan, M. Mahendran

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

This LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a patented manufacturing process involving simultaneous cold-forming and dual electric resistance welding. The LSBs are commonly used as floor joists and bearers with web openings in buildings. Their shear strengths are considerably reduced when web openings are included for the purpose of locating building services. Shear tests of LSBs with web openings have shown that there is up to 60% reduction in the shear capacity. Hence there is a need to improve the shear capacity of LSBs with web openings. A cost effective way to …


The Effects Of Web Holes On Web Crippling Strength Of Cold-Formed Steel Channels Under End-Two-Flange Loading Condition, Asraf Uzzaman, James B. P. Lim, David Nash, Jim Rhodes, Ben Young Aug 2012

The Effects Of Web Holes On Web Crippling Strength Of Cold-Formed Steel Channels Under End-Two-Flange Loading Condition, Asraf Uzzaman, James B. P. Lim, David Nash, Jim Rhodes, Ben Young

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

Cold-formed steel sections are often used as wall studs or floor joists; such sections often include web holes for ease of installation of the services. Web crippling at points of concentrated, or localised, load or reaction in thin-walled beams is well known to be a significant problem, particularly in the case of beams with slender webs, and is of high importance in the field of cold-formed steel members, as such members are generally not stiffened against this type of loading. In this paper, a combination of experimental tests and non-linear elastoplastic finite element analyses are used to investigate the effect …


Push Tests On Innovative Shear Connector For Composite Beam With Cold-Formed Steel Section, S. O. Bamaga, M. M. Tahir, C. S. Tan Aug 2012

Push Tests On Innovative Shear Connector For Composite Beam With Cold-Formed Steel Section, S. O. Bamaga, M. M. Tahir, C. S. Tan

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

In this study, experimental tests were conducted to investigate the ductility and strength capacity of new shear connector. Push test specimens were prepared and tested according to EN1994-1-1 standard. The push test specimen consists of two cold-formed steel lipped channel sections oriented back-to-back to form an I-section beam, transverse metal deck and normal concrete slabs grade C25/30. Angle brackets were obtained from the same section of the beam and fastened to the web of steel beam to provide the shear connection. Two shear connectors were tested namely; “SC1” and “SC2” shear connectors. Both shear connectors showed a ductile behavior and …


Direct Strength Design Of Metal Building Wall And Roof Systems - Through-Fastened Simple Span Girts And Purlins With Laterally Unbraced Compression Flanges, Tian Gao, Cristopher D. Moen Aug 2012

Direct Strength Design Of Metal Building Wall And Roof Systems - Through-Fastened Simple Span Girts And Purlins With Laterally Unbraced Compression Flanges, Tian Gao, Cristopher D. Moen

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

A Direct Strength Method (DSM) prediction approach is introduced and validated for metal building wall and roof systems constructed with steel panels through-fastened with screws to girts or purlins. The focus is capacity prediction for simple spans under wind uplift or suction, however the DSM framework is generally formulated to accommodate gravity loads, continuous spans, standing seam roofs, and insulated roof and wall systems in the future. System flexural capacity is calculated with the usual DSM approach – global buckling, local global buckling interaction, and distortional buckling strengths are determined with a finite strip eigen-buckling analysis including a rotational spring …


An Explicit, Dynamic Finite Element Model For The Local Failure Of Cold-Formed Trapezoidal Sheeting, Hèrm Hofmeyer Aug 2012

An Explicit, Dynamic Finite Element Model For The Local Failure Of Cold-Formed Trapezoidal Sheeting, Hèrm Hofmeyer

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

Trapezoidal sheeting, made of cold-formed, thin-walled steel, is widely used for the construction of cladding and roofs. At an interior support, the sheeting is subject to bending moments and a concentrated load, which leads to possible failure followed by two post-failure modes: the yield-arc and yield-eye modes. Until recently, it was not fully understood why a specific post-failure mode occurs and it was suggested that mode-jumping of the compressed sheeting flange may influence the mode occurring. This paper presents new research, in which both the compressed flange in isolation and the sheeting are modeled by using an explicit, dynamic finite …


Design Of Perforated Industrial Storage Rack Columns For Distortional Buckling, Teoman Peköz, Güven Kıymaz, Miquel Casafont, Maria Magdalena Pastor, Jordi Bonada Aug 2012

Design Of Perforated Industrial Storage Rack Columns For Distortional Buckling, Teoman Peköz, Güven Kıymaz, Miquel Casafont, Maria Magdalena Pastor, Jordi Bonada

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

The results of an on-going research program to develop a design procedure for perforated industrial storage rack columns are presented. The design procedure includes the effects of distortional buckling. The types of columns studied include those commonly used in Europe and some that are used in the US. The design procedure is being developed based on finite element studies verified by physical testing. The design procedure involves the use of the current US rack column design approach with an extension to distortional buckling with Finite Strip Method (FSM) solutions and Direct Strength Method (DSM) approaches. The approach originally developed for …


Advanced Design Optimization Of Cold-Formed Steel Portal Frame Buildings, Duoc T. Phan, James B. P. Lim, Tiku T. Tanyimboh, Wei Sha Aug 2012

Advanced Design Optimization Of Cold-Formed Steel Portal Frame Buildings, Duoc T. Phan, James B. P. Lim, Tiku T. Tanyimboh, Wei Sha

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

The design optimization of cold-formed steel portal frame buildings is considered in this paper. The objective function is based on the cost of the members for the main frame and secondary members (i.e., purlins, girts, and cladding for walls and roofs) per unit area on the plan of the building. A realcoded niching genetic algorithm is used to minimize the cost of the frame and secondary members that are designed on the basis of ultimate limit state. It is shown that the proposed algorithm shows effective and robust capacity in generating the optimal solution, owing to the population’s diversity being …


Using Generalized Beam Theory (Gbt) To Assess The Buckling Behavior Of Cold-Formed Steel Structural Systems, Cilmar Basaglia, Dinar Camotim Aug 2012

Using Generalized Beam Theory (Gbt) To Assess The Buckling Behavior Of Cold-Formed Steel Structural Systems, Cilmar Basaglia, Dinar Camotim

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

This paper deals with the application of beam finite element models based on Generalized Beam Theory (GBT) to analyze the buckling behavior of three cold-formed steel structural systems, namely (i) beams belonging to storage rack systems, (ii) portal frames built from rectangular hollow section (RHS) profiles and (iii) roof-supporting trusses, exhibiting different support conditions and subjected to various loadings. In particular, taking advantage of the GBT unique and structurally clarifying modal features, it is possible to assess how different geometries and/or bracing arrangements affect (improve) the local, distortional and/or global buckling behavior of the above structural systems. The accuracy of …


Investigation Of Behavior Of Cold-Formed Steel Sheeting Systems In Fire Using Finite Element Modeling, W. Lu, P. Mäkeläinen, J. Outinen, Z. Ma Aug 2012

Investigation Of Behavior Of Cold-Formed Steel Sheeting Systems In Fire Using Finite Element Modeling, W. Lu, P. Mäkeläinen, J. Outinen, Z. Ma

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

A 3D Finite Element (FE) model of steel sheeting, which includes the screw connector and support plate, is created to investigate the behavior of both steel sheeting and connections at elevated temperatures. The created model considers the material nonlinearity, large deformation and contact behavior. The material damage model for sheeting steel is defined so that the FE model is analyzed through the elastic and plastic ranges up to failure. The FE model is used to predict the ultimate resistance and deformation. The current FE model captures the main behavior of steel roof systems well up to around 20 minutes according …


Active Shear Planes In Block Shear Failure Of Bolted Connections, Drew D. A. Clements, Lip H. Teh Aug 2012

Active Shear Planes In Block Shear Failure Of Bolted Connections, Drew D. A. Clements, Lip H. Teh

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

In the AISI Specification for the Design of Cold-formed Steel Structural Members 2007, there are two types of shear planes used to determine the resistance of a bolted connection to block shear failure. When the block shear failure occurs by shear yielding and tensile rupture, the shear failure plane is taken to be the gross shear plane. Conversely, when the block shear failure is deemed to occur by simultaneous shear and tensile ruptures, the shear failure plane is assumed to be the net shear plane. Such an approach is not logical since the shear failure planes should be unique irrespective …


In-Plane Shear Lag Of Bolted Connections, Lip H. Teh, Benoit P. Gilbert Aug 2012

In-Plane Shear Lag Of Bolted Connections, Lip H. Teh, Benoit P. Gilbert

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

This paper points out that the shear lag factors embedded in the design equations specified in the North American, European and Australasian cold-formed steel structures codes for determining the net section tension capacity of bolted connections in flat steel sheets either yield “anomalous” results or become irrelevant when they exceed unity. The anomaly is demonstrated through laboratory tests and is explained using simple calculus. A proper mathematical expression for the in-plane shear lag factor, which does not suffer from the anomaly of the code equations and never implies shear lag factors greater than unity for any configuration, is presented and …


Prediction Of Joint Temperatures In Shot-Nailed Cold-Formed Steel Sheeting With Finite Element Modelling, Z. Ma, W. Lu, P. Mäkeläinen, J. Outinen Aug 2012

Prediction Of Joint Temperatures In Shot-Nailed Cold-Formed Steel Sheeting With Finite Element Modelling, Z. Ma, W. Lu, P. Mäkeläinen, J. Outinen

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

This paper investigates the 3D temperature fields of the shot-nailed steel roof sheeting joints in fire using commercial Finite Element (FE) software ABAQUS when the connected members and connections are protected by either intumescent paint or rockwool panels. Numerical models and parameters used in the models are briefly introduced. When expanded in fire, both thickness and thermal conductivity are varied with increased temperatures. The simplified representation of intumescent paint is described. Parametric analyses are performed in order to investigate the sensitivity of the parameters of thermal contacts. When the joints are protected with rockwool panels, the approximate cavity radiation method …


Modal Identification Of Cold-Formed Steel Members In Shell Finite Element Models, Z. Li, S. Ádány, B. W. Schafer Aug 2012

Modal Identification Of Cold-Formed Steel Members In Shell Finite Element Models, Z. Li, S. Ádány, B. W. Schafer

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

This paper illustrates new capabilities for modal identification of shell Finite Element Method (FEM) models of thin-walled cold-formed steel members. The separation of general deformations into fundamental buckling deformation classes: local, distortional, global, shear, and transverse extension, originated with the constrained Finite Strip Method (cFSM) and is extended here to shell element based FEM analysis. The cFSM base vectors for general end boundary conditions, previously developed by the authors, provide a series of general base functions capable of separating displacements into classes. FEM displacements are identified by minimizing error between the actual FEM displacements and those predicted by the cFSM …


Analytical Model For Cold-Formed Steel Framed Shear Wall With Steel Sheet Sheathing, Noritsugu Yanagi, Cheng Yu Aug 2012

Analytical Model For Cold-Formed Steel Framed Shear Wall With Steel Sheet Sheathing, Noritsugu Yanagi, Cheng Yu

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

The cold-formed steel framed shear wall sheathed with steel sheet sheathing (CFS-SSSW) is a code approved lateral force resisting system for light framed construction. The AISI Steel Framing Standards – Lateral Design (AISI S213-07) provides design provisions for CFS-SSSW. The development of the nominal strength of CFS-SSSW in AISI S213 was based on full-scale experiments which were subjected to limitations in both wall configurations and material properties. This paper presents an analytical model – the Effective Strip Model developed for predicting the nominal strength of CFS-SSSWs. The proposed analytical model and supporting design equations are further verified by experimental results. …


Initial Study And Verification Of A Distributed Fiber Optic Corrosion Monitoring System For Transportation Structures, Hai Xiao, Genda Chen, Zhan Gao, Ying Huang, Fujian Tang Jul 2012

Initial Study And Verification Of A Distributed Fiber Optic Corrosion Monitoring System For Transportation Structures, Hai Xiao, Genda Chen, Zhan Gao, Ying Huang, Fujian Tang

Electrical and Computer Engineering Faculty Research & Creative Works

For this study, a novel optical fiber sensing system was developed and tested for the monitoring of corrosion in transportation systems. The optical fiber sensing system consists of a reference long period fiber gratings (LPFG) sensor for corrosive environmental monitoring and a LPFG sensor coated with a thin film of nano iron and silica particles for steel corrosion monitoring. The environmental effects (such as pH and temperature) are compensated by the use of the reference LPFG sensor. The sensor design, simulation, and experimental validation were performed in this study to investigate the feasibility of the proposed sensing system for corrosion …


Behavior Of Full-Scale Rc T-Beams Strengthened In Shear With Externally Bonded Frp Sheets, Abdeldjelil Belarbi, Sang Wook Bae, Antonio Brancaccio Jul 2012

Behavior Of Full-Scale Rc T-Beams Strengthened In Shear With Externally Bonded Frp Sheets, Abdeldjelil Belarbi, Sang Wook Bae, Antonio Brancaccio

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recently many research studies have investigated the shear behavior of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) composites. However, most were conducted on small-scale specimens. Thus, analytical models and design equations developed from those studies may not predict the actual behavior of large-scale RC beams strengthened with FRPs. in this study, an experimental study was performed on this topic using full-scale RC T-beams in order to understand the behavior of full-scale bridge beams strengthened in shear with FRP. the main parameters investigated in this study were the transverse steel reinforcement ratio and the effect of mechanical anchorage systems. …


Concrete Surface With Nano-Particle Additives For Improved Wearing Resistance To Increase Truck Traffic, Genda Chen, Dongming Yan, Chenglin Wu, Zhibin Lin, Nicholas Leventis, Shruti Mahadik-Khanolkar Jul 2012

Concrete Surface With Nano-Particle Additives For Improved Wearing Resistance To Increase Truck Traffic, Genda Chen, Dongming Yan, Chenglin Wu, Zhibin Lin, Nicholas Leventis, Shruti Mahadik-Khanolkar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study focused on the use of nanotechnology in concrete to improve the wearing resistance of concrete. The nano materials used were polymer cross-linked aerogels, carbon nanotubes, and nano-SiO2, nano-CaCO3, and nano-Al2O3 particles. As an indirect measurement of the concrete wearing resistance, the tensile and compressive properties and the permeability of concrete were evaluated for various mix designs. The optimal amount of nano material additives were determined following the American Society of Testing Methods (ASTM) standard test methodologies. The test results from the materials were compared for their mechanical behaviors. This type of …


Multinomial Logistic Regression Model For Single-Vehicle And Multivehicle Collisions On Urban U.S. Highways In Arkansas, Ghulam Bham, Bhanu S. Javvadi, Uday R.R. Manepalli Jun 2012

Multinomial Logistic Regression Model For Single-Vehicle And Multivehicle Collisions On Urban U.S. Highways In Arkansas, Ghulam Bham, Bhanu S. Javvadi, Uday R.R. Manepalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Multivariate analysis can be used to identify the effects of several factors on the causes of a crash compared with univariate analysis. This paper uses a multivariate-analysis technique, the multinomial logistic regression (MLR) model, to examine the differences in crash-contributing factors for six collision types for both divided- and undivided-highway nonjunctions, given that a crash has occurred. Multinomial logistic regression was used to investigate (1) single-vehicle and (2) multivehicle collisions, which included (1) angular, (2) head-on, (3) rear-end, (4) sideswipe-same-direction, and (5) sideswipe-opposite-direction collisions. the risks associated with different collision types were found to be significantly influenced by various vehicle …


Development And Testing Of Chemically-Based Self-Consolidating Concrete, Mahdi Arezoumandi, Mark Ezzell, Jeffery S. Volz Jun 2012

Development And Testing Of Chemically-Based Self-Consolidating Concrete, Mahdi Arezoumandi, Mark Ezzell, Jeffery S. Volz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-consolidating concrete (SCC) has the potential to significantly reduce costs associated with concrete construction. SCC is a highly flowable, Non segregating concrete that has a variety of advantages over conventional concrete (CC). However, SCC is not without its problems, which can include increased creep and shrinkage, as well as decreased bond and shear strength. the goal of this research project was to evaluate the creep, shrinkage, and shear behavior of a chemically Based SCC mix. One of the benefits of a chemically Based approach is the potential to eliminate the negative side effects of many SCC mixes. the investigation included …


High-Volume Fly Ash Concrete For Sustainable Construction, Jeffery S. Volz Jun 2012

High-Volume Fly Ash Concrete For Sustainable Construction, Jeffery S. Volz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

With worldwide production of fly ash approaching 800 million tons annually, increasing the amount of fly ash used in concrete will remove more material from the solid waste stream and reduce the amount ending up in landfills. However, most specifications limit the amount of cement replacement with fly ash to less than 25 or 30%. Concrete with fly ash replacement levels of at least 50% - referred to as high-volume fly ash (HVFA) concrete - offers a potential green solution. the following study investigated the structural performance of HVFA concrete compared to conventional Portland-cement concrete. Specifically, the research examined both …


An Inverted Teaching Model For A Mechanics Of Materials Course, Jeffery S. Thomas, Timothy A. Philpot Jun 2012

An Inverted Teaching Model For A Mechanics Of Materials Course, Jeffery S. Thomas, Timothy A. Philpot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Instructors at Missouri University of Science and Technology have been offering certain sections of a mechanics of materials course in an inverted format for the past two years. In this format, students learn the concepts outside of class, using a textbook, animations and videos developed by the authors, and work on homework either individually or in groups during the optional class time. Students take eight multiple-choice exams and a final exam that is common to both the inverted sections and the more traditional lecture-based sections. Homework in the inverted sections is assigned but not graded. The in-class exams are given …


Sensors For Integrated Monitoring And Mitigation Of Scour, Genda Chen, David Pommerenke, Zhi Zhou, Ying Huang May 2012

Sensors For Integrated Monitoring And Mitigation Of Scour, Genda Chen, David Pommerenke, Zhi Zhou, Ying Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Systems and methods for detecting scour. Some embodiments provide systems which include a sensor and a signal generator with a combined density equal to or greater than that of water. Optionally, the sensor can be a magnet, magnetic resonator, or accelerometer. In some embodiments, the sensor is adapted to be placed in regions potentially subject to scour and to sense a scour-related condition. The signal generator generates a wireless signal conveying data regarding the as-sensed scour-related. In some embodiments the sensor is the signal generator while a receiver of the wireless signal can include an antenna, a magnetometer, or an …


Monotonic Behavior Of Mississippi River Valley Silt In Triaxial Compression, Shuying Wang, Ronaldo Luna Apr 2012

Monotonic Behavior Of Mississippi River Valley Silt In Triaxial Compression, Shuying Wang, Ronaldo Luna

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The static behavior of Mississippi River Valley silt was characterized using triaxial compression testing. Silt specimens, especially over consolidated ones, showed dilation behavior. There was no unique critical state among specimens with different over consolidation ratios (OCRs). with OCRs of 1, 2, and 8, the specimens exhibited normal behavior and dilated more as effective consolidation pressure dropped. However, for an OCR of 4, the specimens showed opposite behavior and dilated more as effective consolidation pressure rose. the friction angle of the silt was computed on the basis of several failure criteria, and the limiting strain was found to be the …