Civil Engineering Faculty Research and Publications
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Item Open Access A Wire Indent Profiling System for the Assessment of Bond and Splitting Propensity of Prestressing Wires Used in Pretensioned Concrete Railroad Ties(Rural Railroad Safety Center, Kansas State University., 2021-04-01) Beck, B. Terry; Robertson, Aaron A.; Peterman, Robert J.; Riding, Kyle A.The focus of this research was the creation of an automatic non-contact laser-based indent profiling system for the purpose of rapidly assessing geometrical characteristics of indented wires used in the manufacture of pretensioned concrete railroad ties. The process of measuring indent geometrical characteristics by traditional means is a time-consuming process which severely limits the frequency of testing and prevents statistically relevant sample sizes. In parallel with concrete prism transfer length and splitting propensity testing conducted in conjunction with this project, this system was used to identify which indent characteristics were directly related to both bond and splitting propensity in pretensioned concrete ties. This report details the automation of this indent profiling system and the results obtained for many different indented wires that were currently or historically used to manufacture pretensioned concrete railroad ties.Item Open Access High Resolution 3D Optical Scanning of Crossties to Assess Cross-Sectional Parameters and the Effects of Long-Term Abrasion and Wear(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Beck, B. Terry; Robertson, Aaron A.; Peterman, Robert J.; Riding, Kyle A.This report documents measurement of the 3D geometrical properties associated with prestressed concrete railroad ties that have been subject to long-term in-track loading. A commercially-available 3D laser-based optical scanning system was used to scan the surface of sampled in-service crossties to a spatial resolution of about 1-mm, resulting in a 3D solid body CAD model of each scanned tie. A high-speed algorithm was developed to process the detailed cross-section geometrical parameters to an axial resolution of 0.5 inches, achieving an overall processing time of only a few minutes. The agreement between the ideal CAD model cross-section parameters and the measured (scanned) parameters was found to be excellent. Measured crosstie cross-sectional parameters used in support of on-going FRA project work included cross-sectional area, area moment of inertia, neutral axis position, eccentricity, and shape factor.Item Open Access Developing a Prism Qualification Test to Ensure Adequate Splitting Resistance in Pretensioned Concrete Railroad Ties(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Savic, Adrijana; Peterman, Robert J.; Beck, B. Terry; Riding, Kyle A.This report presents the results from research that evaluated the effect of wire indentation type, edge distance, and the strength of concrete at de-tensioning on longitudinal splitting in pretensioned concrete railroad ties. Four-wire pretensioned concrete prisms were cast with varying reinforcement types and edge distances and the resulting splitting crack lengths were carefully measured. Results showed that concrete edge distance was the most significant factor affecting longitudinal splitting cracks, with reinforcement indentation type also playing a key role. This work resulted in the successful development of a qualification test to ensure adequate splitting resistance in pre-tensioned concrete railroad ties. This test was formally adopted as section 4.2.4 in Chapter 30 of the 2021 AREMA Manual for Railway Engineering.Item Open Access Effect of Concrete Composition on Splitting Cracks in Prestressed Concrete Railroad Ties: Application of Fracture Mechanics(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Dastgerdi, Aref S.; Peterman, Robert J.; Beck, B. Terry; Riding, Kyle A.The effect of concrete composition on end-splitting cracks in pretensioned concrete members was investigated. Specific parameters included the effect of aggregate shape and content, water-to-cementitious (w/cm) ratio, fly ash, paste and air void content. For each mixture evaluated, prisms were load tested in three-point bending at 4000, 6000 and 8000 psi to determine the effect of concrete compressive strength on crack growth potential. Corresponding splitting tensile tests were also conducted on samples at each compressive strength for all mixtures. Results show that increasing angularity, aggregate size distribution, and decreasing w/cm ratio improve fracture toughness by as much as 28% whereas changing other parameters had little effect. All improving factors were seen to be most effective at low strengths. A statistical model predicting fracture toughness was developed, and the results correlated well with observed cracking in pretensioned concrete members.Item Open Access Use of 3D Non-Contact Profilometry to Quantify Indent Characteristics of Prestressing Wires Used in Pretensioned Concrete Railroad Ties(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Haynes, Mark; Wu, Chih-Hang; Beck, B. Terry; Peterman, Robert J.The objective of this research was to investigate possible correlation between prestressing wire indent geometry and the performance of pretensioned concrete members fabricated with these same reinforcements. Thirteen (13) commercially available and twelve (12) custom-made reinforcement wires were evaluated. A new non-contact indent profiling system was developed to collect detailed surface profiles of the prestressing steel. New geometrical feature measurements and processing algorithms were developed to provide detailed measurement of prestressing steel according to the dimensioning and tolerancing guidelines of ASME Y14.5-2009. These geometrical features were found to have significant correlation with the transfer length and fracture propensity of concrete crossties. Models were created to predict the transfer length of concrete crossties based on the extracted indent characteristics.Item Open Access Automated Optical Surface Strain Measurement System to Determine the Transfer Length in Pretensioned Concrete Railroad Ties(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Beck, B. Terry; Peterman, Robert J.; Wu, Chih-HangThis report documents the advances that have been made to determine the transfer length of pretensioned concrete railroad ties using non-contact surface displacement measurements by digital image correlation. The work has culminated with two fully-functional devices that address specific needs of the industry. The first device utilizes a multi-camera method for measuring the surface strain profile on a railroad tie and determining the associated transfer length to within +/- 1.5 in. with as few as 5 independent measurements of surface strain. The work represents a practical step towards the continuous monitoring of in-plant prestressed railroad tie production, using transfer length as a quality control parameter. The second device is capable of making measurements of strain in a real-time continuously scanning/traversing (CST) manner over the entire distance range of interest on the tie associated with transfer-length development. It was shown to be capable of a strain measurement resolution of nominally about ± 20 microstrain, at traversing speeds of up to several inches per second.Item Open Access Development of Un-Tensioned Pullout Tests to Determine the Bond Quality of Prestressing Reinforcements Used in Pretensioned Concrete Railroad Ties(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Arnold, Matthew L.; Peterman, Robert J.; Beck, B. Terry; Wu, Chih-HangAn experimental program was conducted at Kansas State University (KSU) to evaluate the bond characteristics of prestressing wires and strands used in the manufacture of pretensioned concrete railroad ties. Un-tensioned pullout tests were conducted using both concrete and mortar mediums. The effect of prestressing steel surface condition on bond was evaluated by testing the bond in both the as-received and cleaned condition. A pullout test was developed (and subsequently adopted as ASTM A1096) that can be used to determine the bond quality of prestressing wires that are are in pretensioned concrete members. The pullout test specimens consist of a 4 in. outer-diameter tube with a total length of 8 in. and a steel plate welded to the tube bottom. An un-tensioned wire is held concentrically in the tube while a sand-cement mortar mixture is placed and allowed to cure. Specimens are tested when compressive strength of the mortar is between 4500 and 5000 psi. Pullout test results had excellent correlation with transfer lengths of similar wires when used to manufacture pretensioned concrete railroad ties.Item Open Access Effect of Concrete Properties and Prestressing Steel Reinforcement Type on the Development Length in Pretensioned Concrete Railroad ties(Rural Railroad Safety Center, Kansas State University., 2021-03-03) Momeni, Amir F.; Peterman, Robert J.; Beck, B. Terry; Wu, Chih-HangA study was conducted to determine the effect of different concrete properties and prestressing steel reinforcement type on the development length and flexural capacity of prestressed concrete railroad ties. Thirteen different 5.32-mm-diameter prestressing wires and six different strands (four 7-wire strands and two 3-wire strands) were used to fabricate 4-tendon pretensioned prisms with a square cross section. A consistent concrete mixture utilizing Type III cement and a water-to-cementitious ratio of 0.32 was used for all prisms. The prisms were detensioned at concrete compressive strengths of 3500 psi, 4500 psi, and 6000 psi. Load tests revealed that there is a large difference in the development length for different wire/strand types as well as with different concrete release strengths. Additionally, cyclic load tests revealed that there is also a significant difference in the bond performance of these reinforcement types under repeated loadings.Item Open Access Using Tensioned Pullout Tests to Determine the Bond-Slip Relationship and Splitting-Propensity of Reinforcements Used in Pretensioned Concrete Railroad Ties(Rural Railroad Safety Center, Kansas State University., 2021-03-02) Holste, Joseph R.; Peterman, Robert J.; Beck, B. Terry; Wu, Chih-HangA study was conducted to evaluate the bond and splitting propensity characteristics of 12 different 5.32-mm-diameter prestressing wires used in the production of prestressed concrete railroad ties. Establishment of the bond-slip relationship of these wires at both transfer of prestress (transfer bond) and under flexural loading (flexural bond) was necessary to enable the accurate modeling of these ties using finite elements. Transfer bond and flexural bond of various indent patterns were tested using tensioned pullout tests. Specimens of various sizes with single or multiple wires were tested to determine the effects of cover and wire quantity on bond. Results from the testing program showed 1) the tensioned pullout tests could be used to predict the transfer length of prisms made with the same reinforcement, 2) the indent geometry depth and side-wall angle are good indicators of the likelihood of specimen splitting cracks, and 3) the importance of adequate concrete cover to eliminate potential splitting cracks.Item Open Access Evaluation of the Remaining Prestress Force and Center Negative Capacity of Ties Removed from Track after 25 Years(Rural Railroad Safety Center, Kansas State University., 2021-03-01) Scott, James D.; Peterman, Robert J.; Beck, B. Terry; Riding, Kyle A.A study was conducted to determine the amount of internal prestress force remaining in prestressed concrete railroad tie designs that have withstood a lifetime of service without problems. Twelve (12) different tie designs that had performed well in track for over 25 years with no signs of longitudinal splitting were evaluated. Four different experimental test methods were used to determine the remaining prestress force in these existing ties. These included the flexural crack reopening method, the newly developed direct tension method, the strain gage method, and measurement of the length change of wires extracted from the ties. Test results indicate that the direct tension test was the most accurate of the four methods, and that existing ties tended to have prestressing forces in the range of 82-93 kips.Item Open Access A Comprehensive Study of Prestressing Steel and Concrete Variables Affecting Transfer Length in Pre-Tensioned Concrete Crossties(Rural Railroad Safety Center, Kansas State University., 2021-02) Bodapati, Naga N.B.; Peterman, Robert J.; Beck, B. Terry; Wu, Chih-Hang; bobA comprehensive study was conducted to determine the variation of transfer length in pretensioned prestressed concrete railroad ties with varying prestressing steel types and concrete parameters. The in-depth evaluation included eighteen different prestressing reinforcement types that are employed in concrete railroad ties worldwide. The study consisted of two phases: Lab- Phase and Plant-Phase. Throughout the study, transfer lengths were determined from surface strain measurements on pre-tensioned concrete members. During the Lab-Phase, pre-tensioned concrete prisms were fabricated to replicate plant manufactured crossties. A special jacking arrangement was employed to ensure that each of the reinforcements was tensioned to the same force. Later, during the Plant-Phase, pre-tensioned concrete railroad ties were fabricated at a concrete crosstie manufacturing plant using the same reinforcements. In addition, a long-term study was conducted on plant-manufactured crossties to determine the variation of transfer length due to in-track loading.Item Open Access Investigating the Role of Social Responsibility on Veteran Student RetentionKulesza, Stacey E.; Liang, Grace L.; Fitzsimmons, Eric J.; Zacharakis, Jeff; Hood, Jeffrey C.; hoodjcDespite considerable gains made towards increasing students’ interest in STEM education, one specific population, Veterans in engineering, suffers from disproportionally high attrition. Social responsibility is a motivating factor for becoming an engineer and has been identified as a successful intervention strategy to improve retention of first-year engineering students. Social responsibility is also a core value instilled by all branches of the U.S. military while actively serving. Therefore, the objective of this research study was to examine Veterans’ perceptions of social responsibility related to engineering. For this study, a survey instrument was designed, piloted, revised, and launched for instrument validation and exploratory examination of the relationship between social responsibility and Veteran students’ core beliefs. Results of this study showed that both Veteran and first-year non-Veteran engineering students strongly value the tenants of social responsibility. The results of this study indicate the potential for curriculum and policy changes to increase Veteran retention in engineering programs.Item Open Access Analysis of vadose zone inhomogeneity toward distinguishing recharge rates: Solving the nonlinear interface problem with Newton method(2016-11-01) Steward, David R.; steward; Steward, David R.Recharge from surface to groundwater is an important component of the hydrological cycle, yet its rate is difficult to quantify. Percolation through two-dimensional circular inhomogeneities in the vadose zone is studied where one soil type is embedded within a uniform background, and nonlinear interface conditions in the quasilinear formulation are solved using Newton's method with the Analytic Element Method. This numerical laboratory identifies detectable variations in pathline and pressure head distributions that manifest due to a shift in recharge rate through in a heterogeneous media. Pathlines either diverge about or converge through coarser and finer grained materials with inverse patterns forming across lower and upper elevations; however, pathline geometry is not significantly altered by recharge. Analysis of pressure head in lower regions near groundwater identifies a new phenomenon: its distribution is not significantly impacted by an inhomogeneity soil type, nor by its placement nor by recharge rate. Another revelation is that pressure head for coarser grained inhomogeneities in upper regions is completely controlled by geometry and conductivity contrasts; a shift in recharge generates a difference Dp that becomes an additive constant with the same value throughout this region. In contrast, shifts in recharge for finer grained inhomogeneities reveal patterns with abrupt variations across their interfaces. Consequently, measurements aimed at detecting shifts in recharge in a heterogeneous vadose zone by deciphering the corresponding patterns of change in pressure head should focus on finer grained inclusions well above a groundwater table.Item Open Access Partial Confinement Utilization for Rectangular Concrete Columns Subjected to Biaxial Bending and Axial Compression(2017-02-10) Abd El Fattah, A. M.; Rasheed, Hayder A.; Al-Rahmani, A. H.; hayder; Rasheed, HayderThe prediction of the actual ultimate capacity of confined concrete columns requires partial confinement utilization under eccentric loading. This is attributed to the reduction in compression zone compared to columns under pure axial compression. Modern codes and standards are introducing the need to perform extreme event analysis under static loads. There has been a number of studies that focused on the analysis and testing of concentric columns. On the other hand, the augmentation of compressive strength due to partial confinement has not been treated before. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength of concrete. Accordingly, the ultimate eccentric confined strength is gradually reduced from the fully confined value f(cc) (at zero eccentricity) to the unconfined value f(c)(1) (at infinite eccentricity) as a function of the ratio of compression area to total area of each eccentricity. This approach is used to implement an adaptive Mander model for analyzing eccentrically loaded columns. Generalization of the 3D moment of area approach is implemented based on proportional loading, fiber model and the secant stiffness approach, in an incremental-iterative numerical procedure to achieve the equilibrium path of P-epsilon and M-phi response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns confined with conventional lateral steel. This analysis is validated against experimental data found in the literature showing good correlation to the partial confinement model while rendering the full confinement treatment unsafe.Item Open Access Archaea and Bacteria Acclimate to High Total Ammonia in a Methanogenic Reactor Treating Swine Waste(2016-09-20) Esquivel-Elizondo, S.; Parameswaran, P.; Delgado, A. G.; Maldonado, J.; Rittmann, B. E.; Krajmalnik-Brown, R.; prathapp; Parameswaran, PrathapInhibition by ammonium at concentrations above 1000mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H-2 accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH3 -N) from 890 +/- 295 to 2040 +/- 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophic Methanoculleus (36.4%) and Methanobrevibacter (11.6%), along with acetoclastic Methanosaeta (29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers (Clostridium, Coprococcus, and Sphaerochaeta) and syntrophic fatty-acid Bacteria (Syntrophomonas, Clostridium, Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than similar to 1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of similar to 2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis.Item Open Access Impact of Ammonium on Syntrophic Organohalide-Respiring and Fermenting Microbial Communities(2016-04-20) Delgado, A. G.; Fajardo-Williams, D.; Kegerreis, K. L.; Parameswaran, Prathap; Krajmalnik-Brown, R.; prathapp; Parameswaran, PrathapSyntrophic interactions between organohalide-respiring and fermentative microorganisms are critical for effective bioremediation of halogenated compounds. This work investigated the effect of ammonium concentration (up to 4 g liter(-1) NH4+-N) on trichloroethene-reducing Dehalococcoides mccartyi and Geobacteraceae in microbial communities fed lactate and methanol. We found that production of ethene by D. mccartyi occurred in mineral medium containing <= 2 g liter(-1) NH4+-N and in landfill leachate. For the partial reduction of trichloroethene (TCE) to cis-dichloroethene (cis-DCE) at >= 1 g liter(-1) NH4+-N, organohalide-respiring dynamics shifted from D. mccartyi and Geobacteraceae to mainly D. mccartyi. An increasing concentration of ammonium was coupled to lower metabolic rates, longer lag times, and lower gene abundances for all microbial processes studied. The methanol fermentation pathway to acetate and H-2 was conserved, regardless of the ammonium concentration provided. However, lactate fermentation shifted from propionic to acetogenic at concentrations of >= 2 g liter(-1) NH4+-N. Our study findings strongly support a tolerance of D. mccartyi to high ammonium concentrations, highlighting the feasibility of organohalide respiration in ammonium-contaminated subsurface environments. IMPORTANCE Contamination with ammonium and chlorinated solvents has been reported in numerous subsurface environments, and these chemicals bring significant challenges for in situ bioremediation. Dehalococcoides mccartyi is able to reduce the chlorinated solvent trichloroethene to the nontoxic end product ethene. Fermentative bacteria are of central importance for organohalide respiration and bioremediation to provide D. mccartyi with H2, their electron donor, acetate, their carbon source, and other micronutrients. In this study, we found that high concentrations of ammonium negatively correlated with rates of trichloroethene reductive dehalogenation and fermentation. However, detoxification of trichloroethene to nontoxic ethene occurred even at ammonium concentrations typical of those found in animal waste (up to >= 2 g liter(-1) NH4+-N). To date, hundreds of subsurface environments have been bioremediated through the unique metabolic capability of D. mccartyi. These findings extend our knowledge of D. mccartyi and provide insight for bioremediation of sites contaminated with chlorinated solvents and ammonium.Item Open Access Thermal analysis of GFRP-reinforced continuous concrete decks subjected to top fire(2017-09-11) Hawileh, Rami A.; Rasheed, Hayder A.; hayder; Rasheed, Hayder A.This paper presents a numerical study that investigates the behavior of continuous concrete decks doubly reinforced with top and bottom glass fiber reinforced polymer (GFRP) bars subjected to top surface fire. A finite element (FE) model is developed and a detailed transient thermal analysis is performed on a continuous concrete bridge deck under the effect of various fire curves. A parametric study is performed to examine the top cover thickness and the critical fire exposure curve needed to fully degrade the top GFRP bars while achieving certain fire ratings for the deck considered. Accordingly, design tables are prepared for each fire curve to guide the engineer to properly size the top concrete cover and maintain the temperature in the GFRP bars below critical design values in order to control the full top GFRP degradation. It is notable to indicate that degradation of top GFRP bars do not pose a collapse hazard but rather a serviceability concern since cracks in the negative moment region widen resulting in simply supported spans.Item Open Access Flexural behavior of reinforced concrete beams strengthened with externally bonded Aluminum Alloy plates(2017-09-15) Rasheed, Hayder A.; Abdalla, Jamal; Hawileh, Rami; Al-Tamimi, Adil K.; hayder; Rasheed, Hayder A.The objective of this experimental investigation is to study the viability and effectiveness of using Aluminum Alloy (AA) plates as externally bonded flexural reinforcement for reinforced concrete (RC) beams. Ten RC beams were prepared and nine of them were strengthened with externally bonded 2 mm and 3 mm thick AA plates with different mechanical properties. Four strengthened beams had no end wraps or anchorages. Single-layer and double-layer U-wrap CFRP sheets were used in the transverse direction as end anchorages for four strengthened beams and one beam had three double anchorages (two at the ends and one at mid-span). The beams were tested under monotonic load until failure. The goal is to study the effect of using AA plates as externally bonded flexural strengthening material and to explore the effect of end anchorages on the flexural strength and ductility of these beams. The increase in strength over the control unstrengthened specimen ranged from 13% to 40% while the ductility significantly surpassed that of beams strengthened with CFRP sheets. It is observed that the use of end anchorages enhanced the ductility but not the strength of the tested beams. It is also observed that beams without end anchorage failed predominantly in flexure with full de-bonding while beams with end anchorage failed by localized de-bonding and flexure. Furthermore, the performance of the tested beams was compared with numerical predictions by a computer program developed in this study. The results of the numerical models were in close agreement with the measured experimental data. It was concluded that AA plates could be used as an external strengthening material to enhance both the strength and ductility of RC beams in flexure.Item Open Access Buckling of Nonprismatic Column on Varying Elastic Foundation with Arbitrary Boundary Conditions(2017-04-27) Ghadban, Ahmad A.; Al-Rahmani, Ahmed H.; Rasheed, Hayder A.; Albahttiti, Mohammed T.; hayder; bahttiti; Ghadban, Ahmad A.; Rasheed, Hayder A.; Albahttiti, Mohammed T.Buckling of nonprismatic single columns with arbitrary boundary conditions resting on a nonuniform elastic foundation may be considered as the most generalized treatment of the subject. The buckling differential equation for such columns is extremely difficult to solve analytically. Thus, the authors propose a numerical approach by discretizing the column into a finite number of segments. Each segment has constants (modulus of elasticity), (moment of inertia), and (subgrade stiffness). Next, an exact analytical solution is derived for each prismatic segment resting on uniform elastic foundation. These segments are then assembled in a matrix from which the critical buckling load is obtained. The derived formulation accounts for different end boundary conditions. Validation is performed by benchmarking the present results against analytical solutions found in the literature, showing excellent agreement. After validation, more examples are solved to illustrate the power and flexibility of the proposed method. Overall, the proposed method provides reasonable results, and the examples solved demonstrate the versatility of the developed approach and some of its many possible applications.Item Open Access The engineering classroom is still relevant(2016-06-26) Fitzsimmons, E. J.; Tucker-Kulesza, S. E.; Li, Xiongya; Jeter, W.; Fallin, Jana R.; fitzsimmons; sekulesza; jfallin; Fitzsimmons, Eric J.; Kulesza, Stacey; Fallin, Jana; Li, XiongyaAttrition in engineering is a complex issue with dynamically linked variables related to teaching methods in the classroom, student learning behaviors, and student perceptions of difficult material. Extensive research has been conducted in order to understand common, yet ineffective teaching practices in engineering that result in the loss of numerous future engineers. The objective of this study was to determine student actions necessary to achieve a desired grade in any engineering course, regardless of course delivery method and instructor effectiveness in the classroom. An anonymous survey was disseminated and logistic regression models were developed in order to determine relationships between self-regulated learning behaviors and final grades in seven freshman to senior engineering classes taught by civil engineering faculty. A total of five prediction models were developed for each letter grade, with the failing grade "F" serving as the baseline condition, or null model. The models found three significant variables that affect a student's final grade: regular class attendance, note-taking during class, and if he or she could keep up with the instructor during lecture. These interactive learning behaviors were all identified as critical for success, defining success as receiving an "A" in an engineering course. The combination of students taking notes and attending class showed the highest probability of a student receiving an "A." Results of this study have been summarized into a graphic that the authors show and discuss during the first class with students. This powerful graphic shows students what they can do in classes of all levels of civil engineering to succeed in their ever-changing learning environment. © American Society for Engineering Education, 2016.
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