Doctor of Philosophy / Department of Civil Engineering / Sunanda Dissanayake / Seat belt usage is considered to be one of the most effective ways of improving safety of motor vehicle occupants. Thus, increasing seat belt usage among motorists has become one of the top prioritized goals of many highway safety improvement programs. The main objective of this study was to develop a methodology to estimate potential economic benefits associated with increased seat belt usage by Kansas motorists based on conditions prevailing in the State of Kansas. Seat belt effectiveness in reducing injuries was estimated and those values were then used to estimate economic benefits due to injury reductions. Five methodologies were used to estimate seat belt effectiveness which included multiple logistic regression, double pair comparison method, Cox proportional hazards regression, conditional logistic regression, and risk ratio model using estimating equation approach. Crash data from Kansas Accident Reporting System (KARS) database was used. A procedure was developed to estimate economic benefits due to increased seat belt usage based on State conditions. The highest variation in estimated seat belt effectiveness values using different methods were observed for incapacitating injuries while the lowest variation was observed for possible injuries. For fatal injuries, the estimated seat belt effectiveness values ranged from 50-69% for passenger cars and 57-70% for other passenger vehicles. The range of seat belt effectiveness values for incapacitating injuries was 47-65% for passenger cars and 44-69% for other passenger vehicles. It was also found that the multiple logistic regression method provide relatively narrower confidence intervals for almost all the nonfatal injury categories in both vehicle groups. Based on estimations using logistic regression method, seat belts are 56% effective in preventing fatal injuries in passenger cars and 61% effective in other passenger vehicles. The seat belt effectiveness in reducing incapacitating injuries was found to be 53% in passenger cars and 52% in other passenger vehicles. It was found that if seat belt usage rate in Kansas reaches the national average rate of 81% (2006), the resulted annual economic benefits to the State is estimated to be about $ 191 millions in 2006 dollars or in other words, due to lower seat belt usage currently observed in Kansas compared to national usage level, the annual estimated economic loss is about $ 191 millions. Seat belt effectiveness values are currently not available based on KABCO (K-Fatal, A-Incapacitating, B-Non-incapacitating, C-Possible, and O-No injuries) injury scale. Therefore, this study could serve as an initiative towards establishing a procedure to estimate benefits of seat belt usage based on State highway crash data.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Autoclaved Aerated Concrete (AAC) is a lightweight concrete building material cut into masonry blocks or formed larger planks and panels. Currently it has not seen widespread use in the United States. However, in other parts of the world it use has been used successfully as a building material for over fifty years. AAC is a relatively new (at least to the United States) concrete masonry material that is lightweight, easy to construct, and economical to transport. Its light weight is accomplished through the use of evenly distributed microscopic air bubbles throughout the material; these bubbles result in a lightweight concrete that is composed of a latticework around spherical voids. This report details the history, physical properties, manufacturing process, and structural design of AAC. This report includes an explanation of the 2005 Masonry Standards Joint Committee (MSJC) Code for the design of AAC members subjected to axial compressive loads, bending, combined axial and bending, and shear. An example building design using AAC structural components is provided. This report concludes that AAC has important advantages as a structural building material that deserves further consideration for use in the United States.

Master of Science / Department of Civil Engineering / Hani G. Melhem / The Abilene & Smoky Valley Railroad Association offers train excursions to sightseers wishing to see historic Abilene and natural Kansas scenery. Currently, a diesel powered ALCO locomotive is used to pull the passenger cars. They wish to use a 1919 Baldwin steam locomotive in the future. Part of the excursion includes a slow crossing of the Smoky Hill River over a two-span steel truss bridge. The company approached the Kansas State University Civil Engineering Department with the task of performing a structural check of the bridge. By using the Baldwin locomotive, the bridge is required to support much larger loads than when the diesel engine is used. First, a basic visual inspection and site visit of the bridge was performed. The inspection was not thorough, but was used to familiarize the team with the bridge and its components. Using the inspection and data supplied, a structural analysis was performed using the software, RISA. After completion of the analysis for both loading situations, the resulting stress increases were calculated. Other calculations performed include buckling loads of the compression members, deflections of the bottom chord and stresses in some of the connections. After completion of the analysis and calculations, large increases in member stress were found. For most of the members, the increase of live loads stress was between 80% and 100%. The largest stress found due to the dead and live load, which was under 15 ksi, occurred in the bottom chord for the steam locomotive loading situation. Some truss members experienced stress reversal, but relatively low values were noted. Deflection calculations for the two loading situations yielded similar results to the stress calculations. Again, an increase in deflection between 80% and 100% was found for the joints located on the bottom chord. It is recommended that a more detailed inspection and a more thorough analysis of the connections, supports, piers, and foundations be performed before the heavier locomotive is used.

Master of Science / Department of Civil Engineering / Robert J. Peterman / As of 2005, 23% of the bridges in the Kansas infrastructure are classified as structurally deficient or functionally obsolete according to the ASCE Infrastructure Report Card (ASCE, 2008). One alternative to replacing the entire bridge structure is replacing only the superstructure with lightweight concrete. This option is more economical for city, county, and state governments alike. Replacing the superstructure with lightweight concrete can oftentimes allow the bridge rating to be upgraded to higher load capacities or higher traffic volumes. Furthermore, lightweight concrete can be used initially in a bridge deck to provide reduced weight and a lower modulus of elasticity, therefore lower cracking potential. The Kansas Department of Transportation is interested in the potential benefits of using lightweight aggregate concrete in Kansas bridge decks and prestressed bridge girders. This research project used three types of lightweight aggregate to develop lightweight concrete mixtures for a bridge deck and for prestressed bridge girders. Two of the lightweight aggregates were expanded shale obtained locally from the Buildex Company. One deposit was located in Marquette, Kansas, and the other in New Market, Missouri. The third lightweight aggregate source was expanded slate obtained from the Stalite Company in North Carolina. Aggregate properties including absorption, gradation, and L.A. Abrasion were evaluated. Over 150 lightweight concrete mixtures were created and tested and several mix design variables such as water-to-cement ratio, cement content, and coarse-to-fine aggregate ratio were evaluated. From these results, optimized bridge deck and optimized prestressed concrete mixtures were developed for each type of lightweight aggregate. Special concerns for lightweight aggregate concrete are addressed. These optimized concrete mixtures were then tested for KDOT acceptability standards for the concrete properties of compressive strength, tensile strength, modulus of elasticity, freeze-thaw resistance, permeability, alkali-silica reactivity, drying shrinkage, and autogenous shrinkage. All concrete mixtures performed satisfactorily according to KDOT standards. In addition, an internal curing effect due to the moisture content of the lightweight aggregate was observed during the autogenous shrinkage test.

Master of Science / Department of Civil Engineering / Kyle Riding / Concrete is the most widely used construction material. Concrete strength and durability develop from a series of exothermic reactions involving water called hydration. Long-term durability and performance of concrete is very much dependent on the early hydration behavior of cementitious materials. This study examined the effects of curing temperature and access to moisture on the early age reaction rate of cementitious materials, and methods for quantifying these effects. Apparent activation energy (Ea) relates the effects of temperature on the cement hydration reaction. There are various methods and calculation techniques for estimating Ea that result in greatly varying values. Cement paste and mortar are often used to calculate Ea and used later for concrete. Ea values were calculated using cement mortar and paste by isothermal calorimetry and showed excellent correlation. This validates the use of Ea based on cement paste in modeling concrete behavior. Ea values were also calculated by chemical shrinkage and it showed potential for use in calculating Ea. Cementitious materials need free water to be available for hydration to continue. Curing with either waxy curing compounds or ponded water are common practices. The thickness of distilled water, lime-saturated water, and cement pore water used as a curing method affects the rate of hydration. Water-cementitious material ratio (w/cm) and sample depth affect the performance of water curing, with low w/cm being the most significant. Partial replacement of sand by fine lightweight aggregate also improves the hydration of cementitious material much more than conventional water ponding. Curing compounds showed improvements in cement hydration compared to uncured samples.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Over the past few years, motorcycle fatalities have increased at an alarming rate in the United States. Motorcycle safety issues in Kansas are no different from the national scenario. Accordingly, this study attempted to investigate motorcycle crashes in Kansas to identify critical characteristics and to evaluate the effect of those on motorcycle crash injury outcomes. State-level motorcycle rider fatality rates were investigated while considering various factors including helmet laws, using generalized least squares regression modeling. A detailed characteristic analysis was carried out for motorcycle crashes, using Kansas crash data. Comparisons were made between several aspects of motorcycle crashes and other vehicle crashes. Analysis using Logistic regression was performed on Kansas motorcycle crash data to identify factor affecting fatal motorcycle crashes. In addition, a survey was conducted focusing on identifying motorcycle rider behaviors, helmet usage patterns, perception towards helmet laws in Kansas, potential problems, crash contributory factors, and difficulty levels of different motorcycle maneuvers to execute. Ordered probit modeling was used to identity factors contributing to increased severity of Kansas motorcycle riders involved in crashes. Results from state-level modeling showed statistically significant relationships between motorcycle fatality rates in a given state as well as several other factors. These factors included weather-related conditions, helmet laws, per capita income, highway mileage of rural roads, population density, education, demographic distributions, and motorcycle registrations in the state. The study showed that states with mandatory helmet laws had 5.6% fewer motorcycle fatalities per 10,000 registrations and 7.85% fewer motorcycle fatalities per 100,000 populations. Characteristic analysis of motorcycle crashes in Kansas revealed that motorcycle maneuvers such as overtaking, motorcyclists being older than 40 years, using motorcycle helmets, using motorcycle helmets and eye protection simultaneously, daytime riding, crashes occurring on roadside shoulders, and influence of alcohol among the riders during crashes had higher risk of ending up as a fatal motorcycle crash in Kansas. Results from the survey conducted among motorcycle riders in Kansas revealed that 71% of respondents thought drivers of other vehicles were the single biggest threat to their own safety. Survey results also revealed that 64% of respondents opposed a mandatory law requiring motorcycle riders and passengers to wear helmets in Kansas. Result from the ordered probit modeling of motorcycle rider injury severity showed that overturned and fixed-object motorcycle crashes, helmet use, younger motorcycle riders, speeding, presence of alcohol among motorcycle riders, and good weather contributed to increased severity of injury of motorcycle riders involved in crashes in Kansas.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / Pultruded fiber reinforced polymer (FRP) shapes are gaining popularity in the construction industry. Pultruded FRP profiles introduce a new world of construction that could prove to be a viable option to traditional structural materials. The use of pultruded FRP profiles in structures is discussed in this report. First a brief history of FRPs and their applications are addressed before explaining in detail the two main components of FRP; fibers and resin. The manufacturing process known as pultrusion and how two separate materials become one structural member is examined. As a result of pultrusion, engineers and designers can create structural profiles in customizable shapes, sizes, and strengths to suit any project and price. Theoretically, a pultruded FRP profile can be customized to different strengths within the geometrical and material bounds of the profile; however, many manufacturers publish data regarding mechanical and thermal properties along with allowable loads for their nominal profiles. Currently, there are no governing codes or guidelines for pultruded FRPs but there are design manuals and handbooks published by various committees and manufacturers so the design of pultruded FRP profiles is discussed. Ultimate and serviceability limit states are design concerns that engineers always deal with but concerns of heat or fire, chemical or corrosion, and moisture affect pultruded FRPs differently than steel or wood. Pultruded FRPs pose interesting design concerns because increased customizability and workability means the member can be tailored to meet the needs for that project but that would counter the benefit of mass-produced nominal sizes. A lack of uniform codes and standards inhibits the growth of the pultrusion industry in the United States but codes developed in Europe along with the development of specialized agencies and organizations could help gain a foothold. Lastly, a set of beams varying in length and load exhibit a side-by-side comparison to examine how pultruded FRPs match up next to traditional building materials. Although wood, steel, and reinforced concrete have been the preferred materials of construction, pultruded FRP structural shapes are gaining popularity for its economical and physical advantages, and advances in manufacturing and technology stand to usher in the widespread use of pultruded FRP profiles.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / This report uses and references (Analysis of Vertical Reinforcement in Slender Reinforced Concrete (Tilt-up) Panels with Openings & Subject to Varying Wind Pressures) (Bartels, 2010) to investigate the design philosophy and assumptions used in Section 14.8 of the ACI 318-08 (ACI Committee 318, 2008). The design philosophy and assumptions are analyzed to determine the applicability and accuracy of Section 14.8 of the ACI 318-08 (ACI Committee 318, 2008) to the design and analysis of slender concrete panels with openings. Special emphasis is placed on identifying and quantifying the degree of effect that each assumption has on the final design of the panel. These topics include stress distribution around openings, the effect of varying stiffness of the member on the P-delta effect, stiffness variations due to workmanship and tolerances, and the effect of axial load on the stiffness of the member. This is accomplished through the use of specially designed computer analyses that isolate an assumption or effect to determine its impact on the final design. This study shows that two-way effects are almost non-existant, the portion of the panel above the opening has very little effect on the P-delta effects, the code specified reduction in bending stiffness due to workmanship and tolerances appear to be appropriate, and the effective area of reinforcement overestimates the stiffness of the panel.

Master of Science / Department of Civil Engineering / Mustaque A. Hossain / Over the lifetime of an asphalt concrete (AC) pavement, the roadway requires periodic resurfacing and rehabilitation to provide acceptable performance. The most popular resurfacing method is an asphalt overlay over the existing roadway. In the design of asphalt overlays, the thickness is related to the structural capacity of the existing pavement. As the layers are overlaid, their structural characteristics change due to aging of asphalt. However, currently there is no method to determine the effect of aging on the structural capacity of an existing pavement. This study examined structural characteristics of six test roadways in Kansas using three different test methods: Falling Weight Deflectometer (FWD), Portable Seismic Property Analyzer (PSPA), and Indirect Tensile (IDT) test. The results were analyzed to determine how the modulus of an AC pavement layer changes over time. The results indicate that as the AC pavement ages, its modulus decreases due to pavement deterioration, especially stripping. Two test roadways that showed little signs of stripping had a minimal reduction or even an increase in AC moduli. Thus, the stripping issue needs to be addressed to ensure longevity of AC pavements. While the correlation between test methods studied was mostly consistent for each roadway, no universal correlation was found. The structural coefficient of each AC layer was determined based on the resilient modulus of the layer. It was found the structural layer coefficients do not typically decrease with age at the same rate, and the rate of decrease is a function of the distresses observed.

Doctor of Philosophy / Department of Civil Engineering / Hayder Rasheed / The analysis of concrete columns using unconfined concrete models is a well established practice. On the other hand, prediction of the actual ultimate capacity of confined concrete columns requires specialized nonlinear analysis. Modern codes and standards are introducing the need to perform extreme event analysis. There has been a number of studies that focused on the analysis and testing of concentric columns or cylinders. This case has the highest confinement utilization since the entire section is under confined compression. On the other hand, the augmentation of compressive strength and ductility due to full axial confinement is not applicable to pure bending and combined bending and axial load cases simply because the area of effective confined concrete in compression is reduced. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength and ductility of concrete. Accordingly, the ultimate confined strength is gradually reduced from the fully confined value fcc (at zero eccentricity) to the unconfined value f’c (at infinite eccentricity) as a function of the compression area to total area ratio. The higher the eccentricity the smaller the confined concrete compression zone. This paradigm is used to implement adaptive eccentric model utilizing the well known Mander Model and Lam and Teng Model. Generalization of the moment of area approach is utilized based on proportional loading, finite layer procedure and the secant stiffness approach, in an iterative incremental numerical model to achieve equilibrium points of P- and M- response up to failure. This numerical analysis is adaptod to asses the confining effect in circular cross sectional columns confined with FRP and conventional lateral steel together; concrete filled steel tube (CFST) circular columns and rectangular columns confined with conventional lateral steel. This model is validated against experimental data found in literature. The comparison shows good correlation. Finally computer software is developed based on the non-linear numerical analysis. The software is equipped with an elegant graphics interface that assimilates input data, detail drawings, capacity diagrams and demand point mapping in a single sheet. Options for preliminary design, section and reinforcement selection are seamlessly integrated as well. The software generates 2D interaction diagrams for circular columns, 3D failure surface for rectangular columns and allows the user to determine the 2D interaction diagrams for any angle  between the x-axis and the resultant moment. Improvements to KDOT Bridge Design Manual using this software with reference to AASHTO LRFD are made. This study is limited to stub columns.