This study investigates the effects of typical construction details on the strength of steel deck reinforced concrete composite slabs. Past research on composite slabs has been centered primarily around single span, single panel width slabs with unrestrained ends. The test specimens in this study are more representative of actual slab construction. The effects of multiple spans, multiple panels, end restraint from pour stops, and deck anchorage from shear studs and welds are investigated. The results of this experimental study are analyzed using methods given in the Steel Deck Institute Composite Deck Design Handbook. The models were found to conservatively predict the strength of the composite slabs. Recommended modifications to the calculation methods are given. / Master of Science

A fully automated computer program is developed for the optimum design of steel space trusses acting compositely with a concrete slab placed on top. The program sizes the truss members to meet the requirements of the load and resistance factor design specification of the American Institute of Steel Construction using the load combinations of ANSI. Earthquake loading is not considered. The optimum size is based on minimum cost, regarding the amount of welding required at the joints and of the member itself. The total cost is based on all steel work in the truss. Once the truss configuration has been defined, and it has been ensured that linear elastic behavior exists, the structure is analyzed for the construction process, to make sure that no overstressing will take place in any structural element at any time during construction and service. The analysis and design principles are presented and an actual design case is solved. (Abstract shortened with permission of author.)

published_or_final_version / abstract / Civil Engineering / Master / Master of Philosophy

With the need to improve corrosion resistance in columns and piles, the innovative idea of Centrally Prestressed Fiber Reinforced Concrete (CPFRC) columns is a promising solution. The first step is to compare if the compressive strength of any mix is affected by the size, geometry, or even the inclusion of polyolefin fibers in a specimen. The results showed that the cylinder size of 4 in. x 8 in., which is the most common size used by the testing labs, has the highest compressive strength. There was no sign on compressive strength improvement with the use of polyolefin fibers, except for reduction in cracking size and concrete spalling. The second step compared the ultimate strength, ductility characteristics and failure mode of CPFRC columns to conventional columns. CPFRC showed adequate axial and flexural resistance, in addition to ductile behavior similar to regular reinforced concrete columns. / by Daniel A. Grijalba. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2005. / Includes bibliographical references (p. 101-102).

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2006. / Includes bibliographical references (p. 121-122).

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 115-117).

The main objective of this study is to develop an analytical model to explain the behavior of a hybrid structure under different loading conditions. The model developed for a simply supported beam on moment capacity, stiffness, and deflection can be generalized to deal with any type of material combination. The dependence of moment capacity of the hybrid beam on the thickness of the composite sheet was investigated. The inherent property of a high Young's modulus and strain-to-failure properties of the composite material increased the moment capacity of the RC beam dramatically. The moment model showed a percentage increase of 284% for KFRP while on the other hand the percentage increases for CFRP and GFRP were 191% and 174% respectively when using a FRP sheet of thickness 0.025 mm. KFRP showed the highest increase in moment capacity because of its high strain-to-failure. CFRP on the other hand has a high Young's modulus, but its strain to failure is low, causing it to lie in the middle range. The analytical model is that the ability of a beam to handle moment is strongly dependent on the strength characteristics and the thickness of the FRP sheet. / Master of Science

The aim of this study was to investigate the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulate the splash, tidal, atmospheric, and immersed portions of a marine structure. To study the atmospheric deposition, the project also investigated the relationship between chloride ion deposition on the wet candle and its accumulation into concrete samples. Results from the wet candle experiment indicated that between 2% and 45% of the chlorides deposited per square meter of exposed area could be found within the concrete samples. After 6 months, slag G1a blocks showed the most resistance to chloride penetration in the tidal and splash simulations. After 10 months of exposure, fly ash samples had the slowest rates of diffusion in the tidal simulation while the fly ash + silica fume samples and the slag samples measured similar rates of diffusion within the tidal zone. After 90 days of curing, cylinders composed of 20% fly ash & 8% silica fume measured the highest average resistivity values and were found to be less vulnerable to chloride ion penetration than the 20% fly ash and the 50% slag concrete through rapid migration tests. / by Victor Anthony Echevarria. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

This work is an experimental study of applying an impedance-based health monitoring technique to complex structures. The work is presented in three parts. In the first part we consider effects of the following three factors on damage detection abilities: actuator excitation level, test wire length and ambient conditions (temperature, structural loading and vibration). It was concluded that increasing the applied voltage improves the signal to noise ratio and damage detection abilities. Test wire lengths under 30m do not affect damage detection abilities. The technique is able to distinguish and detect damage even with variations in temperature, structural loading and vibration. In the second part we apply our health monitoring technique to a complex truss structure and a massive steel steam header. We discovered that with multiplexing (acquiring a single signal from distributed actuators) the actuators on the truss structure we could detect damage but with less location information. Damage detection on the steel pipe ended in inconclusive results. The use of this technique on massive structures needs further investigation. Finally, we conducted a detailed experimental study of monitoring the integrity of composite-reinforced masonry structures. We developed a software package which enables even a casual user to determine if significant damage has occurred in these structures. The technique was successfully applied to detect damage (particularly due to delamination) in these composite-concrete structures. Most significantly, the technique was also able to detect damage well in advance of actual failure. This work relies mainly on frequency response plots and damage metric charts to present the data and to arrive at any conclusions. While frequency response plots give a qualitative approach to the analysis, damage metric charts attempt to quantify the data. / Master of Science