published_or_final_version / Civil Engineering / Master / Master of Philosophy

This project researches structural floor systems utilized during the late eighteen hundreds and into the early nineteen hundreds. Historical background and general design information is included along with information on materials used in the systems and data sheets for these materials illustrating their properties. The floor systems, which were found to be in use during this time period, are presented individually including a description of the system, its materials and properties associated with the system. Five case studies have been included to illustrate how this project can be utilized to identify the type of floor system used within a historical building and the structural evaluation process that may follow.This creative project was completed in order to serve as a guiding tool in the evaluation process of the floor system of a historical structure. It is intended and formatted to be used by structural engineers, forensic engineers and others with a sufficient understanding of structural issues. The systems discussed are original and often diverse from those utilized in construction today. This in itself is important to understand when preparing to evaluate and renovate a historical structure. / Department of Architecture

The development of high strength, light weight materials has generated more efficient designs of steel joist-concrete slab floor systems. Though the structural integrity is rarely compromised, these floor systems are more susceptible to human-induced vibrations which may be annoying to the occupants of the structure. The purpose of this investigation was to develop methods of improving the vibration characteristics of joist-supported floor systems. The frequency and first maximum amplitude of vibration can be altered by redesigning the cross-section of the floor system in order to improve its acceptability. However, damping has the greatest effect on the perceptibility of occupant-induced floor vibrations. Therefore, this study focussed on devising methods of increasing damping in joist supported floor systems. Steel joist-metal deck-concrete slab test floors were constructed for the purpose of this investigation. In addition, a two-bay building was constructed so that the developments of this research could be field tested. The experimental results were presented and recommendations were made for future work in this field. / Master of Science

M.Ing. / This research project was initiated by a well-known international company (MAKRO SA), which had experienced floor joint problems occurring in their industrial floors. Floor joint problems i.e. joint damage and spalling of the joint area result, from a combination of construction workmanship and quality control problems, as well as from operational hard wheeled vehicle loading conditions. Damaging and spalling of joint edges are general problems occurring on warehouse floor slabs because of hard wheeled loads trafficking joints. In addition, joint filler detachment from the joint wall surface looks aesthetically poor and leaves the possibility of hygienic problems developing. In the case of MAKRO SA stores, the above problems are not acceptable and should be avoided at all costs. The objective of the report is to investigate solutions to solve the problem of joint damage in industrial floors due to problems occurring in practice, as described below. Floor joint edge problems are a result of three main reasons. First, subsoil quality. The quality of the subsoil is determined by the compaction effort and type of filler materials used, which in turn determine the amount of deflection that will be detected at joint edges. Subgrade quality determines whether deflection of the top concrete layer will occur. Poor compaction and filler material contributes to excessive deflection occurring due to inadequate support of the concrete floor slabs. Water penetration through the floor slab results in the fines of the subsoil being eroded or washed out, resulting in a less dense material, which will deflect under large vehicle and store racking loads. It is concluded that good quality subsoil conditions will result in less deflection and level irregularities of the top concrete floor slab, resulting in less joint damage and spalling. Secondly, the effect of floor and joint workmanship on damage and joint edge spalling. Level irregularities occur due to poor troweling or floating efforts at the joint area. Poor joint edge workmanship results from incorrect formwork removal from the joint wall resulting in a damaged joint edge and additional spalling of the joint to that occurring from wheel load impact. Joints undergo damage as forklifts traffic the joint area as wheel load and energy

This research evaluated the feasibility of the empirical design method for reinforced concrete bridge decks for the Florida Department of Transportation [FDOT]. There are currently three methods used for deck design: empirical method, traditional method and finite element method. This research investigated and compared the steel reinforcement ratios and the stress developed in the reinforcing steel for the three different methods of deck design. This study included analysis of 15 bridge models that met the FDOT standards. The main beams were designed and load rated using commercial software to obtain live load deflections. The bridges were checked to verify that they met the empirical method conditions based on the FDOT Structures Design Guidelines – January 2009. The reinforced concrete decks were designed using the traditional design method. Then the bridges were analyzed using three-dimensional linear finite element models with moving live loads. The reinforced concrete decks were designed using dead load moment, live load moment, and future wearing surface moment obtained from the finite element models. The required reinforcing steel ratio obtained from the finite element method was compared to the required reinforcing steel ratio obtained from traditional design method and the empirical design method. Based on the type of beams, deck thicknesses, method of analysis, and other assumptions used in this study, in most cases the required reinforcing steel obtained from the finite element design is closer to that obtained from the empirical design method than that obtained from the traditional design method. It is recommended that the reinforcing steel ratio obtained from the empirical design method be used with increased deck thicknesses to control cracking in the bridge decks interior bays.