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A parametric analysis on 58 beam-column joint specimens has been conducted. The analysis considered 14 fundamental parameters in the design of each specimen and two performance indicators: the horizontal shear strength ratio between the maximum measured strength and the theoretical strength at beam yield, and the nominal curvature ductility of the adjacent beams. Each parameter was varied by a power function, while the linear correlation coefficient between each parameter and performance indicator was recorded. A combined multiple parameter analysis was then conducted to show the interaction of the design parameters and show the representative influences of each parameter based on the magnitude of the applied power functions. Two design equations were constructed from the most influential design parameters, one for each performance indicator. The shear strength ratio was found to be governed by the horizontal joint shear stress, the column axial stress and the yield strength of the longitudinal beam reinforcement. The available curvature ductility of the adjacent beams was also found to be governed by the horizontal joint shear stress, the column axial stress and the yield strength of the longitudinal beam reinforcement, but also the quantity of the horizontal joint shear reinforcement. The influence of the column axial stress on both performance indicators was found to be best represented by a quadratic function. This was because the column axial stress was found to be beneficial up to stress levels of , but axial stress levels exceeding were found to be detrimental to the performance of the beam-column joint, compared to a joint with no axial stress on the columns. The non-linear relationship of the column axial stress agreed with the design assumptions in NZS 3101 for low axial stress values, but at higher axial stress values NZS 3101 assumes a continued performance increase as a result of increasing axial stress, which has been found to be un-conservative. Additionally, an interaction between the column axial stress and the horizontal joint shear stress has been identified. As a result, beam-column joints with high column axial stress levels above 0.40 and horizontal joint shear stress levels in the order of have been shown to fail in a brittle crushing of the concrete in the joint core. Considering this behaviour, it is recommended that the column axial stress levels in earthquake designed beam-column joints should not exceed 0.35 . The results of the parametric analysis were then compared against the current NZS 3101 design equations for conservatism. It was found that a reduction in the horizontal joint shear reinforcement may be possible for beam-column joints incorporating Grade 300 steel in the longitudinal reinforcement of the beams and axial stress levels below 0.25 , but when Grade 500 steel is used or the column axial stress is greater than 0.25 , an increase in the joint shear reinforcement is required compared to NZS 3101. The current NZS 3101 design requirement of at least 40% of the joint shear force, to be resisted by means of joint shear reinforcement, has been found to be appropriate.

Due to an increase in environmental consciousness in the construction industry there has been increasing interest in using natural building materials like rammed earth construction, straw bale construction and hempcrete construction. These materials have very small embodied energy and are carbon negative or carbon neutral. Hempcrete is a bio-composite mix made up of hemp shive, lime, cement and water. There has been extensive research undertaken on the thermal, acoustic, and mechanical properties of hempcrete. It has low density, good thermal and acoustic insulation properties, and can passively regulate humidity in a built environment. However it also has low compressive strength and modulus of elasticity. Thus hempcrete cannot be used as a direct load bearing material but can used as an infill material in timber stud walls. This thesis investigates how hempcrete can have beneficial structural effects by preventing buckling of timber (increasing the buckling load) columns when used as an infill in between columns in a timber stud wall. Eight timber walls were constructed (both half scale -1200mm high; and full scale – up to 2133mm high) with varying column dimensions. Six of the walls were infilled with hempcrete of varying density. Two walls were not infilled and were baseline tests. All walls were tested in compression. It was found that high density hempcrete (715 kg/m3) not only prevented weak axis buckling of columns but also carried some direct load. Low density hempcrete was also successful in preventing weak axis buckling of the infilled walls. In-filled walls failed in strong axis buckling at a load twice (for half scale walls with 38x89mm columns) or 4 times(full scale walls with 38x235mm columns) that of the unfilled walls. An analytical model based on buckling of a strut on an elastic foundation was proposed to predict the maximum strength hempcrete can add to a wall by preventing buckling. The timber column strength equations from CSA –O86-01 closely predicted the buckling load of the walls from the experiments. The results from the model were also put in design equations from CSA –O86-01 to predict practical failure loads if the walls failed by buckling into hempcrete. Although only a single test result was available, it was in good agreement with the model predictions. / Thesis (Master, Civil Engineering) -- Queen's University, 2012-01-30 21:18:13.842

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From various surveys, steel bolted end plate connections are used widely in construction projects throughout the UK. The most popular connections are flush end plated ones with extended end plated ones just behind in popularity. These connections are chosen over other connections types mainly due to their ease of construction and fabrication. The main objectives of this project was to develop a design philosophy to predict column web failure moments based on a series of full scale tests (flush and extend end plates) carried out at the University of Abertay Dundee. Buckling of the column web was observed in a large number of the bolted beam-to-column connections tested. Three dimensional finite element prediction models were developed using the software package ABAQUS, these consisted of 3 flush end plates and 4 extended endplates connections. Investigation of Eurocode 3-Annex J was also undertaken with emphasis on the 7 connections that failed by column web buckling. Comparison between the three different prediction methods were investigated, this involved comparing physical test, Eurocode 3 and finite element results (ABAQUS).

Contamination of surface and ground water has emerged as one of the most important environmental issues in developed and developing countries. Bioremediation of groundwater takes advantage of bacteria present in the environment to transform toxic compounds to non-toxic metabolites. This biotechnology holds the potential for fast, inexpensive, and effective water decontamination. However, it is still poorly understood and usually not fully controlled due to the lack of information describing the natural phenomena involved. Therefore, a better understanding of the phenomena involved during bioremediation of groundwater could help in the design and implementation of more efficient technologies. The main objective of the present research is to assess how pore-scale physical factors, such as pore-scale velocity, affect the degradation potential of contaminants during transport in groundwater. The target chemicals studied were chlorinated ethenes because they are commonly found in contaminated groundwater sites. To achieve the research objective, the following were employed: a mathematical model that links pore scale processes to the macro-scale representation of contaminant transport; development of numerical tools to solve the mathematical model; and experimental elucidation of the influence of pore-scale flow velocity on the biodegradation of contaminants using column experiments. Results from the mathematical model and experiments were used to elucidate the inter-relationship between physical and biological phenomena at the micro scale. The influence of flow velocity through the porous media (a physical factor) on the biological structure (microbial community in the porous media) was assessed. The results of this investigation contribute to the bioremediation of contaminated groundwater understanding with new insights on the importance of physical transport factors on the biodegradation potential. For example, flow velocity is shown to have an important effect on the degradation potential of chlorinated ethenes. Additionally, the mathematical model and numerical tools have potential application to many other reactive transport problems, including: adsorption onto activated carbon, reaction in packed beds of catalyst, chemical transport in streambeds, and separation in chromatographic columns.

In this thesis, a device by applying the oscillating water column in a well-like resonant chamber installed in a floating structural system is studied experimentally. The device was designed to utilize the oscillation motion of the water inside the resonant chamber and then the pressure variation of the air to drive the air-turbine system. When connected to a electric power generation system this device may convert the wave power to electric power. A theory assuming independence between the motion of floating structure and the heave of waves inside the resonant chamber, derived by McCormick (1976 ) is adopted in this study. During the experimental tests four groups of test were carried out depending on the parameters that are to be evaluated for the effectiveness of the power conversion, namely, the rotation speed of the turbine with or without the power generator attached, the relative wave-height variation between the incident wave and waves in the well-like resonance chamber and the actually generated electric potential. For each group of test five sets of wave-height from 6 cm to 10 cm and four sets of period of wave, namely, 0.89, 0.92, 1.06, 1.20-second are applied.