Thesis (M.E.F.E.)--University of Canterbury, 2006. / Typescript (photocopy). "January 2006." Includes bibliographical references (leaves 99-101).

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Master of Science / Department of Civil Engineering / Hani Melhem / The combination of cold formed steel (CFS) with structural wood panels exhibits a degree of partial composite action behavior. In the current design and construction codes, CFS and wood sheathing systems are considered separate, in a non-composite manner, due to the absence of sufficient supporting experimental and research data. The problem with previous research is the lack of information to fully define the composite action between CFS and wood sheathing. The scope of this study is to check fundamental information provided in previous research. The approach adopted to solve the problem follows previous experimental procedures conducted at Kansas State University. The objective of the research is to determine the slip modulus with various fastener spacing. Additional results obtained in this study are compared to previous research results.

O trabalho tem por objetivo o estudo teórico e experimental de pontes protendidas de madeira para pequenos vãos utilizando madeiras de reflorestamento. Para esta finalidade foram avaliados os parâmetros elásticos destas madeiras e o efeito da presença de juntas de topo na rigidez longitudinal do tabuleiro da ponte. A metodologia utilizada para obter os parâmetros elásticos é a experimentação em laboratório de placas ortotrópicas submetidas à torção. Os efeitos das juntas de topo foi verificado em ensaio de modelo reduzido e comparado a uma simulação numérica em computador utilizando o programa AnSYS 5.2 de elementos finitos, módulo Shell, com propriedades ortotrópicas. Finalmente é proposto um critério de dimensionamento para estas estruturas a partir dos resultados experimentais obtidos e de disposições de códigos internacionais. / The aim of this work is the theoretical and experimental study of prestressed timber bridges to small spans using reforestation species. To this purpose elastics characteristics are analysed as well the butt joint effects on timber deck stiffeness. The experimental methodology was used to find the elastics characteristics is torsional tests in orthotropic plates. The butt joints effects was made in a reduced model and the results compared with a computer numerical analysis using the software AnSYS 5.2, shell module, with ortotropic characteristics. Finally, a design criteria was proposed to these structures using the experimental results obtained and the international codes recomendations.

The use of Fibre Reinforced Polymers (FRP) has grown in popularity in the construction industry. FRP has proven useful in the retrofit of various types of structural elements. It may be used for the strengthening of beams, the seismic upgrade of walls panels, as well as the jacketing of columns to provide confinement. There exist several methods of FRP application for the case of structural retrofits. These include the application of pre-prepared FRP mats, or application of FRP via the wet lay-up process. However, a new technique developed at the University of British Columbia allows for the application of FRP in the form of a spray. Externally bonded Sprayed FRP (SFRP) is known to increase strength and energy absorption capacity of a retrofitted member as well as, or better than, FRP sheets. However, tests have primarily been carried out on concrete members only. An area of interest, into which not much research has been conducted, is the application of SFRP to timber. Timber bridges are extensively used in many parts of the world. Often due to remoteness and practical constraints, it is impossible to apply FRP sheets to retrofit these bridges. SFRP would be a much easier method of FRP application. This study looked at the application of SFRP to Douglas Fir (D.Fir) Beam specimens subjected to 3-Point Flexural Loading only. The specimens were treated with either a water based (Borocol) or oil borne (Creosote) antifungal preservative prior to being sprayed with FRP. Different combinations of adhesives/bonding agents including Hydroxymethylated Resorcinol and Polymeric Isocyanates were used to try to develop a strong bond. When considering using only chemical adhesives to obtain a proper bond between the two constituents of the composite, use of HMR is recommended for timber which is untreated or has been treated with a water borne preservative such as Borocol, while a pMDI adhesive such as AtPrime 2 is recommended for timber treated with an oil borne preservative such as Creosote. For Non Creosoted beams, adhesives did not generate as significant of a strength gain. For Creosoted beams, adhesives may be sufficient to generate significant strength gain when SFRP is applied to a beam. Considering that most structures in use would probably have been treated with a preservative similar to Creosote, in practice, AtPrime 2 or some other some sort of pMDI would probably be the adhesive of choice. Based on the results of the study, it is possible to say that the application of SFRP to retrofit/rehabilitate timber structures shows considerable promise. If a decent bond is achieved between the composite constituents, it is possible to substantially increase the ultimate flexural strength of the member, as well as drastically increase its ductility and energy absorption capacity. It is recommended that further tests be carried out using different types of loading schemes, geometrical configurations of SFRP, other types of anchorage, and development of a proper analytical model before the method is adopted for widespread use. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

This thesis explores how natural light can be integrated with built form to create a “performance of light” in architecture. Lighting conditions from a contemporary dance piece, as well as other architectural precedents, were studied, and aspects adapted into the building’s design. In addition to designing theatrical effects of light, the classroom and administrative spaces were designed to take advantage of natural light. Daylight studies were used to inform glazing design and material selection to stay within illuminance thresholds in the spaces. This project is responding to the facility needs of the campus of UMass Amherst where the program of the dance, theater and music departments are stressed for space, are operating in below-average facilities, and are separated, making collaboration difficult. The programmatic concept driving this design purposely mixes offices, classrooms and rehearsal spaces, creating overlap and collaborative opportunities. The use of mass timber was also an important aspect of the buildings’ design. Wood brings along many benefits, such as lower embodied energy, carbon sequestration, better thermal properties, and an increase in the perceived quality of architectural spaces. The volume of wood used in the building’s structural system was run through a life-cycle analysis to determine the overall carbon footprint, in relation to the amount of steel and concrete used.

Timber-frame brick veneer construction originated in countries in which houses were traditionally constructed with loadbearing timber frames which were clad with non-loadbearing weather boarding or similar light-weight materials. Timber-frame house construction is extensively used in countries such as Canada, Scandinavia, Australia and North America. With the Canadian system, buildings of up to three storeys can be erected with loadbearing timber frames. This particular system was also adopted in France - the Igny project~ and in England - the Harlow project. In most of these cases, basements or crawl-spaces underneath the house were incorporated in the design. In these countries there have a trend towards the use of a brick cladding (veneer) for timber-frame structures. This is a comparatively recent introduction in these countries, but it has already been extensively used. This trend is primarily related to the appearance and other advantages (for example durability and ease of maintenance in the case of a face-brick clauding) of a masonry exterior, while largely retaining the low cost benefits of timber-frame construction.

A group of 22 independent southeastern U.S. logging contractors provided 44 contractor-years of detailed cost and production information. Information was collected on demographics, operational characteristics, and business strategies for the participants. Precipitation was statistically proven to not be a good predictor of production, accounting for 2% of the weekly variation. High production through periods of favorable harvesting did not occur. Loggers contracting for the same mill in the same general area had higher than average production in the winter months and lower than average production in the summer months. Summary analyses for the entire population found that the cost of producing an additional ton dropped in 1997 by $0.90, but fixed annual costs rose. Predicting costs on the basis of production for the population was misleading. A comparison of total costs for individual firms with the population average (regression equation) found that the equation underestimated costs by as much as $408,000 and overestimated costs by as much as $528,000. Contracted services expenditures increased in 1997, as expenditures for equipment, consumables, and labor decreased. Over the study period, total costs per ton increased by 3.7%, but total production increased by 3.9%. The relationship between key cost components revealed strong evidence to disprove previously held theories. A major portion of the population increased production but experienced increased costs per ton. Replacement purchases of equipment tended to be of similar capabilities and technology and did not reduce labor costs. Trends in supply and equipment costs per-unit were not found in the expected fashion. / Master of Science

Numerous attempts to explain the decision making framework of public agencies with multiple goals have been published in recent years. The central problem of the multiple goal decision process of public agencies is the problem of unvalued benefits stemming from projects which the agency could potentially implement. Regardless of the complexity of the problem, the fact remains that choices must be made between projects. As a result, several alternative procedures for analyzing the issue have been suggested. These may be subdivided into three more or less different approaches: (1) estimation of value indexes or weights for the arguments of the objective function, (2) constrained optimization models, (3) political decision procedures. The last alternative provides the setting for the discussion that follows. The object is to suggest procedures for incorporating better information in valued and non-valued benefits into public resource. Agency programs of the United States Forest Service are analyzed in terms of their valued benefits and their impact on regional employment. Given that there are significant dependencies in certain Colorado communities on the timber industry, how important is Forest Service timber-harvesting policy for these industries and communities? This question is the basis for the objectives of this thesis. These objectives may be stated as: 1. to quantify the cost of providing for regional income objectives via timber harvesting and investment, and 2. To determine the distribution of benefits from public timber harvesting-investment programs. Are the benefits accruing to particular local economies, or are they leaking out of the region? A present value model is used to value timber investment alternatives. When present values are negative and it can be argued that the investments were undertaken to provide for timber originating employment objectives. To analyze incidence of benefits, regional ownership of capital resources in lumber manufacturing and harvesting are first identified. The proportion of incremental income generated by timber investments which is allocated to non-resident capital is then identified by analysis of factor shares. Analysis of employment sustained by timber harvesting and investment confirmed the generally accepted conclusion that Forest Service timber policy can be an important factor in regional economies. The present value analysis indicated that timber investment alternatives in Colorado typically yield negative values at reasonable discount rates. The distribution of benefits from Forest Service timber policy is not limited to the local regional economies which are presumably of primary concern. Sixty-one percent of the capital int he lumber manufacturing sector of Colorado was found to be owned by outside interests. It was also found that at least ten percent of the harvesting in the state is carried out with non-local capital. When these results are combined with the finding that approximately twenty-four percent of the benefits or value-added by the lumber and wood products sector are allocated to capital it is seen that fifteen percent of the value-added in lumber manufacture and around two and one half percent of the value-added in harvesting are distributed to non-local individuals whose welfare is probably not a concern of decision makers.

Glue laminated wood deck systems are commonly used for bridge decks on girder bridge systems. These decks are usually covered with a hot-mix asphalt wearing surface in conjunction with a bituminized fabric sheet waterproofing membrane. Often cracks occur in the asphalt at the intersection of two adjacent deck panels which limits the useful life of the wear surface, provides a poor riding surface and potentially allows moisture to flow to wooden bridge components. The purpose of this study was to investigate the structural behavior of asphalt/wood/membrane deck systems. This was accomplished experimentally by determining the deflection of bridge deck panels with respect to each other under simulated truck loading. A classical linear analysis model and a finite element analysis model were developed for the deck panel deflections. These analytical results were compared to the experimental results and a value of approximately 0.05 in for the interpanel differential deflection was determined to be a reasonable, conservative value for the typical configuration considered. This deflection was then used to load various asphalt/membrane/ wood configurations to investigate the effectiveness of the arrangement with regards to resisting hot-mix asphalt cracking. It was found that when subjected to repeated deflections of 0.05 in, the following experimental composite bridge deck performed best in terms of reduced cracking: 1) hot-mix asphalt base layer applied directly onto the glulam deck panel; 2) waterproofing membrane placed on the base layer of asphalt; 3) hot-mix asphalt surface layer placed on the waterproofing membrane. / Master of Science