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A Study On The Utilization Of Waste Cement-bonded Wood Particle Board As A Raw Material And A Secondary Fuel In Cement ManufacturingYilmaz, Mustafa 01 September 2012 (has links) (PDF)
A considerable amount of waste is obtained as a result of edge-cutting operations during cement-bonded wood particle board (CBWPB) manufacturing. This waste material which basically contains wood chips and hydrated cement has to be disposed of and does not have any economical value. However, it can be burned in cement rotary kilns and may result in energy savings to a certain extent due to the presence of wood particles as a secondary fuel and since the hydrated cement may be decomposed and then reform clinker compounds during the calcination process.
In this experimental study, the possibility of using waste CBWPB in cement manufacturing and its effects on energy consumption and cement characteristics will be investigated. The reference mix, corrective limestone, CBWPB waste and coal, were used as raw materials to prepare six different raw meals whose chemical compositions was similar to reference mix. All six raw mixes (including the reference) were calcined under the same conditions to produce clinkers. The compositions and micro structure of the clinkers obtained were comparatively analyzed by wet analysis, XRF and XRD techniques. Cements were obtained by intergrinding the clinkers with 5% (by mass) gypsum rock and standard tests were carried out on each of the cements. In addition to these, since CBWPB waste contains wood about 30% by weight, its contribution to fuel consumption during clinker production was also analyzed.
The test results revealed that CBWPB waste can be used as a cement raw material since CBWPB waste has the similar chemical composition with the reference raw mix. CBWPB, which contains about 30% (by mass) wood, contributes to the heating process during calcination and results in lower amount of primary fuel requirement.
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Characterization of Mixed-Mode Fracture Testing of Adhesively Bonded Wood SpecimensNicoli, Edoardo 19 August 2010 (has links)
The primary focus of this thesis was to investigate the critical strain energy release rates (G) for mixed-mode (I/II) fracture of wood adhesive joints. The aims of the study were: (1) quantifying the fracture properties of two material systems, (2) analyzing the aspects that influence the fracture properties of bonded wood, (3) refining test procedures that particularly address layered orthotropic systems in which the layers are not parallel to the laminate faces, of which wood is often a particular case, and (4) developing testing methods that enhance the usefulness of performing mixed-mode tests with a dual-actuator load frame. The material systems evaluated experimentally involved yellow-poplar (Liriodendron tulipifera), a hardwood of the Magnoliaceae family, as adherends and two different adhesives: a moisture-cure polyurethane (PU) and a phenol/resorcinol/-formaldehyde (PRF) resin. The geometry tested in the study was the double cantilever beam that, in a dual-actuator load frame, can be used for testing different levels of mode-mixity. The mixed-mode loading condition is obtained by applying different displacement rates with the two independently controlled actuators of the testing machine.
Characteristic aspects such as the large variability of the adhesive layer thickness and the intrinsic nature of many wood species, where latewood layers are alternated with earlywood layers, often combine to confound the measures of the critical values of strain energy release rate, Gc. Adhesive layer thickness variations were observed to be substantial also in specimens prepared with power-planed wood boards and affect the value of Gc of the specimens. The grain orientation of latewood and earlywood, materials that often have different densities and elastic moduli, limits the accuracy of traditional standard methods for the evaluation of Gc. The traditional methods, described in the standards ASTM D3433-99 and BS 7991:2001, were originally developed for uniform and isotropic materials but are widely used by researchers also for bonded wood, where they tend to confound stiffness variations with Gc variations. Experimental analysis and analytical computations were developed for quantifying the spread of Gc data that is expected to be caused by variability of the adhesive layer thickness and by the variability of the bending stiffness along wooden beams. / Ph. D.
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Energeticky efektivní horská chata / Energy efficient mountain chaletNěmec, Ondřej January 2014 (has links)
Master´s thesis is based on the design of energy efficient huts in the mountain resort Čenkovice . The specified property is currently located existing building mountain rescue . Land is the bigger size , medium steep , overgrown with trees higher . The existing building is of timber construction and is already inadequate to the needs of mountain rescue . The concept of the new HS object is to achieve the lowest power consumption of utility power to operate the building and to endeavor the least possible burden on the environment during construction. The new building is designed largely from natural materials , mostly of wood that form the supporting structure and it is well insulated. The house is rectangular in shape , with 2 floors and galleries. The first floor serves HS , second floor stay for ski school instructors . The rooms are oriented to the southwest side . The building uses solar energy to power and ventilation is forced.
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