<p>Introduction: Dolomite AB was in need of a dummy arm for crutch testing, to complement their existing test capabilities. Background: A large number of people need crutches on a daily basis. For them it is essential that their crutches do not fail. ISO (the International Organization for Standardization) conducts ongoing work to guarantee the durability and function of e.g. crutches. ISO has recently adopted a new standard for testing if elbow crutches. This has already met resistance, it has been claimed that the tests in it should include loading of the crutch in the frontal plane. Aim: To enable Dolomite to test elbow crutches in accordance with guidelines in ISO/FDIS 11334-1. And examine the magnitude of loads on a crutch in the horizontal- sagittal- and frontal plane. This to see if loading of the crutch in the fontal plane should be included in a new ISO-test. Goal: To fabricate a dummy arm for testing of elbow crutches. To gain knowledge of the magnitude of the load a crutch is subject to in the horizontal-, sagittal-, and frontal plane. Method: A dummy arm was made using methods and tools described in DPD (dynamic product development), and conventional fabrication methods. A test equipment was made, which registered the loads on a crutch, in three directions. Eleven persons, constituted the test group, one was excluded. Result: A fully functional dummy arm was manufactured. The average maximum load for the ten test subjects was: 33 kilos downwards, 12 kilos backwards and 2 kilos side wards. Discussion: The choice of materials was influenced by the strength demands, ease of manipulation, access and price. Dummy arm design was mostly a question of durability and function. The test group was made up of persons available when the test was done The crutch loading test indicates that the forces applied to a crutch In the frontal plane are small, compared to forces in the horizontal- and sagittal plane, almost negligible. Conclusion: A fully functional dummy arm was fabricated, no need for a new ISO-test for standard crutches was identified.</p>

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This thesis proposes that the concept 'permanence' is relevant at the beginning of the twenty first century. It examines why the term, while perhaps pertinent in addressing the disposability of architecture in Western society, seems anachronistic. The study reviews the seeming inaccessibility of the term in its contested and plural interpretations, and reviews problems in its definition and relevance. <br /><br /> A close examination of definitions, interpretations and contemporary approaches is provided in order to create a conceptual framework that reveals complex implications of the term. Four strategies for understanding the concept are offered: 'realms versus modes', definitions, a distillation of four positions relating to permanence, and an inquiry into contemporary issues relating to the concept. 'Absolute' and 'relative' realms illuminate a scope for permanence, and 'static' and 'dynamic' modes are discussed. A series of definitions are reviewed that reveal nuance in implications. An analysis of four essays on permanence is included, one from the beginning of the twentieth century and three from the end. This section reveals a series of conflicts relating to the way contemporary Western society uses and understands the term. <br /><br /> Permanence within architecture is widely associated with the Vitruvian definition of <em>firmitas</em>: mass and solidity crafted to endure eternally. Vitruvius' employment of 'permanence' is used as a grounding definition and a fundamental reference for the term's evolution into contemporary usage. In observing the endurance of the original Vitruvian term today, a disconnect becomes evident: absolutism in a society defined by relativity. This thesis argues for the critical significance of the term at a pivotal point in history in addressing the problem of disposable architecture on both a cultural and ecological level. Final open-ended questions are raised that consider staggering construction and demolition waste statistics, implying that permanence could play a significant role in effective responses to a global environmental crisis.

Abstract, <br /> The interest in using recycled construction materials is derived from the growth in construction and demolition waste due to rehabilitation and natural and technological disasters. The driving force for recycling concrete is three-fold: preserving natural resources, utilizing the growing waste and saving energy and money. While some waste concrete is currently being crushed and used for grading and base material for highways, it has not been used as the aggregate in new concrete in Canada, largely because of the plentiful supply of good quality virgin material. However, crushed concrete is being used in new concrete in other parts of the world where the local aggregate is inferior, and there is now a push within the Canadian cement and concrete sector to improve the industry sustainability, one aspect of which is recycling of materials. <br /><br /> The research done to date has emphasized the influence of recycled concrete aggregate (RCA) on the workability and strength of the new concrete with little attention being paid to the behaviour in service. In contrast, the present study is focused on the durability of concrete containing RCA in reinforced structures. Since the most common cause of failure of reinforced concrete structures in this part of the world is corrosion of the reinforcement by de-icing salts, the focus of the project is on this aspect of durability. The project involves a comparative study of the durability of three concrete mixtures containing, as coarse aggregate: <ol> <li>new clean recycled concrete aggregate (NC-RCA) obtained by crushing the excess concrete returned to the ready mix yard; </li> <li>old de-icing salt contaminated, recycled concrete aggregate ( OC-RCA) from a demolished bridge over Highway 401 in Ontario; </li> <li>natural aggregate as a control material. </li> </ol> These three materials were crushed and sieved to give the same grading for each mix. Natural sand was used as fine aggregate. The mixes were adjusted to account for the different water absorption characteristics of the aggregates but were otherwise identical. Prism specimens with a centrally placed reinforcing bar, cylindrical specimens and non-reinforced slabs were cast from each of the concretes. After curing, the reinforced prisms were exposed to a saturated de-icing salt solution for two of every four weeks. For the second two week period, they were allowed to dry in the laboratory atmosphere or, to accelerate the process, dried at 32°C in a low humidity (18%) chamber. <br /><br /> The electrochemical corrosion behaviour of the steel was monitored using linear polarization resistance and cyclic polarization techniques. In addition, the physical properties of the materials were assessed. For the aggregates, water absorption, chloride content and susceptibility to abrasion were determined. For the concretes, compressive strength, salt scaling resistance and chloride permeability were measured and microscopic observation of the interfacial zones between the aggregate and the new cement paste were conducted. <br /><br /> On the basis of the results, it is concluded that the durability and the strength of the RCA concrete is very dependent on the age of the RCA aggregate. Water and chloride permeability, and, salt scaling and reinforcing steel corrosion resistance of concrete made with a very well hardened old RCA were comparable with or better than those of in normal concrete. Concrete incorporating new RCA exhibited inferior properties and consequently, it is recommended that, the OC-RCA concrete can be used as a sustainable material in structural applications.

Hundreds of ready-mix concrete trucks are dispatched daily from ready-mix concrete plants. On average, a concrete truck has a carrying capacity ranging from 7 to 9 cubic metres of concrete, requiring about 1500 litres of water. In addition, 500 to 1300 litres of water are used to wash out the excess concrete when the truck returns. Based on these figures, it is clear that the ready-mixed concrete industry consumes large amounts of fresh water. The purpose of this study is to determine the feasibility of using the wash water as mixing water in new concrete. The specific goal of this project is to determine the influence of the high pH and dissolved solids content of the wash water on the durability of concrete, particularly with respect to de-icing salt induced corrosion of steel reinforcement. Two types of mix designs were used in this research: a standard class N and a higher strength, structural C2 concrete. Two sets of concretes specimens were made with both mix designs: one with wash water and one with clean water. The project consists of a multi-component experimental program, beginning with wash water characterization, then pore solution and cement chemistry, followed by an evaluation of the effect of wash water on concrete workability and mechanical properties, resistance to de-icing salt scaling, and corrosion of reinforcing steel embedded in the concrete. In addition, the effect of the wash water on the effectiveness of air entraining agents (AEA) is being determined using air void analysis of specimens with different AEA contents. On the basis of the results obtained from the comparative study using wash water versus tap water, it appears that wash water can be used as mixing water for the production of concrete without compromising the durability properties related to corrosion and salt scaling performance. In addition, the mechanical and plastic properties of wash water concrete meet all standards pertaining to the use of wash water concrete and are similar to those of tap water concrete. Finally, the pore solution, thermal analyses, and water analyses of wash water and tap water showed comparable results. Overall, with regards to the tests conducted thus far, the use of wash water as mixing water in concrete poses no durability concerns.

This thesis proposes that the concept 'permanence' is relevant at the beginning of the twenty first century. It examines why the term, while perhaps pertinent in addressing the disposability of architecture in Western society, seems anachronistic. The study reviews the seeming inaccessibility of the term in its contested and plural interpretations, and reviews problems in its definition and relevance. <br /><br /> A close examination of definitions, interpretations and contemporary approaches is provided in order to create a conceptual framework that reveals complex implications of the term. Four strategies for understanding the concept are offered: 'realms versus modes', definitions, a distillation of four positions relating to permanence, and an inquiry into contemporary issues relating to the concept. 'Absolute' and 'relative' realms illuminate a scope for permanence, and 'static' and 'dynamic' modes are discussed. A series of definitions are reviewed that reveal nuance in implications. An analysis of four essays on permanence is included, one from the beginning of the twentieth century and three from the end. This section reveals a series of conflicts relating to the way contemporary Western society uses and understands the term. <br /><br /> Permanence within architecture is widely associated with the Vitruvian definition of <em>firmitas</em>: mass and solidity crafted to endure eternally. Vitruvius' employment of 'permanence' is used as a grounding definition and a fundamental reference for the term's evolution into contemporary usage. In observing the endurance of the original Vitruvian term today, a disconnect becomes evident: absolutism in a society defined by relativity. This thesis argues for the critical significance of the term at a pivotal point in history in addressing the problem of disposable architecture on both a cultural and ecological level. Final open-ended questions are raised that consider staggering construction and demolition waste statistics, implying that permanence could play a significant role in effective responses to a global environmental crisis.

Abstract, <br /> The interest in using recycled construction materials is derived from the growth in construction and demolition waste due to rehabilitation and natural and technological disasters. The driving force for recycling concrete is three-fold: preserving natural resources, utilizing the growing waste and saving energy and money. While some waste concrete is currently being crushed and used for grading and base material for highways, it has not been used as the aggregate in new concrete in Canada, largely because of the plentiful supply of good quality virgin material. However, crushed concrete is being used in new concrete in other parts of the world where the local aggregate is inferior, and there is now a push within the Canadian cement and concrete sector to improve the industry sustainability, one aspect of which is recycling of materials. <br /><br /> The research done to date has emphasized the influence of recycled concrete aggregate (RCA) on the workability and strength of the new concrete with little attention being paid to the behaviour in service. In contrast, the present study is focused on the durability of concrete containing RCA in reinforced structures. Since the most common cause of failure of reinforced concrete structures in this part of the world is corrosion of the reinforcement by de-icing salts, the focus of the project is on this aspect of durability. The project involves a comparative study of the durability of three concrete mixtures containing, as coarse aggregate: <ol> <li>new clean recycled concrete aggregate (NC-RCA) obtained by crushing the excess concrete returned to the ready mix yard; </li> <li>old de-icing salt contaminated, recycled concrete aggregate ( OC-RCA) from a demolished bridge over Highway 401 in Ontario; </li> <li>natural aggregate as a control material. </li> </ol> These three materials were crushed and sieved to give the same grading for each mix. Natural sand was used as fine aggregate. The mixes were adjusted to account for the different water absorption characteristics of the aggregates but were otherwise identical. Prism specimens with a centrally placed reinforcing bar, cylindrical specimens and non-reinforced slabs were cast from each of the concretes. After curing, the reinforced prisms were exposed to a saturated de-icing salt solution for two of every four weeks. For the second two week period, they were allowed to dry in the laboratory atmosphere or, to accelerate the process, dried at 32°C in a low humidity (18%) chamber. <br /><br /> The electrochemical corrosion behaviour of the steel was monitored using linear polarization resistance and cyclic polarization techniques. In addition, the physical properties of the materials were assessed. For the aggregates, water absorption, chloride content and susceptibility to abrasion were determined. For the concretes, compressive strength, salt scaling resistance and chloride permeability were measured and microscopic observation of the interfacial zones between the aggregate and the new cement paste were conducted. <br /><br /> On the basis of the results, it is concluded that the durability and the strength of the RCA concrete is very dependent on the age of the RCA aggregate. Water and chloride permeability, and, salt scaling and reinforcing steel corrosion resistance of concrete made with a very well hardened old RCA were comparable with or better than those of in normal concrete. Concrete incorporating new RCA exhibited inferior properties and consequently, it is recommended that, the OC-RCA concrete can be used as a sustainable material in structural applications.

Hundreds of ready-mix concrete trucks are dispatched daily from ready-mix concrete plants. On average, a concrete truck has a carrying capacity ranging from 7 to 9 cubic metres of concrete, requiring about 1500 litres of water. In addition, 500 to 1300 litres of water are used to wash out the excess concrete when the truck returns. Based on these figures, it is clear that the ready-mixed concrete industry consumes large amounts of fresh water. The purpose of this study is to determine the feasibility of using the wash water as mixing water in new concrete. The specific goal of this project is to determine the influence of the high pH and dissolved solids content of the wash water on the durability of concrete, particularly with respect to de-icing salt induced corrosion of steel reinforcement. Two types of mix designs were used in this research: a standard class N and a higher strength, structural C2 concrete. Two sets of concretes specimens were made with both mix designs: one with wash water and one with clean water. The project consists of a multi-component experimental program, beginning with wash water characterization, then pore solution and cement chemistry, followed by an evaluation of the effect of wash water on concrete workability and mechanical properties, resistance to de-icing salt scaling, and corrosion of reinforcing steel embedded in the concrete. In addition, the effect of the wash water on the effectiveness of air entraining agents (AEA) is being determined using air void analysis of specimens with different AEA contents. On the basis of the results obtained from the comparative study using wash water versus tap water, it appears that wash water can be used as mixing water for the production of concrete without compromising the durability properties related to corrosion and salt scaling performance. In addition, the mechanical and plastic properties of wash water concrete meet all standards pertaining to the use of wash water concrete and are similar to those of tap water concrete. Finally, the pore solution, thermal analyses, and water analyses of wash water and tap water showed comparable results. Overall, with regards to the tests conducted thus far, the use of wash water as mixing water in concrete poses no durability concerns.

Highway air pollution is a significant environmental threat that has staggering implications for human health worldwide. Photocatalytic materials have the potential to reduce air pollution levels near major highways using ultraviolet radiation. This project, funded by the Texas Department of Transportation, evaluated photocatalytic efficiency and durability of several commercially-available photocatalytic coatings for use on concrete structures near highways. The research presented in this thesis involved obtaining concrete highway barriers and creating concrete slabs for outdoor testing and laboratory chamber testing. Three commercially-available coatings were applied to the specimens for testing: Keim Soldalit ME paint, TxActive Stucco Cement, and Pureti Clean. Field sites were set up near major highways in Houston and Austin, Texas. Durability and photocatalytic efficiency were regularly monitored at the field sites using ion chromatography and spectrophotometry. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were conducted on samples from each of the specimens taken before and after placement at the field sites in order to understand durability of the photocatalytic materials that were exposed outdoors. SEM results from this research project revealed that the photocatalytic material in the TxActive stucco and Keim paint remained in their original distribution after the exposure period, while the photocatalytic material in the Pureti Clean product appeared to decrease. XRD results remained fundamentally consistent for all coatings. Ion chromatography results showed that TxActive specimens had the highest surface levels of nitrates and nitrites between rainfall events, which indicates photocatalytic activity. Spectrophotometry results revealed a decrease in brightness for the Keim paint-coated specimens and no change or an increase in brightness for the TxActive stucco over time. The spectrophotometry results indicate how many surface contaminants are accumulating on the surface of a specimen, and thereby how efficiently sunlight is reaching the surface and activating the photocatalytic process. Results obtained from this research project may be influential in the selection of a means for reducing highway pollution in Texas. / text

Introduction: Dolomite AB was in need of a dummy arm for crutch testing, to complement their existing test capabilities. Background: A large number of people need crutches on a daily basis. For them it is essential that their crutches do not fail. ISO (the International Organization for Standardization) conducts ongoing work to guarantee the durability and function of e.g. crutches. ISO has recently adopted a new standard for testing if elbow crutches. This has already met resistance, it has been claimed that the tests in it should include loading of the crutch in the frontal plane. Aim: To enable Dolomite to test elbow crutches in accordance with guidelines in ISO/FDIS 11334-1. And examine the magnitude of loads on a crutch in the horizontal- sagittal- and frontal plane. This to see if loading of the crutch in the fontal plane should be included in a new ISO-test. Goal: To fabricate a dummy arm for testing of elbow crutches. To gain knowledge of the magnitude of the load a crutch is subject to in the horizontal-, sagittal-, and frontal plane. Method: A dummy arm was made using methods and tools described in DPD (dynamic product development), and conventional fabrication methods. A test equipment was made, which registered the loads on a crutch, in three directions. Eleven persons, constituted the test group, one was excluded. Result: A fully functional dummy arm was manufactured. The average maximum load for the ten test subjects was: 33 kilos downwards, 12 kilos backwards and 2 kilos side wards. Discussion: The choice of materials was influenced by the strength demands, ease of manipulation, access and price. Dummy arm design was mostly a question of durability and function. The test group was made up of persons available when the test was done The crutch loading test indicates that the forces applied to a crutch In the frontal plane are small, compared to forces in the horizontal- and sagittal plane, almost negligible. Conclusion: A fully functional dummy arm was fabricated, no need for a new ISO-test for standard crutches was identified.