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Hózhó, A Rainbow Project for Healthy PeopleMelhem, Sari 27 September 2021 (has links)
This thesis thrives to promote community health and wellbeing through smart design, celebrating culture(s), and offering efficacious and real-world solutions to mitigate certain challenges arising from the imminent threat of climate change and the gradual depletion of our planet's natural resources. The projected building harnesses naturel forces, minimizes energy consumption, and uses natural/passive strategies like thermal mass and natural ventilation. Interior spaces enjoy an abundance of Natural lighting, biophilic attributes, and thera-serlized or uninterrupted views. It generates electrical energy due to adequate solar power and clear skies, especially in hot and arid climates like the proposed location of the project in Tuba City, AZ. In my proposal of a sustainable, community-focused, wellness center, this project will attempt to embrace diversity, celebrate the Navajos heritage through incorporating their belief system and culture into the genius Loci of the place, which will have a long-term healing effect on patients during their journey of recovery. The Navajo nation is a native American reservation and a self-governing community located in the southwest of the US between four states (UT, AZ, NM, CO). Since it's an Underserved, marginalized, and medically under-resourced community, the Navajo Nation was prone to COVID-19 onslaught in 2020, which resulted in substantial number of cases compared to other US states. / Master of Architecture / In Dec 2020, the World witnessed the first case of Coronavirus disease or COVID-19 in Wuhan, China. The disease has since spread rapidly worldwide, leading to an ongoing pandemic. Like many countries across the globe, the health system in the United States of America has to grabble with this deadly virus by inducing measures such as mask mandates and lockdowns in many US states. Unfortunately, and due to economic and social disparities, COVID-19 pandemic has brought injustice and inequity to the forefront of public health. Some communities were hit hard due to lack of emergency response, the availability of health professionals, and healthcare infrastructure. Tuba city, which is the Diné or the Navajo nation second-largest community in Coconino County, AZ, was majorly hit with COVID-19 resulting in a significant number of cases compared to other US cities. This project is a critical component of an emergency preparedness matrix that can firstly; help absorb the shock of such outbreaks by providing primary and outpatient services. Secondly; it offers community-focused and wellness service that can empower underserved, under-resourced and valuable communities like the Navajo Nation. This project is unique due to its inherited and embedded characteristics of bringing the Navajo tradition into the spirit of the building, by celebrating their culture making it a key component in a patent's healing process.
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Stabilised Rammed Earth For Walls : Materials, Compressive Strength And Elastic PropertiesKumar, Prasanna P 07 1900 (has links)
Rammed earth is a technique of forming in-situ structural wall elements using rigid formwork. Advantages of rammed earth walls include flexibility in plan form, scope for adjusting strength and wall thickness, variety of textural finishes, lower embodied carbon and energy, etc. There is a growing interest in the construction of rammed earth buildings in the recent past. Well focused comprehensive studies in understanding the structural performance of rammed earth structures are scanty. Clear-cut guidelines on selecting soil grading and soil characteristics, assessing strength of rammed earth walls, density strength relationships, limits on shrinkage, standardised testing procedures, behaviour of rammed earth walls under in-plane and out of plane loads, etc are the areas needing attention. The thesis attempts to address some of these aspects of cement stabilized rammed earth for structural walls.
Brief history and developments in rammed earth construction with illustrations of rammed earth buildings are presented. A review of the literature on rammed earth has been provided under two categories: (a) Unstabilised or pure rammed earth and (b) stabilised rammed earth. Review of the existing codes of practice on rammed earth has also been included. Summary of the literature on rammed earth along with points requiring attention for further R&D are discussed. Objectives and scope of the thesis are listed.
The thesis deals with an extensive experimentation on cement stabilised rammed earth (CSRE) specimens and walls. Four varieties of specimens (cylindrical, prisms, wallettes and full scale walls) were used in the experiments. A natural soil and its reconstituted variants were used in the experimental work. Details of the experimental programme, characteristics of raw materials used in the experimental investigations, methods of preparing different types of specimens and their testing procedures are discussed in detail.
Influence of soil grading, cement content, moulding water content, density and delayed compaction on compaction characteristics and strength of cement stabilised soil mixes were examined. Five different soil gradings with clay content ranging between 9 and 31.6% and three cement contents (5%, 8% and 12%) were considered. Effect of delayed compaction (time lag) on compaction characteristics and compressive strength of cement stabilised soils was examined by monitoring the results up to 10 hours of time lag. Influence of moulding water content and density on compressive strength and water absorption of cement stabilised soils was examined considering for a range of densities and water contents. The results indicate that (a) there is a considerable difference between dry and wet compressive strength of CSRE prisms, and the strength decreases as the moisture content at the time of testing increases, (b) wet strength is less than that of dry strength and the ratio between wet to dry strength depends upon the clay fraction of soil mix and cement content, (c) saturated moisture content depends upon the cement content and the clay content of the soil mix, (d) optimum clay percentage yielding maximum compressive strength is about 16%, (e) compressive strength of compacted cement stabilised soil increases with increase in density irrespective of cement content and moulding moisture content, and the strength increases by 300% for 20% increase in density from 15.70 kN/m3, (f) compressive strength of rammed earth is one - third higher than that of rammed earth brick masonry and (g) density decreases with increase in time lag and there is 50% decrease in strength with 10 hour time lag.
Stress-strain relationships and elastic properties of cement stabilised rammed earth are essential for the analysis of CSRE structural elements and understanding the structural behaviour of CSRE walls. Influence of soil composition, density, cement content and moisture on stress-strain relationships of CSRE was studied. Three different densities (15.7 – 19.62 kN/m3) and three cement percentages (5%, 8% and 12% by weight) were considered for CSRE. Stress-strain characteristics of CSRE and rammed earth brick masonry were compared. The results reveal that (a) in dry condition the post peak response shows considerable deformation (strain hardening type behaviour) beyond the peak stress and ultimate strain values at failure (dry state) are as high as 3.5%, which is unusual for brittle materials, (b) modulus for CSRE increases with increase in density as well as cement content and there is 1 to 3 times increase as the cement content changes from 5% to 12%. Similarly the modulus increases by 2.5 to 5 times as the dry density increases from 15.7 to 19.62 kN/m3 and (c) the modulus of CSRE and masonry in dry state are nearly equal, whereas in wet state masonry has 20% less modulus.
Compressive strength and behavior of storey height CSRE walls subjected to concentric compression was studied. The results of the wall strength were compared with those of wallette and prism strengths. The wall strength decreases with increase in slenderness ratio. There is nearly 30% reduction in strength as the height to thickness ratio increases from 4.65 to 19.74. It was attempted to calculate the ultimate compressive strength of CSRE walls using the tangent modulus theory. At higher slenderness ratios, there is a close agreement between the experimental and predicted values. The storey height walls show lateral deflections as the load approaches failure. The walls did not show visible buckling and the shear failure patterns indicate material failure. The shear failures noticed in the storey height walls resemble the shear failures of short height wallette specimens.
The thesis ends with a summary of the results with concluding remarks in the last chapter.
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