Expansion or swelling behavior of expansive soil has always created problems in the field of geotechnical engineering. When any construction has been carried out on expansive soil without pre-knowledge of their properties under various environmental conditions, the damage is severe. One of the methods to find out swelling potential of expansive soil is the expansive index (EI). The present study investigates the reduction of EI for the two commercially available expansive soils i.e., kaolinite and bentonite when mixed with Ottawa sand and Class C fly ash. The percentages of Ottawa sand and Class C fly ash mixed with kaolinite and bentonite were 0 to 50% by weight. The results show that there is a significant reduction in the swelling properties of expansive soil with the addition of Ottawa sand and Class C fly ash. The reduction in expansive index ranged approximately from 10 to 50% and 4 to 49% for kaolinite and bentonite, respectively. Also the maximum swelling pressure of kaolinite and bentonite soil decreased approximately 93% and 64%, respectively with the addition of various percentages of Ottawa sand and Class C fly ash. These results help to identify the swelling potential and swelling pressure of expansive soil with different percentages of sand and fly ash which will be beneficial to the geotechnical engineer. Standard index properties test such as liquid limit, plastic limit and shrinkage limit test was conducted to see the characteristic of expansive soil when mixed with less expansive sand and Class C fly ash. Also, for these expansive soils one dimensional (1-D) consolidation characteristics was studied with sand and Class C fly ash mixtures and the results were compared with pure kaolinite and bentonite soil. Pre-consolidation (Pc) behavior, compression index (Cc) and recompression or swelling index (Cs) properties were also studied for the different percentages of sand and Class C fly ash with expansive soil.

The Diploma´s thesis deals with the issue of comparison of recultivated areas and areas in the point of ecological succession from the viewpoint of the plant diversity of chosen hydro-ecosystems of Trebon basin, in the area of Suchdol nad Lužnicí. Mapped sandpits Cep, Cep I, Tušť a Františkov are situated in the flood plain of the river Lužnice. Local mining of sandy gravel started in 1950s and in some areas it has not finished until now. Every mining process leads to extensive damages of the landscape, which should be corrected. The aim of this thesis is to map and compare the areas on the coast of extracted sandpits where the recultivation was done with those which were left to "controlled" ecological succession.

abstract: ABSTRACT The Spirit landing site in Gusev Crater has been imaged by the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE) camera more than thirty times since 2006. The breadth of this image set allowed a study of changes to surface features, covering four Mars years. Small fields of bedforms comprised of dark material, and dark dust devil tracks are among the features revealed in the images. The bedforms are constrained within craters on the plains, and unconstrained in depressions less than 200m wide within the topography of the Columbia Hills, a ~120m-high structure in center of Gusev. Dust devil tracks appear in many images of the bedforms. Within the Columbia Hills, three bedform fields approximately 180m2 and composed of fine dark basaltic sand were studied, using five HiRISE images taken from 2006 to 2014. Both bedform crests and the dust devil tracks superimposed on them were evaluated for change to azimuth and length, and for correlation between the features. The linear to slightly sinuous transverse crests ranging from less than 1m to 113m in length and two to three meters in wavelength, are primary bedforms. During the study they shifted as much as 33 degrees in azimuth, and individual crests moved on the surface as much as 0.75m. The greatest changes corresponded to a global dust storm in 2007. Average crest movement was documented at the rate of 0.25m per year. Rather than moving progressively, the crests eventually returned to near their original orientation after the storm. The dust devil tracks, reflecting a more complex wind regime, including vortex development during diurnal heating, maintained predominantly NW-SE orientations but also reflected the effects of the storm. The observed modifications were neither progressive, nor strictly seasonal. The apparent stability of the bedform geometry over four seasons supports the predictions of the Mars Regional Atmospheric Modeling System (MRAMS): low speed (1-7.5 ms-1), daily alternating winds of relatively equal force. Crest profiles were found to be nearly symmetrical, without slipfaces to indicate a preferential wind direction; this finding also is supported by the MRAMS model. / Dissertation/Thesis / Masters Thesis Geological Sciences 2016

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Departamento Nacional de ProduÃÃo Mineral / The natural sand used in civil construction has become scarce due to the exhaustion of natural reserves and environmental constraints imposed by the regulatory agencies. Consequently, the prices of those inputs are likely to increase, burdening the consumer. In search of alternatives, sustainable and economical, this study proposes characterize crushed sand from quarries in the Fortaleza metropolitan region (RMF) and evaluate its implementation, as fine aggregate, in conventional concrete, as a replacement for natural sand. The experimental study is divided into two stages. The first one is the characterization of the physical, chemical and petrographical properties of eight kinds of crushed sand from RMF through the grading, density, water absorption, pulverulent material content, bulk density, grain shape analysis, alkali-aggregate reaction, petrographic analysis, X-ray fluorescence spectrometry (XRF) and X-ray diffraction (XRD) tests. The second step is the properties evaluation of the concretes produced with crushed sand incorporation. The tool "design and analysis of experiments" was used. The crushed sands were rated into three groups and a representative sand for each group was used in the concrete production, where two independent factors (water/cement ratio and crushed sand replacement content) were determined by ranging in three levels each one of them. The measurement variables analyzed were the additive consumption, compressive strength, diametral tensile strength, shrinkage, water absorption, void ratios, density and natural carbonation. The results suggest the viability of using crushed sand to replace natural sand in conventional concrete by 75%, given that the workability can be achieved with the use of plasticizing additives, and in general, there is an increase in the compression resistance, reduced water absorption and void ratios, in other properties the crushed sand incorporation produces no significant effects, therefore their use is considered to be technically feasible. / A areia natural utilizada na construÃÃo civil tem se tornado escassa devido ao esgotamento de reservas naturais e Ãs restriÃÃes ambientais impostas pelos ÃrgÃos fiscalizadores. Por consequÃncia, os preÃos desse insumo tendem a aumentar, onerando o consumidor final. Em busca de alternativas, sustentÃveis e econÃmicas, propÃe-se neste estudo caracterizar areias de britagem provenientes de pedreiras da RegiÃo Metropolitana de Fortaleza (RMF) e avaliar sua aplicaÃÃo, como agregado miÃdo, em concreto convencional, em substituiÃÃo à areia natural. O trabalho experimental està dividido em duas etapas. A primeira à a caracterizaÃÃo das propriedades fÃsicas, quÃmicas e petrogrÃficas de oitos tipos de areia de britagem da RMF, atravÃs dos ensaios de granulometria, massa especÃfica, absorÃÃo de Ãgua, teor de material pulverulento, massa unitÃria, anÃlise de forma dos grÃos, reaÃÃo Ãlcali-agregado, anÃlise petrogrÃfica, espectometria de fluorescÃncia de raios X (FRX) e difraÃÃo de raios X (DRX). A segunda etapa à a avaliaÃÃo das propriedades dos concretos produzidos com a incorporaÃÃo de areia de britagem. Utilizou-se a ferramenta âplanejamento de experimentosâ. Classificou-se as areias de britagem em trÃs grupos, sendo utilizada uma areia representante para cada grupo na produÃÃo dos concretos, onde se determinou dois fatores independentes (relaÃÃo Ãgua/cimento e teor de substituiÃÃo de areia de britagem) variando em trÃs nÃveis cada. As variÃveis de resposta analisadas foram: consumo de aditivo, resistÃncia à compressÃo, resistÃncia à traÃÃo diametral, retraÃÃo por secagem, absorÃÃo de Ãgua, Ãndices de vazios, massa especÃfica e carbonataÃÃo natural. Os resultados apontam a viabilidade da utilizaÃÃo de areia de britagem em substituiÃÃo à areia natural em concretos convencionais em atà 75%, tendo em vista que a trabalhabilidade pode ser alcanÃada com a utilizaÃÃo de aditivos plastificantes, e de modo geral, observa-se um incremento na resistÃncia à compressÃo, reduÃÃo da absorÃÃo de Ãgua e Ãndices de vazios, nas demais propriedades a incorporaÃÃo de areia de britagem nÃo produz efeitos significativos, portanto, sua utilizaÃÃo à considerado tecnicamente viÃvel.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-06-06T17:10:34Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) 2012-Dissertacao-GustavoAlexandreSilva.pdf: 10928701 bytes, checksum: 44c2b4f22827eed6eae53c17ea822ea3 (MD5) / Made available in DSpace on 2017-06-06T17:10:35Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) 2012-Dissertacao-GustavoAlexandreSilva.pdf: 10928701 bytes, checksum: 44c2b4f22827eed6eae53c17ea822ea3 (MD5) Previous issue date: 2012 / O setor de agregados para a construção civil possui a parcela de insumos minerais mais consumidos e, consequentemente, os mais significativos em termos de quantidades produzidas no mundo. Apesar de serem abundantes e apresentarem baixo valor unitário, seu consumo é um importante indicador do perfil sócio-econômico de desenvolvimento de um país, estado ou região metropolitana. Este trabalho foi concebido no intuito de suprir a carência de informações e dados sobre o setor de agregados para construção civil na Região Metropolitana de Natal-RN (RMN), conforme sua geologia e os recursos minerais, modo de ocorrência, especificações dos materiais e dados econômicos. Formada por dez municípios, a RMN se apresenta como uma das regiões de maior dinamismo econômico-social do Estado. Em relação a sua urbanização, a diferença é visivel, uma vez que a população rural supera a população urbana em alguns municípios. Sua área abrange uma superfície de 2.807,54 km², isto corresponde a 5,3% do território estadual. Sua população, de acordo com o Censo Demográfico de 2010, atingiu 1.351.004 habitantes. Isso representa 42,6% da população do Rio Grande do Norte (3.168.133 habitantes), compreendendo uma taxa de crescimento no período 2000 – 2010 de 1,88% ao ano. O Produto Interno Bruto (PIB) da RMN teve um aumento consistente de 2003-2008. No entanto, sua constribuição para o PIB do Estado, cai em média 0,63% ao ano devido processo de interiorização do desenvolvimento que o Rio Grande do Norte vem passando nos últimos anos. Na abordagem da geologia optou-se pela discussão dos registros geológicos em termos de unidades pré-quaternárias (anteriores a 2 milhões de anos) e unidades quaternárias. As rochas britadas e os sedimentos como areias e cascalhos são os materiais naturais utilizados como agregados na construção civil. Enquanto os sedimentos são usados, geralmente, como encontrados na natureza, as rochas podem passar por processos de britagem e moagem para atingir as especificações granulométricas. Na data da consulta havia registrados no DNPM destinados a produção de areia e brita 57 processos e dentre os 10 municípios da RMN os que apresentaram maiores quantidades de processos minerários foram: São Gonçalo do Amarante (28%), Ceará - Mirim (19%) e Monte Alegre (19%). O método de lavra de areia comumente utilizado na RMN é o de dragagem em leito de rio ou cava submersa, já que cerca de 85% da produção são proveninetes de áreas localizadas nos leitos dos rios. Os 15% restantes vêm dos terraços denominados de depósitos eólicos, riachos de menor porte. No caso da explotação de Brita o método de lavra é a céu aberto. O consumo de brita da Grande Natal é suprido pela produção de unidades pertencentes a três grupos empresariais. A produção de brita para a Grande Natal, foi estimada em 1.570.140 m3 /ano ou 2.590.731 t/ano, enquanto que a ociosidade média das instalações de beneficiamento das unidades produtoras está próxima de 50%. Em 2011 a produção anual de areia para construção civil foi de 1.967.159 m³ ou 2.950.738 t. Os Preços médios de brita, pesquisados, variaram desde R$ 30,00/t (ROM) até R$ 58,00/t (nas casas de materiais de construção), já os de areia foi de R$ 7,00 /t (ROM) até R$ 20,00/t (no varejo). As reservas estimadas (medidas e indicadas) de agregados, considerando a produção consumida atualmente na RMN, são suficientes para atender a demanda projetada para os proximos 15 anos isto sem levar em conta as reservas inferidas que podem aumentar substancialmente este tempo. / The most widely used inputs in the construction aggregates sector in the world are the mineral. Despite their abundance and low unit value, their use is an important indicator of the socioeconomic profile of a country, state or metropolitan region. This paper aimed to provide information and data, which are scarce, on the construction aggregates segment in the Metropolitan Region of Natal – RN (RMN), considering its geology, mineral resources, mode of occurrence, material specifications and economic data. Formed by ten cities, the RMN is the State region with the greatest economic and social dynamics. Regarding its urbanization, the rural population exceeds the urban population in some cities. The RMN covers an area of 2.807,54 km², accounting for 5.3% of the state territory. According to Brazilian Census 2010, its population reached 1,351,004 inhabitants, which corresponds to 42.6% of the population of Rio Grande do Norte (3,168,133 inhabitants), and a growth rate in the 2000 – 2010 period of 1.88% per year. The Gross Domestic Product (GDP) of the RMN has increased consistently from 2003-2008. However, its contribution to the state GDP falls 0.63% on average per year due to the recent process of internal development in Rio Grande do Norte. Concerning the geological approach, we decided to focus on the pre-quaternary (< 2 million years ago) and quaternary geologic periods. The crushed rocks and sediments such as sand and gravel are natural materials used as aggregates in construction. As the sediments are used generally in their natural condition, the rocks may undergo crushing and grinding process to achieve the required specifications. On the date of the consultation there were 57 processes recorded at the DNPM for the production of sand and gravel. São Gonçalo do Amarante (28%), Ceará - Mirim (19%) and Monte Alegre (19%) were the RMN cities with the highest number of mineral processing activities. The sand mining method commonly used in the RMN concerns river bed dredging or digging trial pits, since 85% of the production comes from fields located in riverbeds. The remaining 15% come from terraces known as aeolian deposits, small streams. Regarding the exploitation of gravel, the open pit mining method is used. The consumption of gravel in the Grande Natal region is supplied by production units belonging to three business groups. The production of gravel in the Grande Natal region was estimated in 1,570,140 m3 /year or 2,590,731 t/year, while the average idleness of the processing facilities of the production units close to 50%. In 2011 the annual building and construction sand was 1,967,159 m³ or 2,950,738 t. The average prices of gravel found ranged from R$ 30,00/t (ROM) to R$ 58,00/t (in construction material shops). The average prices of sand, in turn, ranged from R$ 7,00 /t (ROM) to R$ 20,00/t (in retail stores). Given the current production rates of aggregates in the RMN, the estimated reserves (measured and indicated) are sufficient to meet the demand forecast for the next 15 years, without taking into consideration the inferred reserves that can substantially increase this period.

This thesis studies methane hydrate crystal formation and decomposition at 1.0, 4.0 and 7.0°C in a new apparatus. Hydrate was formed in the interstitial space of a variable volume bed of silica sand particles with an average diameter equal to 329μm (150 to 630μm range). The initial pressure inside the reactor was 8.0MPa for all the formation experiments. Three bed sizes were employed in order to observe the effects of the silica sand bed size on the rate of methane consumption (formation) and release (decomposition). The temperature at various locations inside the silica sand bed was measured with thermocouples during formation and decomposition experiments. For the decomposition experiments, two different methods were employed to dissociate the hydrate: thermal stimulation and depressurization. It was found that more than 74.0% of water conversion to hydrates was achieved in all hydrate formation experiments at 4.0°C and 1.0°C starting with a pressure of 8.0MPa. The dissociation of hydrate was found to occur in two stages when thermal stimulation was employed whereas three stages were found during depressurization. In both cases, the first stage was strongly affected by the changing bed size whereas it was not found to depend on the bed size afterwards. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

The Mars Science Laboratory Curiosity rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active Bagnold dune field. The Bagnold sands are rounded to subrounded, very fine to medium sized (similar to 45-500m) with 6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion. Nevertheless, Bagnold mineralogy and Rocknest mineralogy are similar with plagioclase, olivine, and pyroxenes in similar proportions comprising >90% of crystalline phases, along with a substantial amorphous component (35%15%). Yet Bagnold and Rocknest bulk chemistry differ. Bagnold sands are Si enriched relative to other soils at Gale crater, and H2O, S, and Cl are lower relative to all previously measured Martian soils and most Gale crater rocks. Mg, Ni, Fe, and Mn are enriched in the coarse-sieved fraction of Bagnold sands, corroborated by visible/near-infrared spectra that suggest enrichment of olivine. Collectively, patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in Martian soils: (1) amorphous components in the sand-sized fraction (represented by Bagnold) that are Si-enriched, hydroxylated alteration products and/or H2O- or OH-bearing impact or volcanic glasses and (2) amorphous components in the fine fraction (<40m; represented by Rocknest and other bright soils) that are Fe, S, and Cl enriched with low Si and adsorbed and structural H2O. Plain Language Summary The Bagnold dune field is an active sand field with moving dunes and sits between the landing site of the Curiosity rover and rocks of interest higher up on Mount Sharp. When passing through the dune field, we used all of Curiosity's instruments to measure the chemistry, mineralogy, and grain size of sands in the Bagnold dune field in order to figure out where they came from, how the sands are transported, and what volatile materials (like water) lie within Martian soils. We found that the Bagnold sand dunes are very well sorted; no dusty materials are found within them, in stark contrast to soils seen previously with Curiosity and with rovers at other landing sites. We found that the coarser sand grains are enriched in the volcanic minerals olivine and pyroxene, confirming a prediction from orbit that wind-related activity seems to concentrate these phases. We also found that the dunes were much lower in water and other volatile elements like sulfur and chlorine versus all previous Mars soils. Using a combination of the rover's sieving system and chemical measurement tools, we figured out that two types of materials host water. In the first type of material, common in these sands, water is low in abundance (similar to 1%), very tightly bound to the grains, and is not released until temperatures >200 degrees C. In the second type of material, water is higher in abundance (2%) and more easily released by heating. Sieved water-bearing fine materials may be a useful resource for human explorers.

This study explored the available adfreeze data published in literature and the techniques used to obtain it. Two methods were selected and modified to complete series of adfreeze bond test. A model pile pull-out method consisting of pulling a pile out a large specimen of soil was the first method used. The second method was modified from an interface shearing apparatus developed by Dr. Fakharian and Dr. Evgin at the University of Ottawa in 1996 and allowed preparing, freezing and testing the specimen in place. The material and soil tested for this study were provided by EXP Services Inc. The model pile, a galvanized HSS 114.3 x 8.6 section, is commonly used to install solar panels. Soil was taken from a future solar farm site in proximity to Cornwall, Ontario. The study had for objective to develop a low cost adfreeze laboratory testing method. Limitations of the technics and apparatus used were observed. While the results of a model pile pull-out test compared to previous data publish by Parameswaran (1978), the interface shear series of test presented more limitations. The interface shearing method has been previously study by Ladanyi and Thériault (1990). Issues with the interface shear method due to the water content of the soil as well as the range of normal stress applied to the specimen both during testing and freezing. The data obtained was inconclusive and the method will be studied in future research program. This studied approach the adfreeze testing with new improvement. The main contribution of this study is the data obtained by measuring and observing adfreeze of ice poor sand with varying water content. The measurements allowed to study the effect that increasing water content has on the interface bond strength. The modifications made to interface shear apparatus are also major new contribution provided by this research. The apparatus was converted in a small freezer chamber using insulation panel and vortex tubes. Which was used to freeze the specimen in the testing chamber and testing adfreeze in place without handling the shear box arrangement.

Ecological evaluation techniques have been used to classify or evaluate the relative conservation worthiness of a portion of the Eastern Cape coastal zone from Cannon Rocks to Port Alfred. A system-based approach, using a basic GIS, was used to compare three aspects of the coastal zone. Two existing planning documents (EMATEK/s Coastal Vegetation Importance Rating plan and CPA's Cape Coastal Conservation plan) were statistically compared - based primarily on the size and number of the landscape fragments (environmental criteria polygons). The resultant plan, an Intermediate Sensitivity Class map, was further integrated with the biophysical aspect of the coastal zone - coastal dunes. The final map is the product of these overlays to be used as a-working overlay for coastal zone decision-making. This is an Environmental Sensitivity map, which has no particular direct reference to any particular biophysical criteria, which categorizes the coastal zone according to the environmental sensitivity or conservation worthiness of the site. The categories are listed according to a sliding-scale of sensitivity or worthiness. There is, however, it strong association between the final map and the vegetation status of the coastline, as a direct result of the vegetation rating map and indirectly from the perception based coastal conservation plan. The formation of most assessment or evaluation plans are based on the vegetation status of the area. This map can be overlayed over the particular stretch of the coastline which it covers and the particular conservation status noted. There are numerous techniques available for assessment and evaluation each having their own specific merits and advantages. This plan, however, is a first attempt at integrating other specific plans into a single working document for the coastal zone manager.

Arbuscular mycorrhizas (AM) are mutually beneficial symbiotic associations between the roots of plants and certain Zygomycetous fungi. The role of AM fungi in coastal sand dunes has been explored in many parts of the world, though little work has been conducted in South African dune systems. This study aimed to investigate the presence and extent of mycorrhizal colonisation of a coastal sand dune in South Africa. The roots of five plant species (Scaevola plumieri, Arctotheca populifolia, Ipomoea pes-caprae, Ehrharta villosa and Chrysanthemoides monilifera) were sampled along a foredune profile at Old Woman's River in the Eastern Cape. These roots were assessed for the percentage mycorrhizal colonisation they supported. Spores extracted from the rhizosphere sand of each plant species were counted and identified to genus level. Results were related to seasonality and the position of the plants along the profile. All plant species were found to be mycorrhizal. Percentage colonisation ranged from 0-92%, depending on plant species and season. Mycorrhizal colonisation was generally highest in the winter months, and especially so in I pes-caprae and E. villosa. The extent of various mycorrhizal structures in root tissue varied between plant species. Spore numbers ranged from 0-48 spores 100g-1 sand with highest numbers occurring in winter. S. plumieri and A. populifolia were associated with greatest spore abundance. Four fungal genera (Glomus, Acaulospora, Scutellospora and Gigaspora) were identified. Distribution of these genera showed seasonal variations between plant species. A bioassay, using Sorghum, was conducted to test the inoculum potentials of sand from the Scaevola hummock and the IpomoealEhrharta dune. Highest percentage colonisation occurred in plants grown in the Scaevola sand, which also had the lowest root and shoot measurements. The bioassay confirmed that AM propagules are present and viable, even in the mobile sand of the foredune. This study showed that mycorrhizal colonisation and spore numbers varied seasonally, but that the extent of this was dependent on plant species. The position of plants along the foredune profile tended to be less important than plant species. It is thought that the growth cycle and rooting system of each plant species determines seasonal cycles and abundance of AM fungi. Variation within fungal populations probably also impacts on this. Knowledge of the presence and distribution of AM fungi in this system paves the way for more detailed studies which need to examine the role of these endophytes in South African sand dunes.