A aplicação do bambu como elemento estrutural é comum em muitos países da Ásia e da América do Sul, ainda que com diferentes metodologias construtivas. Apesar de algumas espécies, como a bambu Mosô (Phyllostachys Pubescens) utilizada neste trabalho, possuírem excelentes propriedades mecânicas, sua difusão como elemento construtivo esbarra na dificuldade de se conceber sistemas de ligação eficientes entre os elementos estruturais. Uma vez que as ligações são o ponto frágil da estrutura, o colapso da estrutura pode ocorrer com o elemento estrutural ainda intacto. Este trabalho buscou avaliar a influência do sistema de ligação no desempenho estrutural de treliças planas executadas com três diferentes sistemas de ligação, sujeitas a condições de carregamento semelhantes. Ao comparar as resistências obtidas em ensaios de caracterização: compressão (41 MPa), tração (146 MPa) e cisalhamento (10 MPa), com as tensões solicitantes nas barras das treliças no momento do colapso, verificou-se que as propriedades mecânicas do bambu foram subutilizadas, uma vez que o colapso das estruturas ensaiadas teve início invariavelmente nas ligações. / The use of bamboo as structural element is a reality in many countries in Asia and South America, even with different building methodologies. Although some bamboo species, as Moso (Phyllostachys Pubescens) have excellent mechanical properties, its diffusion as a building element conflicts with the difficulty on conceiving efficient connection systems between structural elements. Given that joints are the weak point of the structure, collapse may occur even when the structural element is intact. This research aimed to evaluate the influence of connection systems on the structural performance of plan trusses built with three different connection systems subjected to similar load conditions. By comparing the strengths obtained on the characterization tests of compression (41 MPa), tension (146 MPa) and shear (10 MPa) to the acting stresses on the truss bars in the moment of collapse, it was noted that bamboo mechanical properties were underused, once the collapse of the tested structures always started by the connections.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Conventional, advanced and fractionation pretreatment technologies were employed to recover and/or enhance the efficacy of the main constituents present in lignocellulosic biomass. Bamboo and triticale bran are novel feedstocks and hence their response towards treatment is unknown. Thus, to assist with the characterisation of these feedstock, in terms of the amount of sugar released during acid and enzymatic hydrolysis, use were made of conventional pretreatment technologies. Pretreatment involved the use of either the conventional single-stage dilute-acid or the conventional acid-catalysed steam-explosion process at times, temperatures and acid concentration ranging between 5 to 40 min, 120 to 214°C, and 0.002 to 0.055 (H3O+) gmol/L, respectively. For additional comparison, results were also obtained from an established feedstock namely sugarcane bagasse, by subjecting it to the single-stage dilute-acid process, at similar pretreatment conditions employed during the treatment of the other feedstocks. Sugarcane bagasse and bamboo, upon pretreatment and enzymatic hydrolysis, both yielded a similar combined sugar recovery yield of 78.0% and 81.2%, respectively. Alternatively, only 55.3% (w/w) of the total sugar content in triticale bran could be recovered. Triticale bran consists predominantly of hemicellulose which, compared to cellulose, the main constituent in sugarcane bagasse and bamboo, is more susceptible to degradation. Thus, to enhance the combined sugar recovery yield, it is recommended that triticale bran be treated at less severe pretreatment conditions, in order to preserve the hemicellulose. To further enhance the amount of sugar (i.e. cellulose and hemicellulose) that can be recovered from sugarcane bagasse, the use of a two- rather than one-stage dilute acid process was proposed. The single-stage dilute acid process, despite being the subject of many research efforts, failed to recover more than 83% (w/w) of the total sugar content in sugarcane bagasse. Following an extensive literature study, it was concluded that sugarcane bagasse comprises a hemicellulose and cellulose fraction which dictates the use of different pretreatment conditions in order to ensure their effective recovery. The use of a more advance two-step dilute acid process was therefore proposed as it allows for multiple-sets of pretreatment conditions which accommodate the requirements set forth by each of the polysaccharides present in sugarcane bagasse. With the assistance of response surface methodology, a 4.8% (w/w) improvement over the single-stage method was calculated for the two-stage process, by assuming both pretreatment technologies operated at optimum pretreatment conditions. This improvement, which is similar to the 7.7% (w/w) obtained with substrates other than sugarcane bagasse, was accredited to the use of multiple-sets of pretreatment conditions. Both low and high severity pretreatment conditions were applied to maximise the recovery of hemicellulose and cellulose, respectively. In the case of bamboo however, little can be gained by using the two- in lieu of the one-stage method, as similar pretreatment conditions are required to maximise both hemicellulose and cellulose recovery. Alternatively, a three- rather than a two-stage process needs to be applied, when treating triticale bran, to accommodate for an additional set of pretreatment conditions required to recover arabinan, a third polysaccharide. In order to realise the full potential of sugarcane bagasse, use was made of a fractionation method, which in addition to the recovery of polysaccharide (i.e. cellulose and hemicellulose), also allowed for the recovery of the polyphenolic content (i.e. lignin) thereof. Limited by the complexity of the fractionation process, sugarcane bagasse was selected as the preferred substrate to be subjected to fractionation, mainly because of its availability in the South African (established sugar milling industry), and ease of treatment using both conventional (e.g. single-stage) and advanced (e.g. two-stage) pretreatment technologies. A novel fractionation technology, involving the use of the ionic liquid 1-butyl-3- mehylimidazolium methyl sulphate ([BMiM]MeSO4), was devised to separate the main constituents of sugarcane bagasse. Although other ionic liquid fractionation examples also exist in literature, processes used caused production of multi-component product streams with 34% (w/w) of the original lignin and hemicellulose being recovered in the same product stream. Tests conducted during the present study confirmed these results and further indicated that the production of multi-constituent product streams could not be avoided by using acetone, an acetone-water mixture or a sodium hydroxide solution as the solvent in a subsequent solvent extraction step. Hence, to avoid the production of multi-component product streams, a hemicellulose pre-extraction step, comprising the single-stage dilute acid process, was introduced to extract and recover 75% (w/w) of the hemicellulose content. The remaining solid was subjected to ionic liquid treatment whereafter it was effectively separated into cellulose and lignin enriched product streams through solvent extraction. Up to 73% (w/w) of the original lignin and cellulose content was recovered using optimum operating conditions (120 min; 125°C). Comparison of the novel ionic liquid ([BMiM]MeSO4) with 1-ethyl-3-methylimidazolium acetate, an established ionic liquid, identified the former to be the superior delignification solvent whereas the latter contributed more towards the digestibility of the residual solids. In conclusion, methods for the effective recovery of polysaccharides and polyphenol units from established (i.e. sugarcane bagasse) and novel (i.e. bamboo, triticale bran) lignocellulosic feedstocks have been demonstrated through the application of conventional (single-stage), advanced (two-stage) and fractionation pretreatment technologies. Economic improvement is promised through the application of these constituents as they may serve as precursor chemicals for the production of value-added products that may replace the fuel and chemicals currently derived from fossil carbon resources. / AFRIKAANSE OPSOMMING: Konvensionele, gevorderde en fraksionering voorafbehandeling tegnologieë is gebruik om die herwinning en gebruiksaamheid van die hoofbestanddele wat in lignosellulose biomassa aanwesig is, te verbeter. Bamboes en tritikale semels is nuwe rou materiale en dus is hul reaksie op behandeling onbekend. Ten einde die karaktereienskappe van hierdie rou materiale, in terme van die hoeveelheid suiker wat gedurende die suur- en suiker ensimatiese-hidrolise vrygestel word, te bepaal, is gebruik gemaak van konvensionele voorbehandeling tegnologieë. Voorbehandeling behels die gebruik van óf die konvensionele enkelstadium vedunde-suur óf die konvensionele suur-gekataliseerde stoomontploffingsproses; by tye, temperature en suurladings wat wissel tusen 5 en 40 minute, 120 tot 214°C, en 0.002 tot 0.055 (H3O+)gmol/L, onderskeidelik. Vir verdere vergelykings is resultate vanaf ’n gevestigde rou materiaal, naamlik suikerriet reste, verkry, deur dit te onderwerp aan ’n enkelstadium verdunde suur proses met dieselfde voorbehandeling toestande wat gegeld het gedurende die behandeling van die ander roumateriale. Tydens voorbehandeling en ensimaties-hidrolise het suikerriet reste en bamboes ’n gelyke gekombineerde terugwinnings opbrengs van 78.0% en 81.2% suiker, onderskeidelik, gelewer. Daar kon egter net 55.3% (w/w) van die totale suikerinhoud van tritikale semels herwin word. Tritikale semels bestaan hoofsaaklik uit hemisellulose, wat meer vatbaar is vir degradasie ten opsigte van sellulose, die hoof bestanddeel van suikerriet reste en bamboes. Om dus die gekombineerde suikerherwinnings-opbrengs te verbeter, word daar voorgestel dat tritikale semels aan minder strawwe toestande onderwerp word, om sodoende die hemisellulose te bewaar. Om verder die hoeveelheid suiker (d.w.s glukose en xilose) wat vanuit suikerriet reste herwin kan word, te verbeter, is die gebruik van ’n twee- in plaas van ’n eenstadium verdunde suur proses, voorgestel. Die enkelstadium verdunde suur proses het, ten spyte daarvan dat dit al die onderwerp van verskillende navorsing projekte was, nie daarin geslaag om meer as 83% (w/w) van die totale suikerinhoud vanuit die suikerriet reste te herwin nie. Na ’n uitgebreide literatuurstudie is daar tot die slotsom gekom dat suikerriet reste bestaan uit ’n hemisellulose deel en ’n sellulose deel wat die gebruik van verskillende voorbehandeling toestande noodsaak, om sodoende effektiewe herwinning daarvan te verseker. Die aanwending van ’n meer gevorderde twee-stap verdunde suur proses is dus voorgestel, aangesien dit van veelvoudige-stelle voorbehandelings toestande, soos vereis deur die polisakkariedes in suikerriet reste, gebruik maak. Deur die toepassing van reaksie oppervlakte metodologie, is ’n 4.2% verbetering op die enkel-stadium metode vir die twee-stadium proses behaal deur aan te neem dat beide van hierdie prosesse, by optimum kondisies vir maksimale suiker herwinning, uitgevoer is. Hierdie verbetering is soortgelyk aan die 7.7% (w/w) verbetering wat voorheen met andersoortige substrate (uitgesonder suikerriet reste) verkry is. Sodanige verhoging word toegeskryf aan die gebruik van veelvoudige stelle van voorbehandeling toestande, wat beide meer en minder strawwe toestande insluit, om sodoende die herwinning van xilose en glukose onderskeidelik te maksimeer. In die geval van bamboes, is die twee-stadium metode nie superieur tot die een-stadium metode nie, aangesien soortgelyke voorbehandeling-toestande benodig word om beide die herwinning van xilose en glukose te maksimeer. Alternatiewelik moet ’n drie-stadium in plaas van ’n twee-stadium proses gebruik word wanneer tritikale semels behandel word aangesien ’n bykomende stel voorbehandeling toestande benodig word om arabinan, ’n derde polisakkaried, te herwin. Om sodoende die volle potensiaal van suikerriet reste te ontgin, is gebruik gemaak van ʼn fraksioneringstegnologie. Waar konvensionele voorbehandeling metodes slegs fokus op die herwinning van polisakkariedes (naamlik sellulose en hemisellulose), kan die fraksioneringsproses ook die poli-fenoliese inhoud (naamlik lignien) in lignosellulose, herwin. Weens die ingewikkeldheid van die fraksioneringsproses, is suikerriet reste gekies as die mees geskikte substraat vir fraksionering, hoofsaaklik omdat dit veral in die Suid- Afrikaanse konteks, maklik beskikbaar is en omdat dit ook maklik is om met beide die konvensionele (bv. die enkel-stadium) en die gevorderde (bv. die twee-stadium) voorbehandeling proses behandel te word. ʼn Nuut ontwikkelde fraksionering tegnologie wat gebruik maak van die ioniese vloeistof 1-butiel-3-metielimidazolium metielsulfaat ([BMiM]MeSO4) is ontwikkel, om die hoofbestanddele in suikerriet reste van mekaar te skei. Literatuur bevat verskeie voorbeelde waar ioniese vloeistowe gebruik word vir fraksionering. Die doeltreffendheid van hierdie prosesse is egter deur die produksie van multi-komponent produkstrome, waartydens tot en met ekwivalente hoeveelhede hemisellulose en lignien in dieselfde produkstrome herwin is, beperk. Hierdie resultate is tydens die studie deur middel van toetse bevestig. Sodanige toetse het ook aangedui dat die produksie van multi-komponent produkstrome nie deur die gebruikmaking van asetoon, ʼn asetoon-water mengsel of ʼn natrium hidroksied oplosmiddel, wat deel maak van ʼn opvolgende oplossing-ekstraksie-stap, vermy kon word nie. Om gevolglik die vervaardiging van multi-komponent produkstrome te vermy, is ʼn hemisellulose vooraf-ekstraksie stap, bestaande uit die enkel-stap verdunde suur proses, gebruik, om sodoende 75% (w/w) van die hemisellulose inhoud in suikerriet reste, te herwin. Die oorblywende vastestof was onderwerp aan ioniese vloeistof behandeling waarna dit effektiewelik geskei is in onderskeidelik, sellulose en lignien verrykte produkstrome, verkry deur gebruikmaking van ʼn oplossing-ekstraksie-stap. Tot en met 73% (w/w) van die oorspronklike lignien en sellulose inhoud was herwin deur gebruik te maak van optimale behandelingskondisies (120 min, 125°C). ʼn Vergelyking tussen die nuut-geïdentifiseerde ioniese vloeistof ([BMiM]MeSO4) en 1-etiel-3-metielimidazolium asetaat, ʼn gevestigde ioniese vloeistof, het aangetoon dat eersgenoemde ʼn superieure delignifikasie oplosmiddel is terwyl laasgenoemde ʼn groter bydra tot die verteerbarheid van die oorblywende reste lewer. Ten slotte het hierdie studie, metodes vir die effektiewe herwinning van polisakkariedes en poli-fenoliese eenhede, vanaf gevestigde (bv. Suikerriet reste) en nuwe (bv. bamboes en tritikale semels) lignosellulose rou materiale, gedemonstreer, deur telkens van konvensionele (enkel-stadium), gevorderde (twee-stadium) en fraksionerings voorbehandeling tegnologieë gebruik te maak. Ekonomiese verbetering kan dus verwag word indien hierdie bestanddele as voorloper chemikalieë vir die produksie van waarde toegevoegde produkte aangewend word, aangesien sodanige produkte die plek kan inneem van brandstof en chemikalieë wat tans vanuit fossielbronne vervaardig word.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly Waggle Kramer / This document addresses East Africa's need for safe, sustainable, and affordable housing and promotes use of bamboo as a structural material by providing adequate information and resources to evaluate the strength of bamboo. East African housing is a leading issue for the region because of the population growth, specifically in urban areas where housing resources and infrastructure cannot match the population growth. The solution may be bamboo housing as an alternative to urban slums. The bamboo species Oxytenanthera abyssinica is available throughout East Africa region and has been accepted and implemented in traditional housing throughout the region. This document references the resources provided by the International Code Council (ICC), International Organization for Standardizations (ISO), and International Network for Bamboo and Rattan (INBAR) for the use of bamboo as a structural material in buildings. This paper also discusses the mechanical strength of bamboo, and the structural behavior of bamboo in buildings. In addition, bamboo construction shows the tools, connections, and preservatives used in the field. The design example, using Oxytenanthera abyssinica, provides the traditional layout and materials for an Amhara house, and calculations show the practicality of bamboo in structural design. This document has led to recommendations for engineers and the bamboo industry, including the development of a codebook for bamboo design, promoting bamboo farms and plantations, creating a uniform connection, and increasing bamboo's service life. From research, bamboo is in need of further development before being considered a viable structural material to provide for commercial use but would suffice for the housing shortage in East Africa.

Ce travail a pour objectif l'adaptation en climat tropical d'une technique de phytoépuration utilisant le bambou pour le traitement des eaux usées, déjà développée en climat tempéré. L'étude porte sur la détermination de valeurs de référence pour plusieurs espèces de bambou tropicales (i) des capacités d'absorption d'eau, (ii) de production de biomasse aérienne, et (iii) d'absorption des nutriments. La démarche expérimentale a consisté, dans un premier temps, à déterminer la réponse morphologique de sept espèces de bambous, suite à l'apport excessif de nutriments, comme cela peut se produire lors de l'apport d'eaux usées. Dans un deuxième temps, les capacités d'évapotranspiration de cinq espèces de bambous ont été étudiées en cuves lysimètriques. Enfin, la production de biomasse, ainsi que les prélèvements en azote, phosphore et carbone d'un peuplement multispécifique ont été étudiés en réponse à l'apport de lisier, en conditions réelles d'une station pilote. Ces études ont montré que des apports excessifs en nutriments améliorent la croissance du bambou sans causer de stress détectable. Ils améliorent également la capacité photosynthétique des bambous, ainsi que la production de biomasse, qui est augmentée d'un facteur 2 à 6 selon les espèces, par rapport au traitement témoin. La production de biomasse importante, de l'ordre de 20,7 à 80 tonnes de matière sèche produite par hectare et par an, confère aux espèces étudiées des capacités d'extraction élevées, avec des exportations de 400 à 1600 kg.ha-1 en azote, 30 à 130 kg.ha-1 de phosphore et 18 à 67 t.ha-1 de carbone piégé dans la biomasse en deux ans. Les taux d'évapotranspiration des bambous sont plus élevés que ceux de cultures classiques, avec des valeurs moyennes annuelles comprises entre 4 et 7mm/j et des coefficients culturaux moyens de 2,1 à 3,8 selon les espèces. Cette étude a permis d'identifier plusieurs espèces de bambous intéressantes pour le traitement des eaux usées en climat tropical, notamment les espèces Bambusa oldhamii, Bambusa vulgaris et Gigantochloa wrayii. Dans une optique de phytoépuration ces résultats sont d'autant plus encourageants qu'ils ont été obtenus avec des plants de bambou n'ayant pas encore atteints leur pleine maturité. / The aim of this work was to adapt under tropical climate, a wastewater treatment phytotechnology which uses bamboo species, already developed under temperate climate. The objectives of the study were to establish reference values on the water and nutrient uptakes, and on above-ground biomass yields, for different tropical bamboo species. The experimental approach relied first in the quantification of the morphological response of seven bamboo species under high nutrient loads, up to 13.2 t.ha-1.yr-1 of NPK, as it occurs in wastewater treatment system. Second time, the evapotranspiration rates and crop coefficients of five bamboo species were determined using a lysimeter experiment. Finally, the biomass yield and the nitrogen, phosphorus and carbon uptakes were studied for a multi-specific bamboo plantation in response to pig slurry application, at field scale. The results have shown that the high nutrient load (13.2 t.ha-1.yr-1 of NPK) did not cause any detectable stress on the bamboo growth. On the contrary, the photosynthetic activity was improved and the growth rate was increased by 2 to 6 times compared with the control treatment. Depending on bamboo species, the annual biomass yield ranges from 20,7 to 80 t.ha-1.yr-1, and the nutrients storage into the biomass was 400 to 1600 kg.ha-1 for nitrogen, 30 to 130 kg.ha-1 for phosphorus and 18 to 67 t.ha-1 for carbon, in two years of experiment. The yearly average evapotranspiration rates were higher than for typical crops and range from 4 to 7mm.day-1, with average crop coefficients between 2.1 to 3.8, depending on species. Due to their high biomass yield, high nutrient uptakes and high evapotranspiration rates, some bamboo species, i.e. Bambusa oldhamii, Bambusa vulgaris and Gigantochloa wrayii appear as good candidates for wastewater treatment under tropical climate. These results are even more promising since they were obtained for non mature bamboo plants.

Visando o desenvolvimento de materiais biodegradáveis para embalagens, blendas de amido/quitosana estruturadas com nanopartículas de montmorilonita (MMT) ou nanofibras de bambu (NFBs) em concentrações de (0,0; 0,5 e 1,0) g de NPs/100 g de polímero foram obtidas pelas técnicas de casting e extrusão. Os bionanocompósitos obtidos das duas técnicas foram caracterizados, bem como foi avaliada a influência da dispersão das nanopartículas sobre as principais propriedades físico-químicas dos bionanocompósitos. Para os filmes produzidos de blendas de amido/quitosana por casting, foram avaliadas as proporções de (5/0; 3,75/0,25; 2,5/2,5; 1,25/0,75 e 0/1) g/100 g base polímero, e a adição dos reforçadores na solução filmogênica. Observou-se uma dispersão assim como uma intercalação satisfatória da MMT nos bionanocompósitos, confirmadas pelas mudanças da cristalinidade devido ao deslocamento do pico característico de 7,2 º para 5,2 º; e os filmes estruturados com NFBs apresentaram variações nas frequências vibracionais dos arranjos moleculares indicando a formação de ligações fortes entre as blendas e os reforçadores. A partir da extrusão da mistura de homo pellets e pellets masterbatch, das blendas de amido/quitosana nas proporções de (100/0; 75/25 e 50/50) g/100 g, foram obtidos compósitos em processo contínuo os quais exibiram propriedades qualitativas satisfatórias assim como mudanças de cristalinidade e interações moleculares. Em relação às propriedades mecânicas, os bionanocompósitos apresentaram um aumento da resposta à tensão assim como da elongação e módulo de elasticidade em relação às concentrações dos reforçadores em cada umas blendas avaliadas. Por outro lado, tanto a formação das blendas como as interações dos reforçadores modificaram significativamente a rede tridimensional dos filmes em relação à taxa de transferência de vapor de água, obtendo-se valores de (155 e 139) g m-2 d-1 para os compósitos obtidos da blenda amido/quitosana 100/0 estruturados com (0,5 e 1,0) g MMT/100 g, respectivamente. Os valores de PVA obtidos são inferiores aos reportados por produtos comerciais como o (PBS) Bionolle™ (330 g m-2 d-1) e (PBAT) Ecoflex® (272 g m-2 d-1). Neste trabalho foi possível desenvolver um material promissor com características diferenciadas e alta aplicabilidade no setor de embalagens biodegradáveis para uso industrial. / Aiming at the development of biodegradable packaging materials, starch/chitosan blends structured with montmorillonite nanoparticles (MMT) or bamboo nanofibers (NFBs) at concentrations of (0.0,0.5 and 1.0) g NPs/100 g of polymer were obtained by the casting and extrusion techniques. The obtained bio-nanocomposites were characterized, as well as, how the dispersion of nanoparticles influenced the main physicochemical properties of the films. For the films from starch/chitosan blends produced by the casting method, the proportions of (5/0, 3.75/0.25, 2.5/2.5, 1.25/0.75 and 0/1) g/100 g based on polymer, were tested and the introducing of the reinforcers into filmogenic solution were evaluated. Satisfactory dispersion and exfoliation of MMT in bio-nanocomposites were confirmed by changes of crystallinity due to displacement of the characteristic peak from 7.2 ° to 5.2 °. In the same way, films structured with NFBs showed variations of the vibrational frequencies of the molecular arrangements indicating strong bonds between the polymer blends and the reinforcers. By the extrusion from the mixture of homo pellets and masterbatch pellets, from starch/chitosan blends at proportions of (100/0, 75/25 and 50/50) g/100 g, the obtained films have exhibited changes of the crystallinity and the molecular interactions. In relation to mechanical properties, the films presented increase of the tension response as well as the elongation and modulus of elasticity in relation to the reinforcer concentration in each evaluated blend. On the other hand, the formation of polymer blends and the interactions of reinforcers with the matrix changed significantly the three-dimensional network and consequently the water vapor transmission (WVT). Films produced from starch/chitosan 100/0, nanostructured with (0.5 and 1.0) g MMT/100 g, exhibited lower values of WVT 155 e 139) gm-2 d -1, respectively, when compared to commercial products such as Bionolle ™ (PBS) 330 g m-2 d-1) and (PBAT) Ecoflex® (272 g m-2 d-1). In this work, it was possible to develop a promising material with desired characteristics in the biodegradable packaging sector with wide application in the industry.

No Contínuo de Paranapiacaba, remanescente representativo do bioma Mata Atlântica formado pelos Parques Estaduais Intervales, Carlos Botelho e Alto Ribeira e a Estação Ecológica de Xitué, florestas com ocorrência dominante de bambus são, atualmente, integrantes da paisagem, perfazendo extensa área dessas Unidades de Conservação do sul do Estado de São Paulo. Este trabalho teve como proposta descrever o cenário dessas florestas com bambus, a partir da análise dos padrões e condicionantes dessa paisagem no Parque Estadual Intervales (PEI). O trabalho partiu da hipótese de que a ocorrência dominante dessas áreas com bambu seja conseqüência de perturbações históricas. A análise temporal de fotos aéreas recobrindo o período de 1960 a 2000, apresentado no Capítulo 2, possibilitou espacializar e caracterizar os diferentes processos de ocupação no Parque, com a dinâmica da paisagem sendo associada a dois principais vetores de perturbação, atividades de roça e exploração de palmito juçara (Euterpe edulis), que ocorreram de forma desordenada, intensa e recorrente na extensa área entre a Sede e as bases Carmo e São Pedro. A partir da caracterização da vegetação discutida no Capítulo 3, os padrões da paisagem atual do PEI foram associados, fundamentalmente, às áreas florestais sem e com ocorrência dominante de bambus das espécies Guadua tagoara (Nees) Kunth, Chusquea oxylepis (Hack.) Ekman, Chusquea sp. e Merostachys sp., que interferem na estrutura florestal. Os padrões da paisagem relacionados à ocorrência dominante, dinâmica e histórias de vida das diferentes espécies de bambus refletem nos padrões identificados na imagem QuickBird no Capítulo 4, possibilitando delimitar grandes clareiras ocupadas por populações de bambus internamente sincronizadas. A relação dessa dominância de bambus e alguns fatores naturais e antrópicos foram abordados no Capítulo 5, com os resultados direcionando para o modelo de que o evento de dominância por bambus é potencializado por perturbações naturais e/ou antrópicas, e quando estabelecidos, os bambus tornam-se o próprio agente de perturbação do ecossistema, resultando em uma possível homogeneização permanente da paisagem. A integração de informações nas diversas escalas de observação permitiu o entendimento do contexto dessa floresta com bambu, evidenciando a necessidade de escalas adequadas aos estudos nessa paisagem. Na escala local, considerando os indivíduos e populações, foi possível a caracterização das fenofases, principalmente dos ciclos reprodutivos maciços e processos de regeneração das espécies dominantes. Na escala de comunidade observaram-se as interações entre as espécies de bambus, com a ocorrência associada e sobreposição dos ciclos reprodutivos de algumas delas, e a interferência na estrutura da floresta. Na escala de paisagem, os padrões de população e comunidade de bambus foram identificados nas imagens, permitindo discutir esse padrão de dominância em relação a outras áreas com bambus, ainda que em fisionomias florestais distintas. Os resultados encontrados contribuem para o entendimento da dinâmica da floresta com bambus do Contínuo de Paranapiacaba, possibilitando definir indicadores do processo de dominância, fundamentais para a gestão desse remanescente de Mata Atlântica. / The so-called region \"Continuous from Paranapiacaba\", a representative remnant of the Atlantic Forest, is constituted by São Paulo State Parks Intervales (PEI), Carlos Botelho, Alto Ribeira and Ecological Station of Xitué. These forests that have dominant bamboo occurrences, are presently integrating the landscape at large sections within these conservation units in the southern São Paulo State. The objective of this work is to describe the scenery of such forests from the analysis of patterns and conditioning factors of the landscape at PEI. As a working hypothesis, it was assumed that the dominant occurrence of bamboo is a consequence of historical perturbations. The temporal analysis of aerial photographs covering the timeframe 1960 to 2000 presented at Chapter 2 allowed the mapping and characterization of the different processes of land occupation within the park. The landscape dynamics is associated to two main types of perturbation factors, namely to small-scale clear-cutting and to the exploitation of palm tree Euterpe edulis, which occurs disorderly, intensely and recurrently at the extensive area between the administration office and the bases of Carmo and São Pedro. From the characterization of vegetation, discussed at Chapter 3, the present landscape patterns of PEI were associated to forest areas with and without dominant occurrences of bamboo from species Guadua tagoara, Chusquea oxylepis, Chusquea sp. and Merostachys sp., which interfere at the forest structure. The landscape patterns related to the dominant and dynamic occurrence and to the histories of life from the different species of bamboo can be seen at the different patterns identified on the QuickBird image presented at Chapter 4, allowing mapping of the large clearings occupied by populations of bamboos internally synchronized. The relation between this dominance of bamboos with some natural and human factors is presented at Chapter 5 and the results are directed towards the model that the dominance event is increased by natural or human perturbations, and when bamboos are established they are themselves the perturbation agent of the ecosystem, resulting in a possible permanent homogenization of the landscape. The integration of information from different scales of observation allows the understanding of the context from this bamboo forest, evidencing the need of adequate scales to study these landscapes. At the local scale, considering the individuals and populations, it was possible to characterize the phenological phases, especially of the massive reproduction cycles and of the recovery processes of dominant species. At the scale of community, one can observe the interactions between bamboo species with the associated occurrence and superposition of reproductive cycles of some of these species, and its interference at the forest structure. At the landscape scale, the population patterns and communities of bamboos were identified at the images, permitting the discussion of this dominance pattern in relation to other areas with bamboo, but at distinct forest physiognomies. The results found in this study contribute to understand the bamboo forest dynamics of this region, permitting the definition of indicators from the dominance process, of importance for the management of this remnant from the Atlantic Forest.

O foco desta pesquisa é o estudo do desempenho de colmos de bambu em estruturas de cobertura. A arquitetura do século XXI precisa de novos modelos de produção e novos materiais para possibilitar o desenvolvimento sustentável do planeta. O bambu é um material renovável, com custos de produção baixo, pegada ecológica positiva e de qualidade física excelente; mas existe um desconhecimento bastante generalizado sobre o seu uso na construção civil. Esta lacuna é ainda maior quando se procura entender seu comportamento estrutural ao longo do tempo. Entre os vários requisitos para avaliar o desempenho do material, quando é o elemento portante de uma construção, destacam-se dois que são essenciais: a estabilidade e a durabilidade. Neste trabalho procura-se, em primeiro lugar, compreender o comportamento físico-mecânico do material na composição microscópica e macroscópica para delimitar sua segurança estrutural, e em segundo lugar, examinar aqueles processos que, desde o crescimento da planta até à sua utilização em obra, determinam a vida útil do material. São também analisadas as práticas construtivas e ações de projeto que condicionam transversalmente estas duas exigências de desempenho, junto com um levantamento de estudos de caso que visa criar novos critérios de design de estruturas e soluções construtivas. Esta pesquisa procura expor os pontos fortes e fracos da atual construção com bambu, para que os primeiros sejam potencializados e os segundos sejam corrigidos. / The focus of this research is the study of the performance of bamboo in coverage structures. The architecture of the 21st century needs new production models and new materials to enable the sustainable development of the planet. Bamboo is a renewable material, with low production costs, positive ecological footprint and excellent physical-mechanical properties; but there is a rather general lack of knowledge about its use in civil construction. This gap is even greater when one tries to understand its structural behaviour over time. Among the various requirements to evaluate the performance of the material, when it is the structural element in a construction, two that stand out are essential: stability and durability. In this work, the understanding of the physical and mechanical behaviour of the material in the microscopic and macroscopic composition is sought first to delimit its structural safety, and secondly, examining the processes that, since the plants\'s growth until its usage in work, determine the useful life of the material. It is also analyzed the constructive practices and project actions that condition transversally these two performance requirements, along with a survey of case studies that aim to create new criteria of structure design and building solutions. This research seeks to export the strengths and weaknesses of the current construction with bamboo, so the first may be potentialized and the latter corrected.

No presente trabalho avaliou-se a resistência mecânica do bambu nos estágios pré e pós processamento mecânico para servir de referências básicas do estudo das propriedades mecânicas de vigas laminadas coladas simples, de seção composta e de seção composta na forma de I, industrializadas em laboratório. Iniciou-se com a caracterização do material bruto na forma de ripa que representa toda a parede do colmo, passando-se pelo material processado na forma de lâmina que representam a parte industrialmente útil da parede do colmo e culminando na manufatura e qualificação das vigas laminadas coladas. Na produção dos corpos de prova do material bruto manteve-se a espessura original da ripa, exceto para alguns produzidos para se avaliar a resistência ao cisalhamento radial das camadas interna e externa da parede do colmo. As ripas foram usinadas em diversas máquinas para serem transformadas em lâminas que são as unidades de composição das seções compostas pela técnica de aglutinação e adesão a frio. Foi estudada também a influência do nó na resistência ao cisalhamento radial e tangencial tanto do material sólido quanto do plano de cola e nas propriedades da flexão. A geometria e as dimensões dos corpos de prova de cisalhamento foram adaptadas da norma ASTM D 905 e os de flexão da norma NBR 7190. As resistências ao cisalhamento no plano de cola e as propriedade da flexão foram determinadas segundo três combinações de faces de contato no processo de colagem com o adesivo à base de resorcinolformaldeído (RF). Estudou-se também a pressão adequada para colagem dos corpos de prova e eleita a mais adequada à colagem de vigas laminadas coladas. Os corpos de prova intactos e rompidos nos ensaios foram observados em microscópio eletrônico de varredura, em microscópio óptico, em microscópio óptico de fluorescência e microscópio estereoscópico. Observou-se ampla variabilidade das propriedades mecânicas tanto do material sólido quanto do material composto, mas em qualquer dos casos de resistência houve ampla variabilidade dos dados e, no geral o material sem nó foi mais resistente do que o com nó. As rupturas ocorreram na maioria das vezes no tecido parenquimático desviando-se dos feixes de fibras e tendendo a seguir a grã do material observando que o plano de ruptura só coincide com o plano planejado para a ruptura quando o corpo de prova é feito com a consideração precisa da orientação da grã. Os corpos de prova montados com a cola à base de PVA e com lâminas nodais responderam de forma satisfatória à colagem a baixa pressão, enquanto que os fabricados com lâminas internodais apresentaram melhor desempenho a alta pressão. Para os corpos de prova manufaturados com o adesivo à base de RF, a melhor combinação de colagem se deu no contato entre faces externas de lâminas. Foi possível observar a penetração do adesivo nos elementos anatômicos das lâminas com o uso da microscopia óptica e de fluorescência. As vigas laminadas coladas de seção transversal composta foram ensaiadas à flexão, mas não romperam por tensão normal, pois apresentaram instabilidade lateral durante o carregamento à flexão. As vigas também apresentaram baixo módulo de elasticidade porque o esmagamento da mesa inferior, nos apoios, foi cofundida e somada pelo sistema de medida, ao valor da flecha. Numa análise geral, a qualidade mecânica da Viga \"I\" pode ser considerada muito boa dentro do correto cálculo do momento de inércia se seções transversais compostas. As camadas perpendiculares ao eixo da via, tanto na alma quanto na mesa, foram tão eficientes na absorção do esforço cortante que não houve nenhuma limitação de capacidade de carga pela ligação alma-mesa mesmo com a viga trabalhando numa faixa de alta influência de tensões cisalhantes. / In this study it was evaluated the bamboo strength in the stages before and after mechanical processing in order to obtain basic references to study the mechanical properties of simple glued laminated beams of composite section and composed section as I joist, manufactured in laboratory scale. It started with the characterization of raw material as strip representing the crude bamboo culm wall, moved to the processed material as in the shape of laminas which were representing the majority of bamboo culm wall industrially useful and culminating to the manufacture and qualification of glued laminated beams. In the production of specimens of raw material it was maintained the original thickness for the strip except for a few ones which were produced to evaluate the radial shear strength in the inner and outer layers of the culm wall. The strips were machined on some machines to be turned into laminas that were the units for assembling composite sections by agglutination and adhesion under pressure in environmental conditions. It was also studied the node influence in the radial and tangential shear strength in both solid material and in the adhesive plan and in properties got from the bending tests. The geometry and dimensions of the shear specimens were adapted from ASTM D 905 and the bending from NBR 7190. Shear strength in the adhesive plane and bending property were determined following three combinations of contact faces on the gluing process using resorcinol-formaldehyde based adhesive. It was studied also the proper pressure for gluing the specimens and elect the most suitable for glued laminated beams. The intact specimens and failed on mechanical tests were observed under a Scanning Electron Microscope, Optical Microscope, Optical fluorescence microscope and stereomicroscope. It was observed huge variation of mechanical properties in both solid and composite materials, but in all cases there was considerable variability of strength data and in general the material without node was more resistant than with node. The ruptures mechanisms occurred most often in the parenchyma tissue by passing the fiber bundles and tend to follow the grain of the material by observing the rupture plane that only coincides with the plan designed to rupture when the specimen is done with precise consideration of grain orientation. The specimens manufactured with PVA adhesive and components with nodes responded satisfactorily to the low pressure bonding, while the specimens produced with internodes components performed better at high pressure. For specimens manufactured with resorcinol-formaldehyde adhesive the best gluing combination was given by the contact of outer laminas surfaces to each other. It was possible to observe the anchorage of the adhesive into the anatomical tissues by using optical microscopy and fluorescence optical microscopy. Glued laminated beams with composite cross section were tested in bending, but not failed by normal stresses, once there occurred only lateral instability during loading time. The I beams also showed low modulus of elasticity because the crush in the inferior flange was added by the measurement system to the bending deflection. In general the mechanical quality of the \"I\" joist can be considered very high with correct calculation of the moment of inertia of composite cross sections. The layers perpendicular to the beam axis both in web and in the flanges, were so efficient in absorbing the shear that there was no limitation of carrying load web-frange connection even with the beam working in a critical influence of high shear stresses.

O presente estudo teve como objetivo avaliar e comparar os processos de polpação kraft convencional e SuperBatchTM para Bambusa vulgaris visando a produção de polpa celulósica não branqueável (número kappa 58±2). A matéria prima foi caracterizada com relação à densidade básica, composição química e dimensões de fibras; foi realizado um estudo de pré-extração aquosa com as temperaturas de 50, 70 e 90°C durante 5 horas pesando-se os cavacos a cada 15 minutos para avaliar a absorção de água. Este mesmo procedimento foi feito à temperatura de 110°C com tempos de 15 minutos, 1, 2 e 5. Posteriormente foram avaliados os teores de extrativos totais e lignina dos cavacos oriundos das temperaturas 50, 70, 90 e 110°C nos tempos de 1 e 5 horas. Para os processos de polpação avaliou-se, o rendimento bruto, rendimento depurado, teor de rejeitos, ácidos hexenurônicos e alvura, além da eficiência da adição de um estágio de préextração aquosa. Os resultados obtidos mostram que a matéria-prima apresentou valores típicos para a espécie em questão no que diz respeito à densidade básica, composição química e morfologia das fibras. Através de uma regressão com os resultados de absorção de água e extrativos totais nas diferentes temperaturas foi estabelecido a temperatura 80°C e tempo de 1 hora como a ideal para a préextração aquosa. Para o processo de polpação kraft convencional o nível de deslignificação foi obtido com carga alcalina de 14% (base NaOH); para o processo SuperBatchTM o nível de deslignificação estabelecido foi obtido com uma carga de reagentes químicos de 16% (base NaOH). A impregnação aquosa contribuiu para uma melhor deslignificação somente no processo convencional. / The present study aimed to evaluate and compare the kraft pulping conventional processes and SuperBatchTM for Bambusa vulgaris aiming the production of pulp unbleached (kappa number 58 ± 2). The raw material was characterized with respect to basic density, chemical composition and morphology of fibers, was analyzed an aqueous pre-extraction temperatures of 50, 70 and 90 ° C for 5 hours weighing the chips to every 15 minutes to evaluate the absorption of water. The same procedure was done for 110 ° C were used time of 15 minutes, 1, 2 and 5 hours. After this stage were evaluated the total extractives and lignin content from the chips of the temperatures 50, 70, 90 and 110 ° C for 1 and 5 hours. For the pulping processes were evaluated, the total yield, screened yield, reject content, HexA and brightness, besides the efficiency of the addition of a pre-stage aqueous extraction. The results show that the raw material had values typical for the species in question with regard to density, chemical composition and fibers morphology. Through a regression with the results of water absorption and extractives was set at different temperatures the temperature 80 ° C as optimal for pre-aqueous extraction. For the conventional kraft pulping process the level of delignification was obtained with the alkali charge of 14% (based on NaOH); SuperBatchTM process for the level of delignification has been achieved with a set of chemical reactants load 16% (base NaOH). The aqueous pre-extraction contributed to a better delignification only in the conventional process.

A utilização de fibras vegetais como reforço de matrizes frágeis de cimento é justificada pelo baixo custo, alta disponibilidade, principalmente em países como o Brasil, que possui agricultura desenvolvida, boas condições edafo-climáticas e grandes áreas para cultivo. No entanto, em razão da alta alcalinidade do cimento a matriz reforçada tem a durabilidade comprometida pela degradação das fibras. Uma medida para minimizar esse ataque alcalino é a dissolução da lignina e da hemicelulose das fibras, menos resistentes em condições de pH elevado, através da polpação química, processo que individualiza as fibras celulósicas, que podem ser utilizadas como reforço de compósitos cimentícios em substituição parcial às fibras sintéticas. As polpas aplicadas para este fim são comumente produzidas pelo processo Kraft. Uma alternativa mais limpa a este processo é a polpação organossolve que usa reagentes orgânicos durante o cozimento e proporciona facilidade para recuperação do solvente no final do processo. O bambu possui fibras de elevada resistência mecânica, portanto sua utilização como matéria-prima para produção de polpas celulósicas é justificada por ser um material viável, de fácil aplicação, rápido crescimento e pronta disponibilidade. A proposta deste trabalho foi a produção de polpa de bambu pelo processo organossolve utilizando as variáveis tempo x temperatura com a finalidade de encontrar a condição ótima para o processo, de forma que houvesse melhor rendimento e que as características químicas, físicas e morfológicas da polpa fossem compatíveis às exigidas para utilização como reforço de matrizes cimentícias. A melhor condição foi o cozimento a temperatura de 190ºC durante 2 h. O tempo de 1 h de cozimento foi insuficiente para a solubilização da lignina e o período de 3 h é inviável devido a degradação da cadeia de celulose. Foram produzidos pelo método de sucção a pressão negativa, compósitos com matriz de cimento com substituição parcial de metacaulim e testados os teores de 6, 8, 10 e 12% de polpa de bambu como reforço. O teor de polpa definido como ideal foi 8%, o mesmo encontrado na literatura para polpa Kraft de bambu. Produziram-se placas com duas composições. Uma com substituição parcial de 25% do cimento por metacaulim e a segunda com substituição de 25% do cimento por calcário moído. Os compósitos contendo metacaulim foram submetidos a envelhecimento acelerado por meio de 50, 100 e 200 ciclos de imersão e secagem para avaliação da durabilidade. As propriedades físicas foram melhoradas com os ciclos de envelhecimento, ocasionando diminuição na porosidade aparente pela migração dos produtos da hidratação do cimento para a zona em torno das fibras, e, em consequência, melhorias nas propriedades mecânicas de módulo de ruptura (MOR), limite de proporcionalidade (LOP) e módulo de elasticidade (MOE), tanto para a substituição parcial do cimento por metacaulim como para calcário. Houve diminuição na energia específica (EE) com os ciclos de imersão e secagem, justificada pela maior aderência entre fibra-matriz. Observados os parâmetros de polpação organossolve adotados para o bambu, essa polpa apresenta-se viável para reforço de matrizes inorgânicas a base de cimento Portland. / The use of natural fibers as reinforcement for brittle cement matrices is justified by the its low cost, high availability, especially in countries like Brazil, which has developed agriculture, good soil and climatic conditions and large areas for cultivation. However, due to the high alkalinity of cement the reinforced matrix has it durability compromised by the fiber degradation. One measure to minimize this alkaline attack is the dissolution of lignin and hemicellulose fibers, that are less resistant under conditions of high pH, by chemical pulping, that is a process that individualizes the cellulosic fibers, which can be used as reinforcement of cementitious composites in partial replacement synthetic fibers. The pulps applied for this purpose are commonly produced by the kraft pulping process. A cleaner alternative to this process is the organosolv pulping that use organic reagents during cooking and provides facility for solvent recovery at the end of the process.The bamboo fibers have high mechanical strength, therefore their use as raw materials for production of cellulose pulps is justified because it is a viable material, easily applied, rapid growth and ready availability. The purpose of this study was the production of bamboo pulp by the organosolv process using the variables time vs temperature in order to find the optimum condition for the process, so that there was a better yield and that the chemical, physical and morphological characteristics of the pulp were compatible to those required for use as reinforcement in cementitious matrices. The best condition was the cooking temperature of 190ºC for 2 h. The time of 1 h of cooking was insufficient to solubilize the lignin and the time of 3 h is infeasible due to degradation of the cellulose chain. The composites with matrix of cement and with partial replacement of metakaolin were produced by the method of negative pressure suction and tested the levels of 6, 8, 10 and 12% bamboo pulp as reinforcement. The pulp content was defined as an ideal 8%, as found in the literature for bamboo Kraft pulp. The plates were produced with two compositions. One with partial substitution of cement by 25% of metakaolin and the second with 25% replacement of cement by limestone. The composites containing metakaolin were subjected to accelerated ageing through 50, 100 and 200 wet and dry cycles for durability evaluation. The physical properties were improved with the ageing cycles, decreasing the porosity by migration of the cement hydration products to the zone around the fibers and, consequently, improvements in mechanical properties of modulus of rupture (MOR), limit proportionality (LOP) and modulus of elasticity (MOE) for both the partial replacement of cement by metakaolin as for limestone. The decreased of the specific energy (EE) with the wet and dry cycles was due to the higher adhesion between fiber-matrix. With the observation of the parameters adopted for bamboo organosolv pulping, this pulp has to be feasible for reinforcement of inorganic matrices based in Portland cement.