El objetivo principal de la presente investigación es idear un sistema que logre disminuir el costo y el tiempo de elaboración de muros no portantes de albañilería confinada. Para lograrlo se ha diseñado un sistema de bloques de arcilla apilables en seco y autoencajables que cumple con todas las normas imputables. Para determinar el rendimiento del sistema diseñado se fabricaron las piezas y se construyó un muro con medidas típicas. Los resultados para dicho caso de estudio se resumen en un ahorro de 17% en el costo directo (considerando todo el muro en su conjunto) y 76% en el tiempo empleado (solo en el asentado de bloques). / The principal objective of this research is to design a system that manage to reduce the cost and time in the construction of non-structural masonry walls. To achieve this, it has been designed a Mortarless Dry-Stacked Interlocking Masonry Clay Bricks which verifies all the imputable codes. To determine the performance of the system, the bricks were made and a wall with typical measurements was built. The results for this study are 17% of reduction in the direct cost (considering the whole wall) and 76 % less time used (alone in the brick seating). / Tesis

Actualmente, el sector construcción es uno de los sectores más contaminantes a nivel mundial, es considerado uno de los máximos aportantes de emisiones de carbono. En esta industria se utilizan materiales como el cemento y acero, cuyos elementos son considerados como materiales con alta energía incorporada. La fabricación de estos materiales tiene un impacto considerable de CO2; el cemento por sí solo, representa el 5% de emisiones de CO2 a nivel mundial. También, la industria concretera es responsable de la extracción indiscriminada de recursos no renovables como el agua y agregados, arena y piedra, provenientes de las canteras, graveras, pedregales, etc. La presente tesis tiene como propósito los análisis comparativos de las propiedades técnicas de mezclas de concreto elaboradas con agregados reciclados y/o sub productos de las industrias como el Clinker de aceite de palma (POC) y caucho; con el fin de disminuir la extracción indiscriminada de agregados de las canteras que son utilizados por la industria concretera. Asimismo, reducir la cantidad de CO2 que es producido por la extracción de estos agregados ya que son altamente contaminantes para el medio ambiente. El trabajo de nuestra investigación se basa en realizar 156 probetas de ensayo con agregados reciclados en la mezcla de concreto dando diferentes beneficios estructurales como el incremento de la flexión, compresión y tracción. Se presenta como un proyecto factible que propone una alternativa eco amigable para contrarrestar el impacto ambiental negativo causado por la industria concretera mediante un estudio comparativo de tres mezclas de concreto empleando materiales reciclados como el POC y caucho en reemplazo parcial de la arena. / Currently, the construction sector is one of the most polluting sectors worldwide, it is considered one of the maximum contributors of carbon emissions. In this industry, materials such as cement and steel are used, whose elements are considered as materials with high energy incorporated. The manufacture of these materials has a considerable CO2 impact; Cement alone represents 5% of CO2 emissions worldwide. Also, the concrete industry is responsible for the indiscriminate extraction of non-renewable resources such as water and aggregates, sand and stone, coming from quarries, gravel, rock, etc. The purpose of this thesis is the comparative analysis of the technical properties of concrete mixtures made from recycled aggregates and / or by-products from industries such as Palm Oil Clinker (POC) and rubber; in order to reduce the indiscriminate extraction of aggregates from quarries that are used by the concrete industry. Also, reduce the amount of CO2 that is produced by the extraction of these aggregates as they are highly polluting for the environment. The work of our research is based on performing 156 test specimens with recycled aggregates in the concrete mixture giving different structural benefits such as increased flexion, compression and traction. It is presented as a feasible project that proposes an eco-friendly alternative to counteract the negative environmental impact caused by the concrete industry through a comparative study of three concrete mixtures using recycled materials such as POC and rubber in partial sand replacement. / Tesis

Yes / Quantification of stocks and flows of construction materials is a key first stage in assessing the potential for creating higher value at end-of-life decisions compared to destructive demolition. Steel and concrete are amongst the most widely used construction materials primarily in structural components. Such components are highly variable in design, type, and dimensions. In the absence of urban-scale digitised models of structural components or building plans, accurate assessment relies on either onsite inspection or modelling by material intensity (MI) co-efficient which can vary by up to a factor of 100. In this study, we extend previous stock modelling approaches through the development of a method that relies on building archetypes and produces MI coefficients of steel and concrete that are representative of frame types, temporally explicit and disaggregated at product level. This is compared to the common existent method of calculating MI to demonstrate the capabilities of the proposed method. Coupled with a spatiotemporal model of urban buildings, the developed MI of both methods are applied to a case study in the UK. The total in-use stock of steel and concrete within multi-storey buildings is estimated at 81,000 tonnes and 655,000 m3 respectively. The stocks of steel and concrete are disaggregated based on their functions as products, for instance steel beams are distinguished from reinforcement steel. Subsequently, the embodied carbon of the in-use stock is calculated as 350 kt CO2eq. The results show the proposed method enables a more granular assessment of the embodied carbon of the structural material quantities. / This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) research grant ‘REBUILD - REgenerative BUILDings and products for a circular economy’ [Grant reference: EP/ P008917/1]

Prior to the implementation of the European Union Urban Waste Water Treatment Directive (91/271/EEC) in 31 Dec 1998, around a quarter of the sewage sludge produced in the UK was either discharged to surface waters via pipes or disposed from ships at sea. Discontinuing this route together with the quality requirements of the European Waste Water Directive, led to the generation of significant quantities of sewage sludge. It has therefore become required to treat this waste effectively before it can be sent back to the environment. Consequently, this added greater challenges for the environmental agencies, as well as local authorities. The treatment process comprises costly and energy consuming applications including physical, chemical, biological and thermal. In addition to the sewage sludge, the power generation industry produces massive quantities of fly ash from burning coal. In the UK, there is about 5,300,000 tonnes of fly ash that are generated annually, which require to be processed and classified in order to meet the standard requirements before it can be used in the construction applications. The classifying process also involves a series of costly and energy consuming mechanical and physical applications. This research programme has introduced an innovative alternative to the traditional re-use and disposal routes of Raw Sewage Sludge (RSS) and unprocessed fly ash. It has suggested the utilisation of RSS and unprocessed fly ash as raw ingredients for the production of sustainable construction materials. This research programme has therefore examined the performance of cement-based materials containing Raw Sewage Sludge (RSS) as a water replacement and unprocessed fly ash as cement replacement. Mortar and concrete mixes incorporating these materials were tested for their flowability/workability, density, Total Water Absorption (TWA), Ultrasonic Pulse Velocity (UPV), compressive strength, flexural strength, drying shrinkage, sulphate attack and leaching properties. Three series of cement-based materials were studied including mortar mixes with RSS and unprocessed fly ash (Series 1), mortar mixes with RSS and large proportions of unprocessed fly ash (Series 2), and concrete mixes with RSS and unprocessed fly ash (Series 3). The outcomes of the investigation were encouraging in that cement-based materials containing RSS and unprocessed fly ash that were produced demonstrated relatively good engineering, durability and environmental properties in comparison to the control mixes. The inclusion of unprocessed fly ash significantly reduced flowability/workability; however it improved long-term compressive strength for both mixes with RSS and water. The best compressive strength results were recorded when cement was replaced with 10-20% unprocessed fly ash by weight of total binder. The results also showed that sulphate attack resistance improved when fly ash was included. Moreover, safe concentration levels of heavy metals and free ions were detected when leaching test was performed. However, it must be kept in mind that more environmental tests must be performed before any large scale use is undertaken.

MOJO

<p>With the advent of Self-Compacting Concrete (SCC) that flows freely, under the soleinfluence of gravity, the wish for hassle-free and predictable castings even in complexcases, spurged the simulation of concrete flow as a means to model and predictconcrete workability. To achieve complete and reliable form filling with smoothsurfaces of the concrete, the reinforced formwork geometry must be compatible withthe rheology of the fresh SCC. Predicting flow behavior in the formwork and linkingthe required rheological parameters to flow tests performed on the site will ensurean optimization of the casting process.In this thesis, numerical simulation of concrete flow is investigated, using both discreteas well as continuous approaches.The discrete particle model here serves as a means to simulate details and phenomenaconcerning aggregates modeled as individual objects. The here presented cases aresimulated with spherical particles. However, it is possible to make use of nonsphericalparticles as well. Aggregate surface roughness, size and aspect ratio maybe modeles by particle friction, size and clumping several spheres into forming thedesired particle shape.The continuous approach has been used to simulate large volumes of concrete. Theconcrete is modeled as a homogeneous material, particular effects of aggregates,such as blocking or segregation are not accounted for. Good correspondence wasachieved with a Bingham material model used to simulate concrete laboratory tests(e.g. slump flow, L-box) and form filling. Flow of concrete in a particularly congestedsection of a double-tee slab as well as two lifts of a multi-layered full scale wall castingwere simulated sucessfully.A large scale quantitative analysis is performed rather smoothly with the continuousapproach. Smaller scale details and phenomena are better captured qualitativelywith the discrete particle approach. As computer speed and capacity constantlyevolves, simulation detail and sample volume will be allowed to increase.A future merging of the homogeneous fluid model with the particle approach to formparticles in the fluid will feature the flow of concrete as the physical suspension thatit represents. One single ellipsoidal particle falling in a Newtonian fluid was studiedas a first step.</p> / <p>Med uppkomsten av självkompakterande betong (SKB) och dess möjligheter att flyta ut under inverkan av endast gravitation uppstod ett behov av att kunna förutsäga och kontrollera även mer komplicerade gjutningar. Numerisk simulering av SKBs flöde kan kommma att utgöra ett kraftfullt verktyg för att optimera gjutprocessen, ge möjlighet att förutsäga nödbvändig arbetbarhet och säkerställa kompatibilitet mellan den armerade formen och betongens reologi. I föreliggande avhandling undersöks betongens flöde med både diskreta och kontinuumbaserade simuleringsmetoder. Den diskreta partikelmodellen används för att simulera detaljer och fenomen hos t.ex. ballast i betong. I de här presenterade simuleringarna används sfäriska partiklar, men det är även möjligt att skapa ballastkorn av olika form. Ballastens ytråhet och storlek kan modelleras med parametrar för friktion och storlek medan sammanfogning av ett flertal partiklar kan ge ekvivalent form. Den kontinuumbaserade ansatsen används för att simulera större flödesmängder. Betongen modelleras som ett homogent material, eventuella effekter av ballastens inverkan, till exempel blockering eller separation, ingår ej. God överensstämmelse har uppnåtts med Binghams materialmodell som applicerats på några av SKBs provningsmetoder (bl a flytsättmått och L-låda) liksom även för större gjutningar. Formfyllnad av en hårt armerad sektion av ett STT-element, liksom två pumpade betongleveranser till en hög vägg, har framgångsrikt simulerats. En kvantitativ övergripande analys av betongflödet i formen kan göras med den kontinuumbaserade ansatsen för att upptäcka zoner med eventuella svårigheter. En högupplöst detaljstudie kompletterar sedan analysen på valda delar av och kring dessa zoner för att fånga partikelfenomen kvalitativt med hjälv av den diskreta modellen. Då datorkapaciteten ökar kommer även större volymer med högre detaljrikedom att kunna simuleras. En framtida modell simulerar med stor sannolikhet partiklar i flöde, vilket till fullo kan fånga betongens egenskaper som suspension. Som ett första steg på vägen har en fallande ellipsoid i en newtonsk vätska simulerats.</p>

The study relates to road management in Nigeria, on one (land locked) state out of the 36 that comprise the country. The state (Sokoto) has a population of over four million people, and the acute shortage of road connections to the majority of its rural inhabitants necessitated the research. The practice of road management in Sokoto is broadly representative of other Nigerian States. Sokoto like all the northern states, is distant from the coast, and its main asset is an abundant supply of cheap labour. Roads provide the principal mode of access, and are a key factor to trade, industry and social development. An intensive literature review was carried out to determine the existing state of knowledge on the problems encountered by practitioners in the field. The review (desk study) occupied the first stage of the research. It rapidly became clear that the topic is seriously under-researched, both internationally and specifically in the study area. The review has also drawn upon a variety of published and unpublished sources, drawing upon the limited amount of quantified and rigorous data that is available, but also assessing the more substantial quantity of partially quantified or impressionistic information to be found in project reports and case studies. For research to be successful, observable indicators must be found for at least some of the abstract concepts used in the theory. In this regard, six months field work (data collection) was carried out in Nigeria as the study's second stage. This translates the research hypothesis into an operational hypothesis. The third stage of the research covers the analysis and validation of data. This includes an interpretation, which serves as a bridge between the theoretical and practical data. The thesis describes how the empirical data has been used in analysis, to spell out parameters that affect rural road management in Nigeria as in many Sub-Saharan Africa. The research revealed the inappropriate use of technology to be the major factor hindering performance. The study suggests some workable operating methods as possible alternatives that can simplify the difficulties of road maintenance under different operating conditions.

With the end of Western Roman rule and the emergence of new polities in the medieval world, it has been assumed that the technology of mortar reverted to a weak and friable building material. However, this period brought about the implementation of large-scale construction projects that still remain as a testament to their high quality construction techniques and materials. In order to meet the needs of its growing populace, the infrastructure of the new capital city of Constantinople was bolstered by these projects, many rivaling the scale and intricacy of Imperial Rome. A prime example of this is the extensive channel networks of the fourth and fifth centuries, built in the hinterland of Constantinople to supply fresh water from springs hundreds of kilometres away. In addition, the sixth century Long Wall of Thrace was built from the Black Sea to the Sea of Marmara as a first line of defense against increased aggression. This project examines the tradition of monumental construction in the Late Antique and early Byzantine world through laboratory analysis of mortars and valuations of the structural makeup of the Water Supply of Constantinople and Anastasian Wall. By investigating the material technology, scale, and labour requirements of these systems, a better understanding can be gained of two of the largest building project of the early medieval period.

Os métodos construtivos de revestimento externo produzidos com argamassa vêm evoluindo ao longo do tempo, apresentando como maior mudança a substituição da aplicação manual pela projeção mecânica. Atualmente destaca-se no mercado o sistema de execução de revestimento externo com argamassa industrializada e projeção mecânica contínua com bombas helicoidais. Por se tratar de uma tecnologia ainda não muito utilizada pelas construtoras brasileiras, faltam dados confiáveis acerca de seu potencial de ganho de produtividade, redução de perdas, diminuição de contingente de mão de obra, exigências de infraestrutura para aplicação e custos envolvidos. Sem parâmetros confiáveis, adotar a tecnologia significa assumir um nível de risco elevado e isto dificulta a tomada de decisão por parte das construtoras e, por consequência, dificulta-se a evolução tecnológica. Buscando contribuir para o necessário avanço nas tecnologias de produção de revestimentos de edifícios, o objetivo desta pesquisa é estabelecer parâmetros em relação à tecnologia de produção de revestimentos de fachada que empregam argamassa com projeção contínua. Para tanto, buscou-se informações em referências como teses, dissertações, textos técnicos, normas nacionais, dentre outras, bem como, acompanhou-se e avaliou-se os resultados da implantação de um método construtivo de revestimento de argamassa com projeção mecânica contínua em uma construtora de São Paulo. Foram realizados um protótipo e um piloto que contribuíram para o desenvolvimento da tecnologia por meio de apresentação de soluções para os problemas encontrados, do levantamento de melhores práticas e de dados para o cálculo de índices de produtividade e perda. Buscou-se, portanto, a consolidação da tecnologia de projeção contínua na construtora anteriormente mencionada e no mercado em geral. / The external rendering constructive methods produced with mortar have evolved over time and the greater change in it was the replacement of manual application by mechanical projection. The currently most prominent system in the market is the outer rendering execution system with industrialized mortar and continuous mechanical projection with helical pumps. Since this technology is not widely used by Brazilian construction companies, there is a lack of reliable data regarding its productivity gain potential, loss reduction, reduction of hand quota of work, infrastructure required for application and costs involved. Without reliable parameters, the decision to implement this technology is highly risky which does not encourage constructions companies to decide to apply it and, therefore, makes its technological evolution harder to be achieved. Aiming to contribute to the necessary advancement in technology for the production of rendering, this research has the objective to establish parameters to the rendering technology that uses industrialized mortar with continuous projection. With this purpose, it was used as source and reference the specialized literature such as thesis, dissertations and scientific papers, as well as both national norms. In addition, the research included the monitoring and assessment of the results from the implementation of a rendering execution method with continuous mechanical projection in a construction company in Sao Paulo. A prototype and a pilot scale were built and they contributed to the development of this technology by presenting solutions for problems identified and through the mapping of best practices and gathering data that allowed the calculation of productivity and loss rates. The goal was, thus, to consolidate the continuous projection technology in the above-mentioned construction company as well as in the market in a broader way.

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.