996 resultados para Industrial concrete floors


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Trabalho de Projeto para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Estruturas

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The eco-efficient, self-compacting concrete (SCC) production, containing low levels of cement in its formulation, shall contribute for the constructions' sustainability due to the decrease in Portland cement use, to the use of industrial residue, for beyond the minimization of the energy needed for its placement and compaction. In this context, the present paper intends to assess the viability of SCC production with low cement levels by determining the fresh and hardened properties of concrete containing high levels of fly ash (FA) and also metakaolin (MK). Hence, 6 different concrete formulations were produced and tested: two reference concretes made with 300 and 500 kg/m3 of cement; the others were produced in order to evaluate the effects of high replacement levels of cement. Cement replacement by FA of 60% and by 50% of FA plus 20% of MK were tested and the addition of hydrated lime in these two types of concrete were also studied. To evaluate the self-compacting ability slump flow test, T500, J-ring, V-funnel and L-box were performed. In the hardened state the compressive strength at 3, 7, 14, 21, 28 and 90 days of age was determined. The results showed that it is possible to produce low cement content SCC by replacing high levels of cement by mineral additions, meeting the rheological requirements for self-compacting, with moderate resistances from 25 to 30 MPa after 28 days.

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Projeto de Investigação integrado de mestrado Internacional em Sustentabilidade do Ambiente Construído

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L’objectiu d’aquest treball és realitzar un projecte on es buscaran diferents tipus de sabates prefabricada de formigó que hi ha en el mercat, per tal de seleccionar la més adequada a través d’una sèrie de càlculs, tant des del punt de vista tècnic, de facilitat de muntatge i de transport, com econòmic, i d’aquesta manera arribar a una solució. Aquest projecte és un subprojecte d’un altre que correspon a la construcció de la totalitat de la nau industrial prefabricada. Per tant, la part important d’aquest projecte és l’estudi de les sabates prefabricades de formigó, el qual, es realitzarà partint d’una informació addicional, que aparentment sembla poc important, però, en realitat, és imprescindible per dur-lo a terme

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Much effort is being expended by various state, federal, and private organizations relative to the protection and preservation of concrete bridge floors. The generally recognized culprit is the chloride ion, from the deicing salt, reaching the reinforcing steel, and along with water and oxygen, causing corrosion. The corrosion process exerts pressure which eventually causes cracks and spalls in the bridge floor. The reinforcing· has been treated and coated, various types of "waterproof" membranes have been placed on the deck surface, decks have been surfaced with dense and modified concretes, decks have been electrically protected, and attempts to internally seal the concrete have been made. As of yet, no one method has been proven and accepted by the various government agencies as being the "best" when considering the initial cost, application effort, length and effectiveness of protection, etc.

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This is a continuation of a project initiated a year ago to determine any differences in test results on recovered asphalt cements caused by the use of industrial grade of solvent as compared with the reagent grade. AASHTO specifies the use of reagent grade of trichlorethylene, but the Laboratory uses industrial grade which costs much less. Last year this objective of the project was aborted when it was found that a larger difference in test results was obtained between the two distillation apparatuses than between the two solvents, Then all efforts were directed toward obtaining uniformity in test results between the apparatuses under the east hood as compared with that under the west hood. Considerable progress was made toward this end. (See report under this same title dated April 1982). The objective this year was to again evaluate the results when using both variables (apparatuses and solvents). Another objective developed later in this investigation; this was to determine any differences in test results on recovered asphalt cements caused by the use of reclaimed trichlorethylene (from the distillation process) as compared with the use of industrial grade of solvent. At the present time the reclaimed trichlorethylene is discarded. If the reclaimed solvent could be used for further recoveries, a considerable savings in solvent costs would result.

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Verkostoitunut kansainvälinen tuotekehitys on tärkeä osa menestystä nykypäivän muuttuvassa yritysmaailmassa. Toimintojen tehostamiseksi myös projektitoiminnot on sopeutettava kansainväliseen toimintaympäristöön. Kilpailukyvyn säilyttämiseksi projektitoimintoja on lisäksi jatkuvasti tehostettava. Yhtenäkeinona nähdään projektioppiminen, jota voidaan edistää monin eri tavoin. Tässätyössä keskitytään projektitiedonhallinnan kehittämisen tuomiin oppimismahdollisuuksiin. Kirjallisuudessa kerrotaan, että projektitiedon jakaminen ja sen hyödyntäminen seuraavissa projekteissa on eräs projektioppimisen edellytyksistä. Tämäon otettu keskeiseksi näkökulmaksi tässä tutkimuksessa. Lisäksi tutkimusalueen rajaamiseksi työ tarkastelee erityisesti projektioppimista kansainvälisten tuotekehitysprojektien välillä. Työn tavoitteena on esitellä keskeisiä projektioppimisen haasteita ja etsiä konkreettinen ratkaisu vastaamaan näihin haasteisiin. Tuotekehitystoiminnot ja kansainvälinen hajautettu projektiorganisaatio kohtaavat lisäksi erityisiä haasteita, kuten tiedon hajautuneisuus, projektihenkilöstön vaihtuvuus, tiedon luottamuksellisuus ja maantieteelliset haasteet (esim. aikavyöhykkeet ja toimipisteen sijainti). Nämä erityishaasteet on otettu huomioon ratkaisua etsittäessä. Haasteisiin päädyttiin vastaamaan tietotekniikkapohjaisella ratkaisulla, joka suunniteltiin erityisesti huomioiden esimerkkiorganisaation tarpeet ja haasteet. Työssä tarkastellaan suunnitellun ratkaisun vaikutusta projektioppimiseen ja kuinka se vastaa havaittuihin haasteisiin. Tuloksissa huomattiin, että projektioppimista tapahtui, vaikka oppimista oli vaikea suoranaisesti huomata tutkimusorganisaation jäsenten keskuudessa. Projektioppimista voidaan kuitenkin sanoa tapahtuvan, jos projektitieto on helposti koko projektiryhmän saatavilla ja se on hyvin järjesteltyä. Muun muassa nämä ehdot täyttyivät. Projektioppiminen nähdään yleisesti haastavana kehitysalueena esimerkkiorganisaatiossa. Suuri osa tietämyksestä on niin sanottua hiljaistatietoa, jota on hankala tai mahdoton saattaa kirjalliseen muotoon. Näin olleen tiedon siirtäminen jää suurelta osin henkilökohtaisen vuorovaikutuksen varaan. Siitä huolimatta projektioppimista on mahdollista kehittää erilaisin toimintamallein ja menetelmin. Kehitys vaatii kuitenkin resursseja, pitkäjänteisyyttä ja aikaa. Monet muutokset voivat vaatia myös organisaatiokulttuurin muutoksen ja vaikuttamista organisaation jäseniin. Motivaatio, positiiviset mielikuvat ja selkeät strategiset tavoitteet luovat vakaan pohjan projektioppimisen kehittämiselle.

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Työssä oli tavoitteena suunnitella globaali sovellusarkkitehtuuri, joka ohjaa teollisen huoltoyrityksen sovellusten kehitystyötä. Sovellusarkkitehtuuri kuvaa tietokoneohjelmien toiminnallisuuteen loppukäyttäjien näkökulmasta ja sen laatiminen on osa strategista tietojärjestelmäsuunnittelua. Arkkitehtuurin tehtävänä on varmistaa, että tietojärjestelmät suunnitellaan kokonaisuutena tukemaan organisaation toimintaa. Arkkitehtuurin tekemistä ohjasi strategisen tietojärjestelmäsuunnittelun periatteet ja mallit. Tekniikat olivat samoja kuin projektikohtaisessa tietojärjestelmäsuunnittelussa. Sovellusarkkitehtuurin tekeminen alkoi tutustumalla yrityksessä vallitsevaan tilanteeseen sekä liiketoiminta- ja tietotekniikkastrategioihin. Tarkastelun kohteena olivat pääasiassa liiketoimintaprosessit ja käytössä olevat sovellukset. Tutustuminen tapahtui lähinnä haastatteluin ja dokumentteihin tutustumalla. Seuraavaksi johdettiin vaatimukset tulevaisuuden sovelluksille haastatteluista ja edellisen vaiheen materiaalin perusteella. Liiketoiminnan kannalta tärkeimmät vaatimukset valittiin täytettäväksi arkkitehtuurilla. Varsinaisen arkitehtuurin tekeminen oli lähinnä sovellusten valitsemisesta ja niiden keskinäisten suhteiden määrittelyä. Arkkitehtuurin perusteella määritettiin kehityshankeet.

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Scientific studies regarding specifically references do not seem to exist. However, the utilization of references is an important practice for many companies involved in industrial marketing. The purpose of the study is to increase the understanding about the utilization of references in international industrial marketing in order to contribute to the development of a theory of reference behavior. Specifically, the modes of reference usage in industry, the factors affecting a supplier's reference behavior, and the question how references are actually utilized, are explored in the study. Due to the explorative nature of the study, a research design was followed where theory and empirical studies alternated. An Exploratory Framework was developed to guide a pilot case study that resulted in Framework 1. Results of the pilot study guided an expanded literature review that was used to develop first a Structural Framework and a Process Framework which were combined in Framework 2. Then, the second empirical phase of the case study was conducted in the same (pilot) case company. In this phase, Decision Systems Analysis (DSA) was used as the analysis method. The DSA procedure consists of three interviewing waves: initial interviews, reinterviews, and validating interviews. Four reference decision processes were identified, described and analyzed in the form of flowchart descriptions. The flowchart descriptions were used to explore new constructs and to develop new propositions to develop Framework 2 further. The quality of the study was ascertained by many actions in both empirical parts of the study. The construct validity of the study was ascertained by using multiple sources of evidence and by asking the key informant to review the pilot case report. The DSA method itself includes procedures assuring validity. Because of the choice to conduct a single case study, external validity was not even pursued. High reliability was pursued through detailed documentation and thorough reporting of evidence. It was concluded that the core of the concept of reference is a customer relationship regardless of the concrete forms a reference might take in its utilization. Depending on various contingencies, references might have various tasks inside the four roles of increasing 1) efficiency of sales and sales management, 2) efficiency of the business, 3) effectiveness of marketing activities, and 4) effectiveness in establishing, maintaining and enhancing customer relationships. Thus, references have not only external but internal tasks as well. A supplier's reference behavior might be affected by many hierarchical conditions. Additionally, the empirical study showed that the supplier can utilize its references as a continuous, all pervasive decision making process through various practices. The process includes both individual and unstructured decision making subprocesses. The proposed concept of reference can be used to guide a reference policy recommendable for companies for which the utilization of references is important. The significance of the study is threefold: proposing the concept of reference, developing a framework of a supplier's reference behavior and its short term process of utilizing references, and conceptual structuring of an unstructured and in industrial marketing important phenomenon to four roles.

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L’objectiu d’aquest treball és realitzar un projecte on es buscaran diferents tipus de sabates prefabricada de formigó que hi ha en el mercat, per tal de seleccionar la més adequada a través d’una sèrie de càlculs, tant des del punt de vista tècnic, de facilitat de muntatge i de transport, com econòmic, i d’aquesta manera arribar a una solució. Aquest projecte és un subprojecte d’un altre que correspon a la construcció de la totalitat de la nau industrial prefabricada. Per tant, la part important d’aquest projecte és l’estudi de les sabates prefabricades de formigó, el qual, es realitzarà partint d’una informació addicional, que aparentment sembla poc important, però, en realitat, és imprescindible per dur-lo a terme

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El uso de materiales compuestos de matriz polimérica (FRP) emerge como alternativa al hormigón convencionalmente armado con acero debido a la mayor resistencia a la corrosión de dichos materiales. El presente estudio investiga el comportamiento en servicio de vigas de hormigón armadas con barras de FRP mediante un análisis teórico y experimental. Se presentan los resultados experimentales de veintiséis vigas de hormigón armadas con barras de material compuesto de fibra de vidrio (GFRP) y una armada con acero, todas ellas ensayadas a flexión de cuatro puntos. Los resultados experimentales son analizados y comparados con algunos de los modelos de predicción más significativos de flechas y fisuración, observándose, en general, una predicción adecuada del comportamiento experimental hasta cargas de servicio. El análisis de sección fisurada (CSA) estima la carga última con precisión, aunque se registra un incremento de la flecha experimental para cargas superiores a las de servicio. Esta diferencia se atribuye a la influencia de las deformaciones por esfuerzo cortante y se calcula experimentalmente. Se presentan los aspectos principales que influyen en los estados límites de servicio: tensiones de los materiales, ancho máximo de fisura y flecha máxima permitida. Se presenta una metodología para el diseño de dichos elementos bajo las condiciones de servicio. El procedimiento presentado permite optimizar las dimensiones de la sección respecto a metodologías más generales.

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El uso de barras de materiales compuestos (FRP) se propone como una alternativa efectiva para las tradicionales estructuras de hormigón armadas con acero que sufren corrosión en ambientes agresivos. La aceptación de estos materiales en el mundo de la construcción está condicionada a la compresión de su comportamiento estructural. Este trabajo estudia el comportamiento adherente entre barras de FRP y hormigón mediante dos programas experimentales. El primero incluye la caracterización de la adherencia entre barras de FRP y hormigón mediante ensayos de pull-out y el segundo estudia el proceso de fisuración de tirantes de hormigón reforzados con barras de GFRP mediante ensayo a tracción directa. El trabajo se concluye con el desarrollo de un modelo numérico para la simulación del comportamiento de elementos de hormigón reforzado bajo cargas de tracción. La flexibilidad del modelo lo convierte en una herramienta flexible para la realización de un estudio paramétrico sobre las variables que influyen en el proceso de fisuración.

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Pós-graduação em Engenharia Civil - FEIS

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This study compares two educational practices: the Rural School method (Escola do Campo) and the SESI teaching method, suggesting that the latter one is inefficient when applied to rural schools, as illustrated with a case study of a rural school that was obliged to adopt this method in 2012. The epistemological basis of a dialogical pedagogy for rural education has been used in order to criticize the practices of a method whose origins in the industrial ideology and in consumerism promotes a true cultural invasion, according to Paulo Freire, hindering the students' dialogues with respect to the ways of life in rural areas and in towns – an interaction that assured school performance in the previous educational system, which has been arbitrarily discontinued by the political power. Different surveys were used in this study for both compared cases, specially dissertations that have evaluated the Rural School project (Projeto Escola do Campo), adopted in Araraquara in 2004, a dissertation about the SESI teaching method that has discussed its new didactic material and, also, an evaluation of the contents of a representative sample of textbooks of History, Geography, Sciences and Mathematics for the 6th grade of elementary school. It is a theoretical text, not an essay, considering that it is based on concrete situations, which were explained using researches on the implicit themes and summarizes the analytical procedures that have allowed to unveil, in the textbooks prepared by SESI, the stimulus and the valorization of consumerism, without any criticism and environment concerns.

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The practice of running has consistently increased worldwide, and with it, related lower limb injuries. The type of running surface has been associated with running injury etiology, in addition other factors, such as the relationship between the amount and intensity of training. There is still controversy in the literature regarding the biomechanical effects of different types of running surfaces on foot-floor interaction. The aim of this study was to investigate the influence of running on asphalt, concrete, natural grass, and rubber on in-shoe pressure patterns in adult recreational runners. Forty-seven adult recreational runners ran twice for 40 m on all four different surfaces at 12 +/- 5% km . h(-1). Peak pressure, pressure-time integral, and contact time were recorded by Pedar X insoles. Asphalt and concrete were similar for all plantar variables and pressure zones. Running on grass produced peak pressures 9.3% to 16.6% lower (P < 0.001) than the other surfaces in the rearfoot and 4.7% to 12.3% (P < 0.05) lower in the forefoot. The contact time on rubber was greater than on concrete for the rearfoot and midfoot. The behaviour of rubber was similar to that obtained for the rigid surfaces - concrete and asphalt - possibly because of its time of usage (five years). Running on natural grass attenuates in-shoe plantar pressures in recreational runners. If a runner controls the amount and intensity of practice, running on grass may reduce the total stress on the musculoskeletal system compared with the total musculoskeletal stress when running on more rigid surfaces, such as asphalt and concrete.