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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Contribui??o ao estudo dos concretos compostos com agregados gra?dos de constru??o e demoli??o e cinza volante, em diferentes teores de substitui??o

Silva, S?rgio Roberto da 30 March 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:08:23Z No. of bitstreams: 1 DIS_SERGIO_ROBERTO_DA_SILVA_COMPLETO.pdf: 2644731 bytes, checksum: 207623c4aecda0de23cefed577f3f2d6 (MD5) / Made available in DSpace on 2017-06-30T18:08:23Z (GMT). No. of bitstreams: 1 DIS_SERGIO_ROBERTO_DA_SILVA_COMPLETO.pdf: 2644731 bytes, checksum: 207623c4aecda0de23cefed577f3f2d6 (MD5) Previous issue date: 2017-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Nowadays, searching for alternatives materials for the construction industry has become imperative. Construction and demolition waste (CDW) and by-products from the thermoelectric industries, such as fly ash, are the subject of studies in several segments of the construction industry. Their use can be one of many significant efforts to achieve a more sustainable construction. This paper studies the influence of the interactions and incorporations of CDW and fly ash on the concrete properties. X-ray diffraction (XRD), X-ray Fluorescence Spectrometry (XRF) and particle size distribution analysis were used to characterize the investigated materials. The mechanical properties (compressive strength and splitting strength) and durability (water absorption and carbonation depth) of concrete with different CDW contents (25%, 50%, 75%, and 100%) were investigated as a coarse aggregate (10%, 15%, 25% and 30%) replacing Portland cement in different water/binder ratios (0.40, 0.45, 0.50, 0, 55 and 0.65). Based on the results, it was observed that the addition of fly ash replacing the Portland cement in concretes with CDW causes a reduction in mechanical properties and durability of concretes in the early ages. However, as the fly ash content increases in concretes with CDW there is an increase in the compressive strength ratio (fc91/fc28), and as the time of exposure to CO2 advances the carbonation coefficient tends to decrease. / A busca de novos materiais para o emprego na ind?stria da constru??o civil se faz necess?rio nos dias atuais. O res?duo da constru??o e demoli??o (RCD) e os subprodutos das ind?strias termoel?tricas como a cinza volante s?o objetos de estudos em diversos segmentos da ind?stria da constru??o civil, e a adi??o destes materiais pode ser um dos esfor?os significativos para se alcan?ar uma constru??o mais sustent?vel. Neste trabalho foram estudadas a influ?ncia das intera??es e incorpora??es de RCD e cinza volante nas propriedades dos concretos. Para a caracteriza??o dos materiais investigados foram utilizadas as t?cnicas de Difra??o de raios X (DRX), an?lise qu?mica por Espectrometria de Fluoresc?ncia de raios X (FRX) e an?lise de distribui??o granulom?trica ? laser. Foram investigadas as propriedades mec?nicas (compress?o axial e tra??o por compress?o diametral) e de durabilidade (absor??o d??gua e resist?ncia ? carbonata??o) dos concretos com diferentes teores de RCD (25%, 50%, 75% e 100%) como agregado gra?do reciclado em substitui??o ao gra?do natural e adi??o de cinza volante (10%, 15%, 25% e 30%) em substitui??o ao cimento Portland em diferentes rela??es ?gua/aglomerante (0,40, 0,45, 0,50, 0,55 e 0,65). Com base nos resultados observou-se que a adi??o de cinza volante em substitui??o ao cimento Portland em concretos com RCD causa uma redu??o nas propriedades mec?nicas e de durabilidade nos concretos nas primeiras idades. Entretanto, ? medida que o teor de cinza volante aumenta nos concretos com RCD h? um aumento na taxa de resist?ncia ? compress?o axial (fc91/fc28), e ? medida que o tempo de exposi??o ao CO2 vai se avan?ando o coeficiente de carbonata??o tende a diminuir.
2

Concreto com agregado gra?do reciclado de concreto: dosagem e produ??o

Santos, Ana Am?lia Mota dos 04 August 2016 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-02-02T00:09:36Z No. of bitstreams: 1 CONCRETO COM AGREGADO GRAU?DO RECICLADO DE CONCRETO_DOSAGEM E PRODUC?A?O.pdf: 3147518 bytes, checksum: 5fc02389f0e0978e3636005417e03f9e (MD5) / Made available in DSpace on 2017-02-02T00:09:36Z (GMT). No. of bitstreams: 1 CONCRETO COM AGREGADO GRAU?DO RECICLADO DE CONCRETO_DOSAGEM E PRODUC?A?O.pdf: 3147518 bytes, checksum: 5fc02389f0e0978e3636005417e03f9e (MD5) Previous issue date: 2016-08-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / A proper mix design and production must be done in order to increase the use of recycled concrete. The type of recycled aggregate (RA) used, the best replacement content, the best sequence and mixing time and the best way to evaluate the workability are some of the features that must be considered. Thus, this work was done to evaluate the mix design and production of concrete with concrete recycled coarse aggregate (RCA), using as a measure of workability the flow test in Graff?s table. Two levels of recycled coarse aggregate (20 and 40%), two levels of flow, for plastic and fluid mixtures, (350 and 400mm), and two mix design methods (IPT/EPUSP and ABCP) were evaluated on the concrete compressive strength, at 7 and 28 days of age. The results pointed out that the IPT/EPUSP mix design method was more suitable for recycled concrete. The flow test in Graff?s table, as a measure of workability, and the two stage mixture approach presented to be more suitable for the mix design and production of recycled concrete. Also, in this study, the concrete RCA content evaluated did not influence the compressive strength of concrete produced. So, it is completely feasible to use up to 40% replacement of NCA by concrete RCA. / Para ampliar o uso de concretos reciclados deve-se estabelecer a sua dosagem e produ??o considerando aspectos relacionados com o tipo de agregado reciclado (AR) utilizado, o melhor teor de AR, a melhor sequ?ncia e tempo de mistura e a melhor forma de avaliar a trabalhabilidade desses concretos. Assim, este trabalho foi desenvolvido com o objetivo de avaliar a dosagem e produ??o de concretos com ARs de concreto, usando como medida de trabalhabilidade o ensaio de espalhamento na mesa de Graff. Os teores de aplica??o do agregado gra?do reciclado(AGR) foram 20 e 40%. Foram avaliados dois n?veis de espalhamento (350 e 400mm) e dois m?todos de dosagem (IPT/EPUSP e ABCP). Os concretos foram avaliados ainda quanto a resist?ncia ? compress?o axial, aos 7 e 28 dias, e os resultados obtidos foram tratados estatisticamente atrav?s da an?lise de vari?ncia(ANOVA). Os resultados mostraram que o m?todo de dosagem do IPT/EPUSP apresentou-se mais adequado para a dosagem de concretos reciclados. O ensaio de espalhamento na mesa de Graff, como medida da trabalhabilidade, e o m?todo de mistura em duas etapas apresentaram-se adequados para a dosagem e produ??o de concretos reciclados. Nesse estudo, o teor de AGR avaliado n?o influenciou a resist?ncia ? compress?o dos concretos produzidos, sendo plenamente vi?vel o uso de at? 40% do agregado gra?do reciclado de concreto.
3

An?lise da Permeabilidade e da Colmata??o em Concretos Perme?veis produzidos com Agregado Reciclado de Concreto / Permeability and Clogging in Pervious Concrete with Construction residues aggregate

Oliveira, Lilian Corpas Bucene 14 December 2017 (has links)
Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2018-02-16T17:20:40Z No. of bitstreams: 1 LILIAN CORPAS BUCENE OLIVEIRA.pdf: 2456363 bytes, checksum: dfcf0b460775e677213c888d5bb3611d (MD5) / Made available in DSpace on 2018-02-16T17:20:40Z (GMT). No. of bitstreams: 1 LILIAN CORPAS BUCENE OLIVEIRA.pdf: 2456363 bytes, checksum: dfcf0b460775e677213c888d5bb3611d (MD5) Previous issue date: 2017-12-14 / Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo - FAPESP / The growth of urban centers has created new challenges for construction activities. It?s not only the environmental point of view, but also from logistical and economic reasons, two aspects that stand out, which are the management of rainwater and a destination of solid construction and demolition residues aggregate (RCD) . One of the alternatives to relieve the drainage system is the pervious concrete pavement (PCP), which allow infiltration of water into the base or soil, reducing floodings, water accumulations on roads and improving aquifers supply. The PCP employs in its composition, little or no fine aggregates, what providing a higher a volume of voids to the element, and consequently permeability. The addition of RCD in the pervious concrete?s composition is justified both by the increasing difficulty of disposal of these materials and by the reduction of the extraction of natural aggregates, favoring a reduction of the environmental impacts generated by the civil construction. Therefore, the production of pavement using pervious concrete made with recycled concrete aggregate (ARC) is one of the alternatives that has been researched to reduce the environmental impact of construction, protecting water resources and being able to avoid flood areas of flood with a lower consumption of natural goods. The effectiveness of water infiltration capability can be partially compromised due to the occurrence of clogging, which is influenced by the type and size of the infiltrated sediment into to the water and the precipitation intensity. This research studied two different types of PCP, produced with and without ARC, evaluating their behavior regarding mechanical, physical and hydraulic properties. A comparison was also made between different types of sediments to simulate the permeation of the pervious concrete. For this, laboratory studies were carried out and also equipment was developed to simulate a real situation of application of this type of concrete. It was observed the influence on the characteristics of PCP, with the use of ARC, as well as the permeability index after filling with various types of materials. The PCP using recycled aggregates obtained a satisfactory result, it was also verified that the test method to obtain the permeability index or the infiltration rate influenced in the analysis. It may also be noted that the adaptation of ?in situ? laboratory tests performed in the laboratory has not been shown to be adequate to the actual situation due to the influence of the floor base. / O crescimento dos centros urbanos tem produzido novos desafios ?s atividades da constru??o civil. N?o apenas do ponto de vista ambiental, mas tamb?m por quest?es log?sticas e econ?micas, dois aspectos v?m se destacando no ?mbito do setor nas grandes metr?poles, que s?o o manejo de ?guas de chuvas e a destina??o de res?duos s?lidos de constru??o e demoli??o (RCD). Uma das ferramentas que pode ser utilizada para aliviar o sistema de drenagem ? o emprego de pavimentos de concreto perme?vel (PCP), que permitem a infiltra??o de ?gua na base ou no solo, diminuindo os picos de cheia, ac?mulos de ?gua nas vias p?blicas, melhorando o abastecimento dos aqu?feros. O PCP ? uma mistura que emprega na sua composi??o pouco ou nenhum agregado mi?do, proporcionando maior ?ndice de vazios ao concreto, e consequentemente um elevado coeficiente de permeabilidade. A adi??o do RCD na composi??o do concreto perme?vel justifica-se tanto pela crescente dificuldade de descarte desses materiais quanto pela redu??o da extra??o de agregados naturais, propiciando uma redu??o dos impactos ambientais gerados pela constru??o civil. Portanto, a produ??o de pisos, usando o PCP elaborado com o agregado reciclado de concreto (ARC) proveniente do RCD, ? uma das alternativas que v?m sendo pesquisada para reduzir o impacto ambiental da constru??o, protegendo os recursos h?dricos e evitando ?reas de inunda??o com um menor consumo de bens naturais. A efic?cia da taxa de infiltra??o da ?gua de chuva no concreto perme?vel pode ser parcialmente comprometida devido ? ocorr?ncia da colmata??o, que ? influenciada pelo tipo e tamanho do sedimento infiltrado junto ? ?gua e a intensidade da precipita??o. Esta pesquisa estudou dois diferentes tipos de PCP, produzidos com e sem ARC, avaliando seu comportamento quanto ?s propriedades mec?nicas, f?sicas e hidr?ulicas. Tamb?m foi realizada uma compara??o entre diferentes tipos de sedimentos para simula??o da colmata??o do concreto perme?vel, para tal, foram realizados estudos em equipamentos desenvolvidos para simula??o do processo de colmata??o em um canteiro real. Observou-se a influ?ncia nas caracter?sticas do PCP, com o emprego do ARC, bem como a taxa de infiltra??o ap?s colmata??o com v?rios tipos de materiais. O emprego do ARC propiciou resultado satisfat?rio nas caracter?sticas do concreto perme?vel e verificou-se que os m?todos de ensaio para obten??o do coeficiente de permeabilidade ou da taxa de infiltra??o influenciam na an?lise do concreto perme?vel. Tamb?m pode-se notar que a adapta??o de ensaios para an?lise ?in loco? reproduzidos em laborat?rio n?o se mostrou adequada ? situa??o real devido a influ?ncia da base dos pavimentos.

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