Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-09-02T12:59:37Z No. of bitstreams: 1 Dissertação - Melquizedec A Rodrigues.pdf: 5096404 bytes, checksum: 822e44f66d8679d306ea87080653ce00 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-09-16T15:19:40Z (GMT) No. of bitstreams: 1 Dissertação - Melquizedec A Rodrigues.pdf: 5096404 bytes, checksum: 822e44f66d8679d306ea87080653ce00 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-09-16T15:26:22Z (GMT) No. of bitstreams: 1 Dissertação - Melquizedec A Rodrigues.pdf: 5096404 bytes, checksum: 822e44f66d8679d306ea87080653ce00 (MD5) / Made available in DSpace on 2015-09-16T15:26:23Z (GMT). No. of bitstreams: 1 Dissertação - Melquizedec A Rodrigues.pdf: 5096404 bytes, checksum: 822e44f66d8679d306ea87080653ce00 (MD5) Previous issue date: 2015-03-09 / Não Informada / The aim of this study is to determine the possible replacement percentage of cement per waste marbles and granites (WMG) of marble shops of Manaus in the production of self-compacting concrete (SCC). The methodology adopted was to hold various laboratory tests: characterization of each constituent material of the CAA; the rheological properties of SCC; and mechanical, physical and chemical properties in the hardened state of SCC. Two superplasticizers have been applied, one on the base and other salts of sulphonated polymer based whose optimum content was determined by testing the slurry Marsh cone. The coarse aggregates and kids were characterized by assays granulometry, specific weight; unit mass in loose state; and unitary mass compressed and dry. The WMG were subjected to density testing and analysis of Fluorescence X Ray. For fresh SCC in the following tests were performed: scattering, scattering T500, V funnel and L box; and Testing of Compressive Strength and flexion, absorption, voids index and the SCC Density in the hardened state, as well as tests on mortar bars to check possible Alkali Aggregate Reaction (AAR). The results were effective for most traits SCC, up to 30% of the cement replacement by WMG when the additive polymer base was used, and up to 20% replacement when the superplasticizer was sulfonated. Fresh in this SCC met the requirements of ISO 15823, behaving like proper concrete for use in most current applications. In the hardened state near showed compressive strength of 35 MPa, may also be used in the production of concrete floors. The resistance to bending achieved in around 7.0 MPa and satisfy the Brazilian standard 15805. For absorption values were comprised between 4.0% and 5.0%, lower than the values found in the literature, for voids and density values were close to other research, 10%. In AAR tests achieved the expansion was less than 0.10%, and the waste classified as harmless by Brazilian standard 15577-4. With the above it can be said that the residues from marble shops may have an alternative destination in civil construction. / O objetivo principal deste trabalho é determinar o percentual de substituição possível de cimento por resíduos de mármores e de granitos (RMG) das marmorarias de Manaus na produção de concreto autoadensável (CAA). A metodologia adotada foi a realização de vários ensaios laboratoriais: de caracterização de cada material constituinte do CAA; das propriedades reológicas do CAA; e das propriedades mecânicas, físicas e químicas do CAA no estado endurecido. Foram aplicados dois superplastificantes, um à base de sais sulfonados e outro à base de polímeros, cujo teor ótimo foi determinado por meio de ensaios de pasta no cone de Marsh. Os agregados graúdos e miúdos foram caracterizados por meio de ensaios de granulometria, massa específica; massa unitária em estado solto; e massa unitária em estado compactado e seco. Os RMG foram submetidos a ensaio de massa específica e análise de Fluorescência de Raios X. Para o CAA no estado fresco foram realizados os seguintes ensaios: Espalhamento, Espalhamento T500, Funil V e Caixa L; e Ensaios de Resistência à Compressão e à Flexão, Absorção, Índice de Vazios e Massa Específica do CAA no estado endurecido, bem como ensaios em barras de argamassas para verificar possível Reação Álcali Agregado (RAA). Os resultados mostraram-se eficazes para a maioria dos traços de CAA, com até 30% de substituição do cimento por RMG quando o aditivo a base de polímeros foi utilizado e de até 20% de substituição quando o superplastificante foi o sulfonado. No estado fresco esse CAA atendeu aos requisitos da NBR 15823, se comportando como concreto adequado para utilização na maioria das aplicações correntes. No estado endurecido apresentaram resistência à compressão próximas de 35 MPa, podendo também ser utilizado na produção de pavimentos de concreto. As resistências à flexão alcançadas, em torno de 7,0 MPa, e satisfazem a NBR 15805. Para absorção os valores ficaram compreendidos entre 4,0% e 5,0%, menores que os valores encontrados na literatura, para o índice de vazios e massa específica os valores ficaram próximos de outras pesquisas, 10%. Nos ensaios de RAA as expansões alcançadas foram menores que 0,10%, sendo os resíduos classificados como inócuo pela NBR 15577-4. Com o exposto pode-se afirmar que os resíduos de marmorarias podem ter uma destinação alternativa na construção civil.

Les bétons autoplaçants (BAP), développés depuis plusieurs années sont encore à l'heure actuelle qualifiés de « nouveaux bétons » car leur utilisation reste modeste bien qu'ils possèdent un fort potentiel de développement. Ce frein peut être expliqué par leur coût plus élevé, leur sensibilité à la ségrégation et à la fissuration due à leur fort retrait ainsi que par le manque de connaissances sur leur durabilité. Les BAP se distinguent des bétons ordinaires principalement par un dosage en éléments fins plus important. Ainsi, l'utilisation de fines additions minérales plus économiques et/ou plus écologiques dans ces bétons parait judicieuse sous certaines conditions. La présente thèse s'inscrit dans ce contexte et a pour objectifs de contribuer au développement de BAP plus écologiques et à l'étude de leur durabilité. Notre choix s'est porté sur deux ciments industriels à forte teneur en additions, le ciment CEM Ill à base de laitier de haut fourneau et le ciment CEM V à base de cendres volantes et de laitier de haut fourneau ainsi que sur deux additions minérales encore peu étudiées dans la littéraire : le métakaolin et un sédiment de dragage calciné. Différentes formulations dérivées d'une formulation de BAP de parement de référence à base de CEM 1 ont été mises au point. Les résultats des essais mécaniques et physico-chimiques menés sur les différentes formulations montrent un effet plus ou moins important des additions sur le comportement mécanique au jeune âge et un effet positif certain à plus long terme. Les résultats des mesures de retrait endogène et de dessiccation de l'état frais (plastique) à l'état durci bien hydraté montrent que certaines additions augmentent le retrait de dessiccation des BAP (laitier et sédiment calciné) alors que d'autres le réduisent considérablement (le métakaolin). L'effet indéniable des additions sur l'amélioration de certains indicateurs de durabilité (diffusion des chlorures et perméabilité au gaz) et sur l'augmentation de leur sensibilité à la carbonatation a été quantifié. L'influence assez complexe des différentes additions est étudiée à la lumière des analyses physico-chimiques et microscopique. Enfin, une modélisation mésoscopique est développée et appliquée aux BAP en vue d'une une étude paramétrique. L'effet de la forme des granulats et de leur concentration sur le comportement global en compression et traction d'éprouvette de SAP ainsi que l'effet de l'endommagement mécanique sur l'évolution de la perméabilité sont étudiés. / Self-compacting concretes (SCC), developed several years ago are still considered as “•novel concrete" as their use remains modest although they have a strong development potential. This is mainly due to their higher cos, their sensitivity to segregation and cracking due to their high shrinkage and also due to the lack of information about their durability. SCCs are distinguished from ordinary concrete mainly by their high content of paste. The use of supplementary cementitious materials (SCM), grow increasingly for economic and environmental reasons. This thesis falls within this context and aims to contribute to the development of greener SCCs and to the study of their durability.Two industrial blended cements containing high amounts of SCM, slag cement CEM Ill and CEM V cement containing slag and fly ash as well as two mineral additions still little studied in the literature: metakaolin and calcined dredged sediment are used. Various SCC mixtures derived from a reference SCC based on CEM 1 cement were developed. The results of the mechanical, physical and chemical testing on the different formulations show a greater or lesser effect of SCM on the mechanical behavior at early age and some positive effect over the long term. The results of measurements of the autogenous and drying shrinkage from fresh state (plastic) to well hydrated state show that some SCMs increase the drying shrinkage of SCCs (slag and calcined sediment) while ethers significantly reduce its amplitude (metakaolin).The undeniable effect of SCMs on improving some durability indicators (chloride diffusion and gas permeability) and on increasing the sensitivity to carbonation was quantified. The rather complex influence of the different SCMs is studied in the light of physicochemical and microscopie analyzes. Finally, mesoscopic modeling is developed and applied to SCCs for a parametric investigation. The effect of the shape of aggregates and their concentration on the overall behavior in compression and tensile SCC specimen as well as the effect of the mechanical damage on the evolution of permeability are studied.

This Master thesis is focused on characterization of multicompound self-compacting heavy-weight mortars resistant against long lasting influence of ionizing radiation in the underground nuclear waste storage. It examines a specific combination of properties of heavy-weight concretes and self-compacting mortars while considering the ecological and energetic impact of their production, as well as the productibility of partial substitutions that do not have negative impact on material properties. The Experimental part provides a comprehensive overview of composition and properties of self-compacting heavy-weight mortars with varying percentages of cement-to-mortar ratio. Sample properties were evaluated based on mechanical test results, thermal analysis, differential scanning calorimetry, scanning electron microscopy and X-ray diffraction.

Deterioration of concrete structures due to the corrosion of embedded steel is a well-known universal problem. Norway with its numerous bridges, ports, offshore and floating structures along its coastline, is also encountered with corrosion degradation. The harsh environment of the Norwegian Sea regarding its low temperature, wind, and waves, makes the design and construction of marine structures more demanding. In recent years, usage of sustainable composite materials in the field of structural engineering has been rising. The usage of natural fibre reinforced polymer materials in the form of reinforcement bars or macro fibres with a low density, high strength, and excellent corrosion resistance, gives us better choices for the design and construction of marine structures. Our knowledge about the fibre reinforced self-compacting concrete has increased as a result of introducing it as a building material some decades ago. However, more research is still needed when it comes to the application of new types of fibres. This thesis is a result of this need, whereby the author has done two series of experimental programmes regarding the subject. In the first series, the flow characteristics of fresh state, conventional and self-compacting macro basalt fibre concrete were studied. In the second series, mechanical properties of high performance and medium strength macro basalt fibre concrete including the post-cracking behaviour, compressive strength and electrical resistivity were in focus. The findings were presented in three appended papers and the extended summary composing this thesis. Additionally, the thesis presents an overview of the design procedure of floating concrete structures and the possibility of using macro basalt fibre concrete via a case study. The author’s literature review shows that basalt fibres have an adequate resistance against alkali environment of the concrete matrix and corrosive environment of seawater. / <p>QC 20160607</p>

The present research is conducted to investigate the behaviour of elliptical tube columns filled with self-compacting concrete (SCC). In total, ten specimens, including two empty columns, were tested to failure. The main parameters investigated were the length and the sections of the columns, and the concrete compressive strength. Artificial Neural Network (ANN) model was developed to predict the compressive strength of SCC using a comprehensive database collected from different previous studies. The database was used to train and test the developed ANN. Moreover, parallel to the experimental works, a three dimensional nonlinear finite element (FE) model using ABAQUS software was developed to predict the behaviour of SCC elliptical tube columns. The proposed ABAQUS model was verified against the current experimental results. The experimental results indicated that the failure modes of the SCC filled elliptical steel tube columns having large slenderness ratios were dominated by global buckling. Moreover, the composite columns possessed higher critical axial compressive capacities compared with their hollow section companions due to the composite interaction. However, due to the large slenderness ratio of the test specimens, the change of compressive strength of concrete core did not show significant effect on the critical axial compressive capacity of concrete filled columns although the axial compressive capacity increased with the concrete grade increase. The comparisons between the axial compressive load capacities obtained from experimental study and those predicted using simple methods provided in Eurocode 4 for concrete-filled steel rectangular tube columns showed a reasonable agreement. The proposed three dimensional FE model accurately predicted the failure modes, the load capacity and the load-deflection response of the columns tested. The experimental results, analysis and comparisons presented in this thesis clearly support the application of self-compacting concrete filled elliptical steel tube columns in construction engineering practice.

The present research is conducted to investigate long term (more than two years) free and confined drying shrinkage magnitude and behaviour of self-compacting concrete (SCC) and compare with normal concrete (NC). For all SCCs mixes, Portland cement was replaced with 0-60% of fly ash (FA), fine and coarse aggregates were kept constant at 890 kg/m3 and 780 kg/m3, respectively. Two different water binder ratios of 0.44 and 0.33 were examined for both SCCs and NCs. Fresh properties of SCCs such as filling ability, passing ability, viscosity and resistance to segregation and hardened properties such as compressive and flexural strengths, water absorption and density of SCCs and NCs were also determined. Experimental results of free drying shrinkage obtained from this study together with collected comprehensive database from different sources available in the literature were compared to five existing models, namely the ACI 209R-92 model, BSEN-92 model, ACI 209R-92 (Huo) model, B3 model, and GL2000 model. To assess the quality of predictive models, the influence of various parameters (compressive strength, cement content, water content and relative humidity) on the drying shrinkage strain are studied. An artificial neural network models (ANNM) for prediction of drying shrinkage strains of SCC was developed using the same data used in the existing models. Two ANNM sets namely ANNM1 and ANNM2 with different numbers of hidden layer neurones were constructed. Comparison between the results given by the ANNM1 model and the results obtained by the five existing predicted models were presented. The results showed that, using up to 60% of FA as cement replacement can produce SCC with a compressive strength as high as 30 MPa and low drying shrinkage strain. SCCs long-term drying shrinkage from 356 to 1000 days was higher than NCs. Concrete filled elliptical tubes (CFET) with self-compacting concrete containing FA up to 60% are recommended for use in construction in order to prevent confined drying strain. ACI 209R-92 model provided a better prediction of drying shrinkage compared with the other four models. However, a very high predictability with high accuracy was achieved with the ANNM1 model with a mean of 1.004. Moreover, by using ANNM models, it is easy to insert any of factors effecting drying shrinkage to the input parameters to predict drying shrinkage strain of SCC. / Ministry of Higher Education, Libya

Yes / The test results on eight two-span deep beams made of self-compacting concrete (SCC) are presented and discussed in this paper. The main parameters investigated were the shear span-to-depth ratio, and the amount and configuration of steel reinforcement. All beams failed due to a major diagonal crack formed between the applied mid-span load and the intermediate support separating the beam into two blocks: the first one rotated around the end support leaving the other block resting on the other two supports. Both concrete compressive strength and web reinforcement had a major effect in controlling the shear capacity of the beams tested. For the shear span-to-depth ratio considered, the vertical web reinforcement had more influence on the shear capacity of the specimens than the horizontal web reinforcement. The shear provisions of the ACI 318M-11 are unconservative for most of the beams tested. Comparisons of test results with the strut-and-tie model (STM) suggested by ACI 318M-11, EC2 and CSA23.4-04 showed that the predictions are reasonable for continuous deep beams made with low and medium compressive strength. Although the equation suggested by ACI 318M-11 is very simple, its prediction is more accurate than the STM suggested by different design codes. / This research investigation was funded by the Higher Education Ministry in The Libyan Government.

Yes / The current design codes, such as ACI 318-14, EC2 and CSA23.3-04, in addition to previous research investigations suggested different expressions for concrete effectiveness factor for use in limit state design of concrete structures. All these equations are based on different design parameters and proposed for normal concrete deep beams. This research evaluates the use of different effectiveness factor equations in the upper and lower bond analyses of continuously-supported self-compacting concrete (SCC) deep beams. Moreover, a new effectiveness factor expression is suggested to be used for upper and lower bound solutions with the aim of improving predictions of the load capacity of continuously-supported SCC deep beams. For the range of deep beams considered, the strut-and-tie method with the proposed effectiveness factor formula achieved accurate predictions, with a mean of 1.01, a standard deviation of 6.7% and a coefficient of variation of 6.8%. For the upper-bound analysis, the predictions of the proposed effectiveness factor equation were more accurate than those of the formulas suggested by previous investigations. Overall, although the proposed effectiveness factor achieved very accurate predictions, further validation for the proposed formula is needed since the only data available on continuous SCC deep beams are those collected form the current study.

yes / This paper introduces a novel symbolic regression approach, namely biogeographical-based programming (BBP), for the prediction of elastic modulus of self-compacting concrete (SCC). The BBP model was constructed directly from a comprehensive dataset of experimental results of SCC available in the literature. For comparison purposes, another new symbolic regression model, namely artificial bee colony programming (ABCP), was also developed. Furthermore, several available formulas for predicting the elastic modulus of SCC were assessed using the collected database. The results show that the proposed BBP model provides slightly closer results to experiments than ABCP model and existing available formulas. A sensitivity analysis of BBP parameters also shows that the prediction by BBP model improves with the increase of habitat size, colony size and maximum tree depth. In addition, among all considered empirical and design code equations, Leemann and Hoffmann and ACI 318-08’s equations exhibit a reasonable performance but Persson and Felekoglu et al.’s equations are highly inaccurate for the prediction of SCC elastic modulus.

This paper presents the experimental results and observation of elliptical concrete filled tube (CFT) columns subjected to axial compressive load. A total of twenty-six elliptical CFT specimens including both stub and slender composite columns are tested to failure to investigate the axial compressive behaviour. Various column lengths, sectional sizes and infill concrete strength are used to quantify the influence of member geometry and constituent material properties on the structural behaviour of elliptical CFT columns. As there is no design guidance currently available in any Code of Practice, this study provides a review of the current design rules for concrete filled circular hollow sections in Eurocode 4 (EC4). New equations based on the Eurocode 4 provisions for concrete filled circular hollow sections were proposed and used to predict the capacities of elliptical CFT columns.