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Strength and hydraulic conductivity characteristics of roller compacted concreteZafar, Saleem. January 1997 (has links)
Thesis (M.S.)--Ohio University, August, 1997. / Title from PDF t.p.
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Bond shear strength of a rigid pavement system with a roller compacted concrete baseKreuer, Blake R. January 2006 (has links)
Thesis (M.S.)--Cleveland State University, 2006. / Includes bibliographical references (p. 102-106).
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Experimental studies and modeling of the roller compaction of pharmaceutical powders /Cunningham, John C. Zavaliangos, Antonios. January 2006 (has links)
Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 221-234).
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Bonding Efficiency Of Roller Compacted Concrete With Different Bedding MixesOzcan, Sinan 01 December 2008 (has links) (PDF)
Roller Compacted Concrete (RCC) has rapidly evolved from a concept to a material and a process which is used throughout the world for faster and more economical construction of dams. Currently, there are more than 250 RCC dams, completed or under construction, in the world. On the other hand, currently, there are only two RCC dams completed (Suç / ati and Cindere Dams) and two under construction (Beydag and Ç / ine Dam) in Turkey.
RCC dams are constructed in a series of compacted layers usually 30 cm in thickness. Therefore, appropriate bonding of successive layers is important and as a result, in between successive layers a bedding mix is often used to fill the surface voids in both the compacted layer below and the covering layer above, as well as to bond the two successive layers together.
This study presents an experimental investigation on the bonding efficiency of RCC with different bedding mixes. The Beydag Dam RCC mixture was taken as the model for the preparation of laboratory-made RCC specimens. In the experimental study, 15 cm cubic specimens were prepared in two layers. Each layer was compacted using an electro pneumatic demolition hammer for 30 seconds. Four different time intervals between placement and compaction of two successive layers and two different bedding mix types were the selected cases for investigation. While preparing the specimens, the second layer was placed and compacted 0, 4, 8, 12 and 16 hours after the first layer was compacted. In between the two layers, two types of bedding mixes are placed in between previously compacted and freshly placed layer for joint treatment. One of the bedding mixes, having 200 kg/m3 cement content is termed poor while other one is termed rich having 400 kg/m3 cement content.
RCC specimens are then subjected to compressive strength, splitting tensile strength and permeability tests. As a result of the experimental program, it was found that / a rich bedding mix was a more effective bonding agent between compacted RCC layers than the poor bedding mix for all time intervals between layers. Furthermore, it was concluded that bonding efficiency of RCC is not too dependent on time interval between layer compactions up to 16 hours. Finally, splitting tensile strength and sorptivity tests are shown to be applicable test methods for determination of bonding efficiency of RCC specimens if there is a definite bedding layer in between freshly placed and formerly compacted RCC.
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Construction of a dam over the Escartana gully close to Albacete, Spain.Navarro Lérida, Alfonso January 2011 (has links)
The main aim of this Master Thesis is the design of several hydraulic structures to decrease as much as possible the huge flooding caused by the Escartana gully which drains its water towards the city of Albacete (Spain) and its surrounding areas, affecting to their inhabitants; and causing huge material damages in residential and industrial areas, and loss of crops in nearby farmland. Some alternatives such as embankment dams with or without drainage systems inside the dam body and a roller-compacted concrete (RCC) dam have been proposed to be built, being necessary to carry out a multicriteria analysis in order to decide which alternative has the best fit according to the analyzed features of the region. The alternative chosen to be developed was the RCC dam for the advantages of this typology, currently in development and implantation in some countries like Spain. For this reason, a RCC dam is planned to be built some kilometers upstream of these areas, with the objective of controlling the future floods coming from this watershed by decreasing its peak flow. In order to increase the beneficial effects of the construction of the dam, a channel downstream is also designed to drain the discharged overflows by the drainage systems of the dam towards a natural endorheic area, the Salobral Lagoon (currently dried-up), located 13 kilometers downstream of the dam’s location. This lagoon is connected hydraulically to the drainage network of Albacete by means of the Salobral channel and due to its huge storage capacity, it allows to reduce substantially the peak flows over the Salobral channel avoiding the dangerous flooding and potential damages caused by them. As a result of the projected hydraulic structures, Albacete and its surrounding areas would increase substantially their protection against the floods coming from the Escartana watershed.
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Designing Roller compacted concrete (RCC) dams / Dimensionering av RCC (Roller Compacted Concrete) dammarAl Baghdady, Shayma, Khan, Linnea January 2018 (has links)
Concrete is the most common building material in the world and it consists of aggregates,cement and water that harden over time, it is also known as a composite material. The use ofconcrete is very versatile due to its resistance to wind and water and its ability to withstandhigh temperature. These qualities make concrete a suitable building material for largestructures such as dams.A dam is a huge construction that needs massive amount of concrete to build it with and thatleads to high cost, so alternative methods should be considered to minimize the cost ofconstructing the dams. One method is building the dams with Roller Compacted Concrete(RCC), which by definition is a composite construction material with no-slump consistency inits unhardened state and it has achieved its name from the construction method. The definitionfor a no-slump consistency is a freshly mixed concrete with a slump less than 6 mm. TheRCC is placed with the help of paving equipment and then it is compacted by vibrating rollerequipment. The RCC ingredients are the same as for the conventional concrete but it hasdifferent ratios in the materials that are blended to produce the concrete. It differs when itcomes to aggregates because both similar aggregates used in conventional concrete oraggregates that do not fulfill the normal standards can be used in the RCC mixtures. Thismeans, for example that aggregates found on the construction site can be used for the RCC.Compared to when constructing a conventional concrete dam, which is usually built in largeblocks, the RCC dam are usually built in thin, horizontal lifts, which allows rapidconstruction. This reduces the amount of formwork, but also the demand for man-hours areless due to the usage of machines for spreading and compacting, ultimately making it acheaper method. Building with RCC has become very popular around the world because of itsadvantages and new methods have been developed over the past two decades, adapted to theexperience gained after each project. All RCC dams that has been built, usually faceschallenges both during and after construction, and it includes everything from temperaturevariations, cracks to leakage.The main purpose of this master thesis is to create a guideline for how to design and constructdams with RCC and the idea is to be able to use it as a basis for future dams. Therequirements of Eurocode 2 and RIDAS are the basis of the criteria that the dam must fulfilland information of what is expected of the RCC is presented in this thesis. Furthermore anexample for design of an existing embankment dam to an RCC dam has been presented in thisthesis. The embankment dam needs to be rebuilt in order to increase the safety of the dam andthe goal of the case study was to determine the dimensions of the new RCC dam. / Betong är det vanligaste byggmaterialet i världen och det är ett material som består av ballast,cement och vatten som härdas över tiden, även känt som ett komposit material. Användningenav betong är mycket mångsidig tack vare dess motståndskraft mot vind och vatten och dessförmåga att motstå höga temperaturer. Dessa egenskaper gör betong ett lämpligt byggmaterialför stora strukturer som dammar.En dam är en enorm konstruktion som kräver massiva mängder av betong för att bygga denmed och det leder till höga kostnader, därför bör alternativa metoder övervägas för attminimera dessa. Ett förslag till en metod är att bygga dammar med Roller CompactedConcrete (RCC), som per definition är ett komposit material med ett sättmått på mindre än 6mm i sitt ohärdade tillstånd. RCC har erhållit sitt namn från sin byggmetod, då den sprids medhjälp av utrustning för att lägga vägar och sedan kompakteras den med en traktordrivenvibratorvält. Ingredienserna för RCC är samma som för konventionell betong, men den storaskillnaden utgörs av att det är olika mängd-förhållanden av de material som blandas för attproducera denna betong. Det skiljer sig också när det gäller ballasten, eftersom både liknandeballast som används i konventionell betong eller ballast som inte uppfyller de normalastandarder kan användas för RCC. Det betyder att exempelvis, ballast som man erhåller påbyggarbetsplatsen kan användas för att producera RCC.I jämförelse med när man bygger en traditionell betongdamm, som vanligen byggs i storablock, så bygger man oftast en RCC damm i horisontella lager vilket ger möjligheten försnabbt byggande. Detta reducerar behovet av att använda gjutformar, men även antaletmantimmar på grund av användningen av maskiner för spridning och kompaktion. De härfaktorerna gör det till en billigare metod. RCC dammar har blivit populärt att bygga runt om ivärlden på grund av dess fördelar och nya metoder har utvecklats under de senaste 20 årenanpassade efter erfarenheten man har erhållit efter varje projekt. Alla RCC dammar sombyggts stöter ofta på utmaningar både under och efter byggandet och det har med, allt fråntemperatur variationer, sprickor, och läckage, att göra.Huvudsyftet med det här examensarbetet är att skapa en guide för hur man designar ochbygger en RCC damm och tanken är att man ska kunna använda den som en grund förframtida dammbyggen. Kraven från Eurokod 2 och RIDAS är grunden för kriterierna somdammen ska uppfylla och information om vad som förväntas av RCC är presenterat. Enfallstudie har gjorts, där ett exempel på en design för en RCC damm som ska ersätta enbefintlig fyllningsdamm i Hylte är presenterad. Fyllningsdammen är i behov av ombyggnationför att höja säkerheten av dammen och målet med fallstudien är att avgöra dimensionerna förden nya RCC dammen som ska placeras där.
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Strength and hydraulic conductivity characteristics of roller compacted concreteZafar, Saleem January 1997 (has links)
No description available.
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Three Dimensional Dynamic Response Of A Concrete Gravity DamYilmazturk, Sema Melek 01 January 2013 (has links) (PDF)
Hydroelectric power is a commonly used alternative source of energy in developing countries. In this regard, concrete gravity dams are the most preferred dam type especially with the developments in the engineering industry. Roller compacted concrete became more popular in dam construction due to its advantages of speed and economy. Several methods are used for the design of concrete gravity dams by analyzing the dam response under static and dynamic loads. This study provides three dimensional linear dynamic analysis of roller compacted concrete gravity dam with a complete dam-foundation-water interaction by using EACD-3D-08 program. Foundation flexibility was included with damping and mass using boundary elements. Three dimensional solid elements were used for the idealization of the dam and water with using finite element methods. Compressibility of water with reservoir absorption was studied. In the light of USACE, performance criteria of linear analyses were assessed. Parametric study was conducted to determine the most influential parameters on the dam response. The importance and necessity of three dimensional analyses were investigated by comparing with linear two dimensional analyses. Linear analyses were then compared with three dimensional nonlinear analyses. In conclusion, the realistic dam seismic response can only be obtained by using three dimensional linear analyses with full interaction of dam-foundation-water.
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Predicting Long Term Strength Of Roller Compacted Concrete Containing Natural Pozzolan By Steam CuringAslan, Ozlem 01 September 2006 (has links) (PDF)
Roller Compacted Concrete (RCC) is new technology gaining popularity in the recent years due to its low cost, rapid construction, and using opportunity of by-products. RCC is widely used in the world. However, the use of RCC has been restricted to construction of few cofferdams, and limited to local use in dam construction up to date.
In this thesis, two types of cement, two types of natural pozzolan, aggregates with varying gradations, and a type of water reducing chemical admixture were used. Prior to carrying out the tests, the chemical and physical properties of materials were determined. Additionally, steam curing was applied to the test specimens in order to get long term compressive strength at early ages. Differences between steam cured specimens and normal cured specimens have been discussed in the discussion part.
In the study, the results indicate that usage of water reducing chemical admixture improves compressive strength of RCC. Moreover, it is revealed that usage of fine material is essential to obtain desired results since the amount of cementitious materials is considerably low in RCC. Steam curing is known as its property of providing long term compressive strength at early ages. It was observed that application of steam curing in CEM I type cement used RCC mixtures generated expected results. However, in CEM IV type cement used RCC mixtures compressive strength results did not behave in the same manner.
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Optimisation des cendres volantes et grossières de biomasse dans les bétons compactés au rouleau et dans les bétons moulés à secLessard, Jean-Martin January 2016 (has links)
Résumé : Depuis le début du XXe siècle, la production de bétons secs représente une industrie importante pour le développement des infrastructures en bétons compactés au rouleau notamment pour la construction de barrages, de digues, de pavages, et les bétons moulés à sec pour la pré-fabrication de blocs de maçonnerie, de briques, de pierres de pavé, etc. La durabilité de celles-ci peut être améliorée en réduisant leur consommation de ciment Portland et de granulats naturels en utilisant, respectivement, des ajouts cimentaires et des matériaux granulaires alternatifs. D’ailleurs, beaucoup de sous-produits industriels et autres ajouts cimentaires alternatifs ne respectant pas les exigences pour le béton conventionnel ont été utilisés avec succès dans ce type de béton. Les cendres de biomasse sont des sous-produits prometteurs pour les applications de bétons secs. Ces cendres sont obtenues dans une centrale de cogénération de l’industrie des pâtes et papiers suite à la combustion de leurs boues de traitement des eaux usées, de leurs boues de désencrage, et autres résidus de bois. Les cendres volantes de biomasse (CVB) ont une finesse similaire à celle du ciment et elles possèdent aussi un potentiel de réactivité pouzzolanique. Elles peuvent donc remplacer une partie du ciment utilisé dans la formulation de bétons. Les cendres grossières de biomasse (CGB) ont une granulométrie voisine de celle d’un sable fin. Elles peuvent donc être valorisées en remplaçant une partie des granulats naturels utilisés dans les formulations de bétons. Bien que les propriétés physico-chimiques et les interactions cimentaires de celles-ci soient étudiées depuis le début des années 2000, très peu d’applications commerciales ou industrielles ont été développées. Ce projet de recherche vise l’étude et l'optimisation des CVB comme ajout cimentaire alternatif et des CGB comme granulats fins alternatifs dans la production de bétons compactés au rouleau (BCR) et à la paveuse (BCP) pour des applications de pavages industriels et dans la production de bétons moulés à sec (BMS) pour des applications de préfabrication de pierres de pavé. Pour chacune de ces applications, des formulations incorporant un taux de substitution jusqu'à 30% du ciment par des cendres volantes et jusqu’à 100% du sable par des cendres grossières ont été réalisées. Ces travaux d’optimisation ont été effectués avec des bétons à rap-port eau-liant de 0,32, 0,35 et 0,37. Les propriétés à l’état frais (maniabilité et consistance), à l’état durci (résistance à la compression, à la flexion et à la traction), et de durabilités (absorption à l’eau, vides perméables et résistivité électrique) jusqu'à 91 jours ont été mesurées pour tous les mélanges de béton. Le rapport eau-liant, la teneur en pâte et les taux de remplacement optimaux ont également été combinés et optimisés afin de valoriser un maximum de cendres de biomasse, volantes et grossières, dans une seule formulation. Les résultats des mélanges de BCR fabriqués en laboratoire avec 10% et 20% de CVB et combinés à 50% de CGB ont respectivement montré des maniabilités désirées et des résistances à la flexion supérieures aux limites prescrites par les devis techniques pour une utilisation pratique de 23% et 29%. Ces deux mélanges donc ont été sélectionnés pour évaluer leur comportement in situ à l’aide de la construction d'une dalle de stockage de 792 m² par 300 mm d'épaisseur à l'aide de pratiques courantes. Des carottes ont été prélevées dans la dalle à 28 et 308 jours. La résistance à la compression des noyaux à l'âge de 308 jours a atteint 33 et 30 MPa pour les deux mélanges testés, respectivement. Les BMS fabriqués avec 5%, 10%, ou 15% CVB et 25% de CGB peuvent atteindre un indice de compaction de 99% avec un travail de compaction inférieur à celui spécifié par les fabricants de pierre de pavés. L'utilisation des CVB et CGB entraîne une faible diminution de la résistance à la compression, mais présente des valeurs de perméabilité et d’absorption à l’eau très faibles et inférieures aux exigences requises les normes (près de 5%). Ces travaux de recherche présentent un débouché potentiel à la valorisation des cendres volantes et grossières de biomasse issues de l’industrie des pâtes et papiers dans les bétons secs comme ajout cimentaires ou granulats fins. Cette approche peut offrir une contribution significative pour la réduction des émissions de gaz à effet de serre associés à la production de ce type de béton et dans les gestions des matières résiduelles de l’industrie des pâtes et papiers. / Abstract : Since the early twentieth century, the production of dry concrete is an important industry for infrastructure development including the construction of dams, core dikes, and pavements using roller-compacted concrete, and precast masonry blocks, bricks, pavers using dry-cast concrete. The sustainability thereof can be improved by reducing its consumption of Portland cement and natural aggregates using cementitious supplementary cementitious materials and alternative granular materials, respectively. Moreover, many industrial by-products and other mineral additions not meeting the requirements for conventional concrete have been success-fully used in such concrete.
The biomass ashes are promising supplementary materials for dry concrete applications. These ashes are produced in a cogeneration plant of the pulp and paper industry following the burn-ing of their wastewater treatment sludge, their de-inking sludge, and other wood residues. The biomass fly ash (BFA) have a similar finesse in the cement and they also have a potential poz-zolanic reactivity. They may therefore replace part of the cement used in concrete formula-tions. The biomass bottom ashes (BBA) have a particle size close to that of a fine sand. They can be use to replace a portion of the natural aggregates. Although the physicochemical proper-ties and interactions with cement have been studied since the early 2000s, very few commer-cial or industrial applications have been developed.
This research project aims at studying and optimizing the BFA content as an alternative sup-plementary cementitious materials and the BBA content as an alternative fine aggregates in the production of roller-(RCC) and paver-compacted concrete (PCC) for industrial pavements and dry-cast concrete (DCC) for the manufacture of pavers. Formulations incorporating substitu-tion rates of cement up to 30% by BFA and of the sand up to 100% by BBA were evaluated for each of the mentioned applications. This optimization work was carried out with concrete water-to-binder ratio (w/b) of 0.32, 0.35 and 0.37. The fresh properties (workability and com-pactness), hardened properties (compressive strength, flexural strength and splitting-tensile strength) and transport properties (water absorption, permeable voids and electrical resistivity) up to 91 days were measured for all concrete mixtures. The optimal w/b, paste content and replacement rates were also combined and optimized in order to maximize the biomass fly and bottom ashes content, in a single formulation.
The results of concrete mixtures made with 10% and 20% BFA with 50% BBA showed 23% and 29% higher flexural strength than the limits required for practical use of RCC, respective-ly. These two RCC mixtures were selected for the assessment of in situ behaviors through the construction of a storage slab of 792 m² per 300 mm thick using standard practices. Core sam-ples were cut from the slabs at age of 28 and 308 days for follow-up of the concrete behavior with time. The compressive strength of the cores at an age of 308 days reached 33 and 30 MPa for the two tested mixtures, respectively.
The DCC mixtures made with 5%, 10%, or 15% BFA and 25% of BBA can reach a compact-ness index of 99% with a compaction work lower than specified by the Standards. The use of the BFA and BBA lead to small decrease of the compressive strength, however they can result in very low permeability and water absorption values lower than required by the specifications (close to 5%).
This research presents a potential market for recycling biomass fly and bottom ashes from the pulp and paper industry in dry concrete as alternative supplementary cementitious materials or fine aggregates. This approach can provide a significant contribution to reduce greenhouse gas emissions associated with the production of this type of concrete and with the managements of by-products from the pulp and paper industry.
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