Concrete bridges in Texas have developed large cracks in bent caps and pretensioned trapezoidal bridge girders. The bridges show premature concrete deterioration due to alkali-silica reaction (ASR) and delayed ettringite formation (DEF). There is concern that deterioration due to ASR/DEF may lead to a loss of structural capacity. However, there are no quantitative guidelines to relate the level of concrete deterioration due to ASR/DEF to structural performance. Using such guidelines, the need for rehabilitation of beams with ASR/DEF cracking can be assessed. The goal of this research was to determine the shear capacity of pretensioned trapezoidal box girder specimens exhibiting varying degrees of ASR and/or DEF cracking and to use the shear testing results to evaluate the severity of the problem that may exist in Texas bridge structures. To achieve this goal, beams that were severely deteriorated due to ASR/DEF over a period of more than ten years were transported to the University of Texas for testing to failure. Both severely deteriorated and uncracked beams were tested in shear. The test results were used to evaluate the shear performance of trapezoidal box beams affected by ASR/DEF. In addition, three different types of forensic analyses were conducted on the beams to understand the nature of the ASR/DEF cracks and severity of the deterioration. After testing, it is found that the shear capacity of the test specimens was not significantly reduced even with heavy ASR/DEF cracking. Assessment using current US design provisions for bridges or buildings (ACI 318-08 and AASHTO LRFD 2008) and the proposed provision from an earlier project (TxDOT Project 5253) yielded conservative estimates of strength. Results from forensic analyses provided a qualitative indication of ASR/DEF damage but did not correlate with the observed levels of ASR/DEF deterioration. / text

Across the State of Texas and many other areas of the world, relatively young concrete structures have developed signs of premature concrete deterioration. Large cracks form on the surface of the concrete due to expansive forces from alkali-silica reaction (ASR) and delayed-ettringite formation (DEF). The goal of this project is to assess the effect of ASR/DEF on the trapezoidal box beam bridges in the US 59 corridor and Katy Central Business District (CBD) HOV lanes in Houston, TX. Five dapped-end beams were rejected during the casting process and have been in storage at a local precast yard for nearly fifteen years. These beams have been subject to accelerated deterioration and represent the potential severity of the ongoing ASR/DEF distress within the dapped end regions of the in-service trapezoidal box beams. The results from five load tests, corresponding strut-and-tie models, and forensic investigation are used to provide insights into the relationship between the severity of the deterioration and the capacity margin. / text

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-06-29T12:25:26Z No. of bitstreams: 2 Dissertação - Geovanne Caetano Gomes - 2017.pdf: 4000475 bytes, checksum: 9ebf09d429582174011cbfd00331c5d4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-10T14:15:56Z (GMT) No. of bitstreams: 2 Dissertação - Geovanne Caetano Gomes - 2017.pdf: 4000475 bytes, checksum: 9ebf09d429582174011cbfd00331c5d4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-10T14:15:56Z (GMT). No. of bitstreams: 2 Dissertação - Geovanne Caetano Gomes - 2017.pdf: 4000475 bytes, checksum: 9ebf09d429582174011cbfd00331c5d4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-05-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Among the several deleterious actions may attack concrete elements, is the alkali-aggregate reaction (AAR), which affects, mainly, structures of dams, bridges and foundations, where the alkali-silica reaction (ASR) is the most common. One of the main challenges regarding the prediction of this phenomenon is the development of models that may predict damage specific for this reaction, which constitute the theme of this research. Firstly, a systematic literature review was conducted with respect to the models developed, with the organization and classification of the data found, presenting a clear and detailed state-of-art. Therefore, the studies published in journals in the last five years (2012-2016) were selected, in order to conduct their categorization regarding the scale and nature of the analysis, type of modeling, and the software necessary to execute the simulations, besides the summarizing, grouping and analysis of the information concerning the input data necessary to the execution of each modeling, as well as the results generated by each one of them. The models which do not predict damage, i.e. general models that simulate the ASR, were investigated to verify their contribution to a better understanding of the chemical and physical processes that occur in the concrete affect by the reaction. Finally, it was verified that the models analyzed are based on different theories and methods of analyses, demanding distinct input data and generating heterogeneous output data, which are meticulously explained in this paper. / Dentre as várias ações deletérias que podem atacar elementos de concreto tem-se a reação álcali-agregado (RAA), a qual afeta principalmente as estruturas de barragens, pontes e fundações, sendo a reação do tipo álcali-sílica (RAS) a mais recorrente nelas. Um dos principais desafios no que tange à predição desse fenômeno é o desenvolvimento de modelos de previsão de dano específicos dessa reação, constituindo-se o tema da presente pesquisa. A priori, executou-se uma revisão sistemática da literatura a respeito dos modelos desenvolvidos, com a organização e classificação dos dados encontrados, apresentando-se o estado da arte de forma clara e detalhada. Em seguida, foram elencados os trabalhos publicados em periódicos indexados nos últimos cinco anos (2012-2016), executando-se a categorização dos modelos quanto à escala e natureza de análise, tipo de modelagem, e softwares necessários para executar as simulações, além da sintetização, agrupamento e análise de informações concernentes aos dados de entrada necessários para a execução de cada modelação, bem como dos resultados gerados por elas. Para os modelos que não preveem dano, isto é, modelos gerais que simulam a RAS, investigou-se sua contribuição para o melhor entendimento dos processos químico-físicos que ocorrem no concreto afetado por ela. Verificou-se, assim, que os modelos analisados são pautados em diferentes teorias e métodos de análise, demandando dados de entrada distintos e gerando dados de saída heterogêneos, os quais são discriminados minuciosamente neste trabalho.

Concrete has proven to be, by far, one of the most reliable materials for the construction of critical infrastructure. However, despite its structural capacity, concrete members are susceptible to damage mechanisms that may decrease its performance and durability throughout its service life. One such mechanism is alkali-silica reaction (ASR), which takes place when unstable siliceous phases present in coarse or fine aggregates react with the alkali hydroxides from the concrete pore solution, generating a secondary product (i.e., ASR gel); this product swells upon moisture uptake from the surrounding environment, leading to cracking and expansion of the affected concrete. In severe cases of ASR-affected infrastructure, structural safety could become a problem, and thus requiring the demolition of affected members. It is, therefore, necessary to adopt effective protocols for the diagnosis and prognosis of aging infrastructure, to ensure its performance over time along with properly planning for rehabilitation strategies, whether required. This work presents a two-stage case study of the S.I.T.E. building at the University of Ottawa for the diagnosis and prognosis of ASR-affected members (i.e., columns) after nearly 20 years in service. The diagnosis phase was conducted with the aim of evaluating the cause and extent of distress and interpreting its impact on the performance of the affected structure. First, a visual inspection was conducted to evaluate potentially damaged members, in order to select the best location for core-drilling. Once ASR was confirmed through petrographic examination, specimens were evaluated through the multi-level assessment (i.e., coupling of microscopic and mechanical assessment). A range of damage was discovered among the examined columns (i.e., 0.03%, 0.05%, and 0.08% expansion). Moreover, evidence of developing freeze and thaw (FT) damage was discovered in columns with greater levels of expansion, raising future concerns regarding the durability and serviceability of members affected by this coupling of damage (i.e., ASR+FT). For the second stage of this project (i.e., prognosis), a novel ASR semi-empirical model was developed with the aim of predicting future ASR-induced expansion and damage in the S.I.T.E. building. The above model was developed and validated (using ASR exposure site data) through the coupling of existing chemo-mechanical macro-models, which were used to predict material behaviour on the structural scale, and novel mathematical relationships for the prediction of anisotropy in the columns. Moreover, the use of the multi-level assessment to predict the mechanical implications of predicted distress was found to enhance the model’s capacity for prognosis and demonstrated important potential for the accurate prediction of multi-level damage in the S.I.T.E. columns.

Les ciments sulfoalumineux sont des liants hydrauliques qui, jusqu’aujourd’hui ne sont pas normalisés et ne possèdent donc pas une composition fixe. La teneur en ye’elimite – la phase principale de ce ciment- peut varier de 5 à 70 %. Or la composition du ciment sulfoalumineux (la composition du clinker ainsi que le pourcentage de gypse ajouté) est un paramètre critique qui contrôle sa réactivité, ses performances mécaniques, ainsi que sa durabilité. L’objectif principal de cette thèse est donc l’étude de l’influence de la composition des ciments sulfoalumineux sur leurs propriétés techniques, telles que les performances mécaniques et durabilité. Trois axes principaux ont été abordés. Tout d’abord une étude de l’influence de la composition du ciment sulfoalumineux (25-75 % en masse de ye’elimite) sur ses propriétés hydrauliques et mécaniques ainsi que sur la valeur limite en élément trace (Zn) a été menée. Dans ce but trois ciment sulfoalumineux (25, 50 et 75 % en masse de ye’elimite) ont été synthétisés. Ensuite l’effet de la variabilité de ce ciment sur sa durabilité dans l’eau pure et sulfatée a été investigué par rapport à un ciment sulfoalumineux commercial. Enfin, une étude des potentialités du ciment sulfoalumineux commercial à inhiber la réaction alcali silice dans les mortiers, lors de l’utilisation d’un granulat réactif (Silex), a été conduite. Il en résulte de cette étude qu’une augmentation de taux de ye’elimite dans le ciment sulfoalumineux engendre une augmentation des performances mécaniques. La valeur limite en Zn est de 0,3 % indépendamment de la composition du ciment sulfoalumineux. Par contre cette dernière influence la durabilité de ces ciments. Les résultats révèlent que même si la formulation contenant 75 % en ye’elimite confère les meilleures performances mécaniques, sa durabilité était la plus faible due à l’absence de stratlingite dans sa matrice cimentaire. Enfin, l’utilisation du ciment sulfoalumineux présente des bonnes potentialités à inhiber la réaction alcali silice. / Sulfoaluminate cements are hydraulic binders that, until today, are not standardized and therefore do not have a fixed composition. The content of ye'elimite - the main compound of this cement - can vary from 5 to 70 %. However, the composition of sulfoaluminate cement (clinker composition as well as the percentage of added gypsum) is a critical parameter that controls its reactivity, mechanical performance, as well as its durability. The main objective of this thesis is to study the influence of sulfoaluminate cements composition on their technical properties, such as mechanical performances and durability. Three main axes were discussed in this work. First, the influence of the sulfoaluminate cement composition (25-75 wt. % of ye'elimite) on its hydraulic and mechanical properties, as well as on the threshold limit of Zn, was studied. For this purpose three sulfoaluminate cements (25, 50 and 75 wt. % of ye'elimite) were synthesized. Then the effect of the variability of this cement on its durability in pure and sulphated water was investigated compared to a commercial sulfoaluminate cement. Finally, a study of the potentialities of commercial sulfoaluminate cement to inhibit the alkali silica reaction in mortars, when using a reactive aggregate (flint), was conducted. This study reveals that an increase in ye'elimite content in the sulfoaluminate cement increases the mechanical performance. The threshold limit of Zn is 0.3 % independently of the sulfoaluminate cement composition. Contrariwise, the sulfoaluminate cement composition influences the durability of these cements. Although the formulation containing 75 % of ye’elimite gives the best mechanical performances, its durability was lowest due to the absence of stratlingite in its cement matrix. Finally, the use of sulfoaluminate cement has good potential towards the inhibition of the alkali silica reaction.

This thesis deals with deterioration observed in cement-concrete cover (CBK) for three selected road sections of highways in the Czech Republic. The main objective was to determine whether concrete failure arose due to alkali-silica reaction, or other mechanism. The deterioration of concrete failure was observed in the macroscopic and microscopic scale. The mostly macroscopically observed deterioration of the concrete were cracks breaking the surface and inner parts of concrete. In micro- scale the microcracks and alcali-silica gels were observed. The CBK deterioration was quantitatively determined by three main parameters: specific length of microcracks on the CBK surface, specific length of microcracks in the drill cores and volume of alcali-silica gels and microcracks in thin sections. According to these indicators it was possible to distinguish two different types of CBK deteriorations. (1) Degradation mainly associated by alkali-silica reaction (observed on highways D11 - Vrbová Lhota and D1) and (2) degradation connected with another mechanism (cycles of freezing and thawing, mechanical degradation) was observed on the highway D5.

Recycled concrete is among the rising eco-friendly construction materials which helps to reduce waste and the need for new natural resources. However, such concrete may present previous deterioration due to, for instance, alkali-silica reaction (ASR), which is an ongoing distress mechanism that may keep being developed in the recycled material. This work aims to evaluate the potential of further distress and crack development (i.e. initiation and propagation) of AAR-affected RCA concrete in recycled mixtures displaying distinct past damage degrees and reactive aggregate types. Therefore, concrete specimens incorporating two highly reactive aggregates (Springhill coarse aggregate and Texas sand) were manufactured in the laboratory and stored in conditions enabling ASR development. The specimens were continuously monitored over time and once they reached marginal (0.05%) and very high (0.30%) expansion levels, they were crushed into RCA particles and re-used to fabricate RCA concrete. The RCA specimens were then placed in the same previous conditions and the “secondary” ASR-induced development monitored over time. Results show that the overall damage in ASR-affected RCA concrete is quite different from affected conventional concrete, especially with regards to the severely damaged RCA particles, where ASR is induced by a reactive coarse aggregate, as the RCA particle itself may present several levels of damage simultaneously caused by past/ongoing ASR and newly formed ASR. Moreover, the influence of the original damage extent in such RCA concrete was captured by the slightly damaged RCA mixture eventually reaching the same damage level as the severely damaged mixture. Furthermore, the original extent of deterioration influence the “secondary” induced expansion and damage of RCA concrete since the higher the original damage level, the higher the cracks numbers and lengths observed in the RCA concrete for the same expansion level whereas wider cracks are generated by RCA having previously been subjected to slight damage thus indicating the difference in the distress mechanism as a function of original extent of damage. In addition, it has been found that distress on RCA containing a reactive sand generates and propagates from the residual mortar (RM) into the new mortar (NM) as opposed to RCA containing a reactive coarse aggregate, being generated and propagated from the original coarse aggregate (i.e. original virgin aggregate – OVA) into the NM. Likewise, RCA containing a reactive sand caused longer and higher number of cracks for the same “secondary” induced expansion than the RCA made of reactive coarse aggregate. Finally, novel qualitative and descriptive models are proposed in this research to explain ASR-induced distress generation and propagation on RCA mixtures made of reactive fine and coarse aggregates.

Afin de répondre aux questions des propriétaires de structures atteintes de réaction alcali-silice (RAS), ce travail se concentre sur une partie d'une méthodologie globale, proposée initialement par le LMDC et EDF, et dont le but est l'étude du comportement mécanique des constructions endommagées par la RAS. Pour atteindre cet objectif, l'avancement chimique de la RAS des granulats récupérés dans les structures affectées doit être évalué. Ainsi, ce travail est consacré à la quantification de la silice potentiellement réactive des granulats, par l'utilisation de deux approches : une approche indirecte par un test d'expansion et une approche directe par des méthodes chimiques. La présentation du manuscrit s'articule autour des points suivants :• Un test d'expansion pertinent et rapide sur mortiers pour relier la quantité de silice réactive à l'expansion mesurée. Les conditions expérimentales suivantes ont été choisies pour tester différentes tailles et natures de granulats, ainsi que différentes tailles d'éprouvettes : solution de NaOH à 1 mol/l et température de conservation de 60°C.• Une méthode chimique rapide de dissolution sélective pour mesurer directement la quantité de silice réactive disponible pour la RAS. La méthode HF / HF+HCl a été trouvé comme étant la plus efficace.• Un modèle chemo-mécanique pour analyser les effets de la taille des granulats et des éprouvettes, et évaluer l'avancement chimique de la réaction.Finalement, une méthodologie est proposée pour calculer la constante cinétique de la réaction dans le cadre de la requalification des structures atteintes de RAS. / In order to answer the questions of the ASR-affected structures owners, this work focused on a part of a global methodology, which is proposed originally by the LMDC and EDF, aiming to reassess the mechanical behavior of ASR-damaged constructions. To achieve this purpose, the chemical advancement of ASR in the aggregates recovered from the structure should be evaluated. Thus, this work focuses on the assessment of the potentially reactive silica content with two main methods: indirectly by expansion test and directly by chemical methods. The presentation of this manuscript is around the following points: • A relevant and rapid expansion test on mortars to link the reactive silica content to measured expansion. The experimental condition: 1 mol/l NaOH solution conserved at 60°C is chosen to test different aggregate sizes, specimen sizes and natures of aggregate. • A fast chemical method of selective dissolution to measure directly the silica available for ASR. Acid/basic methods are tested and compared; HF / HF+HCl method is found to be the most effective. • A chemo-mechanical model to analyze the effect of aggregate size and specimen size, and evaluate the chemical advancement of ASR. Finally, a methodology is proposed to calculate the kinetics constant in the framework of structural requalification. Key words: alkali-silica reaction (ASR), chemical advancement, reactive silica, expansion test, chemical test, chemo-mechanical model, kinetic constant, selective dissolution

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Natural rice husk ash (RHA) used in concrete contributes to civil construction sustainability. In fact, RHA is considered a residual pollutant and then it is necessary to destine this material correctly. However, it is necessary to investigate the consequences of replacing part of cement by natural RHA to produce concrete for structural purposes. In this context, the aim of this study was to evaluate the concrete durability produced with 15 % of blinder partial replacement by natural RHA in the expansion due to alkali-silica reaction (ASR) and penetration of chloride ion, as well as to suggest preventive measures with the use of mineral additions. In the present study, natural RHA was used as partially replacement of Portland cement. This natural RHA has been obtained without temperature control burning and placed directly into the mixer to suffer self-grinding with aggregates. We investigated the RAS neutralization of natural RHA by the use of cement with mineral additions (CPIIZ, CPIII e CPIV), as well as, we performed additional replacements of part from CPIIZ cement by fly ash (10, 15, 20, 30 and 40 %). We employed accelerated expansion method at 80°C in mortar bars followed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and long term at 38 °C and accelerated at 60 °C methods in concrete prisms. To investigate concrete resistance in the chloride ion penetration, we used chloride ions penetration method by immersion in saline solution (CPT) of concrete produced with natural RHA and CPIIZ cement added of fly ash (0, 12.75 or 17 %) and water-binder ratios of 0.45, 0.55 and 0.65 were adopted. Analyses of results were based in slope (K ) obtained from the average depths of penetration. In this study, we verified that in mortar bars assay the natural RHA generated expansion above of results allowed by norm in mixtures with standard cement, while CPIIZ cement with addition from 20 % of fly ash showed to mitigate the ASR. These results demonstrated that effect of mitigation of RAS proportionally increased with fly ash addition. Moreover, CPIV cement demonstrated excellence in mitigate the expansive reaction. The SEM analysis identified the characteristic products of ASR in the samples containing natural RHA. XRD analysis showed that the samples of mixtures with higher content of mineral addition showed peaks of calcium hydroxide (CH) with less intensity and mixtures with natural RHA presented greater calcium carbonate content. In relation to concrete prisms molded at 60°C, results showed an increase in expansion for mixture of CPIIZ with natural RHA, but these results remained below of maximum expansion predicted by test. Mixtures of CPII-Z with natural RHA added of 10 and 15% fly ash demonstrated better efficiency in expansion mitigation. In relation to concrete prisms molded at 38°C, the results are not conclusive to 12 months, but mixtures that presented a great expansion were of CPII-Z with natural RHA and 15% fly ash, the CPII-Z with RHA natural and CPII-Z with natural RHA and 10% fly ash, respectively. However, all mixtures had expansion below the maximum limit suggested by the Brazilian standard at 24 months. Through of results CPT, we can conclude that mineral additions provided improvements to the concrete with higher ages due to pozzolanic effect. Moreover, the best results obtained were in trace with lowest water-binder ratios, probably due to increased consumption of cement, which increases the CH amount to interact with the RHA and the fly ash. Therefore, mixtures of Portland cement with fly ash and natural RHA meet the durability of concrete, and also the use of natural RHA would be an important contribution to sustainability and preservation of environment by civil construction. / O emprego de cinza de casca de arroz (CCA) natural no concreto visa contribuir para a sustentabilidade da construção civil, destinando de maneira adequada, esse material que antes seria considerado um resíduo poluente. Porém, é necessária a investigação das consequências em substituir parte do cimento por CCA natural para produzir concreto com finalidade estrutural. Neste sentido, o objetivo deste trabalho foi avaliar a durabilidade de concretos produzidos com teor de 15 % de substituição parcial do aglomerante por CCA natural, frente à expansão devido à reação álcali-sílica (RAS) e à penetração de íons cloretos, assim como, sugerir medidas preventivas através do uso de adições minerais. No presente estudo, a CCA natural foi utilizada em substituição parcial ao cimento Portland no estado em que se encontra ao sair dos fornos de queima (sem controle de temperatura), diretamente na betoneira para sofrer auto-moagem com os agregados. Foi investigada a neutralização das RAS da CCA natural pelo emprego de cimentos com adições minerais (CPIIZ, CPIII e CPIV), assim como foram realizadas as substituições adicionais de parte do cimento CPIIZ por cinza volante (10, 15, 20, 30 e 40 %). Na investigação da RAS foram empregados os métodos de expansão acelerado a 80 °C em barras de argamassa acompanhado pela microscopia eletrônica de varredura (MEV) e difração de raios-X (DRX), e os métodos de longa duração a 38 °C e acelerado a 60 °C em prismas de concreto. Na investigação da resistência a penetração de íons cloretos foi empregado o método de penetração de íons cloretos por imersão em solução salina (EPCI) dos concretos produzidos com CCA natural e cimento CPIIZ adicionados de cinza volante (0; 12,75 ou 17 %) e nas relações água/aglomerante(a/ag) de 0,45; 0,55 e 0,65. A análise dos resultados do EPCI foi realizada com base no coeficiente angular da equação da reta (K ) obtido a partir das profundidades médias de penetração dos períodos investigados. Neste trabalho verificou-se que, no ensaio em barras de argamassa a CCA natural gerou expansão acima do permitido por norma nas misturas com cimento padrão, enquanto o cimento CPIIZ com adição a partir de 20 % de cinza volante se mostrou mitigador da RAS. Através desses resultados pode-se verificar que o efeito mitigador da RAS aumentou proporcionalmente com a adição de cinza volante. Além disso, o cimento CPIV mostrou excelência em mitigar a reação expansiva. A análise de MEV identificou os produtos característicos da RAS nas amostras contendo CCA natural e a DRX verificou que as amostras retiradas das misturas com maior teor de adição mineral apresentaram picos de hidróxido de cálcio (CH) com menor intensidade e ainda, que as misturas com CCA natural apresentaram maior quantidade de carbonato de cálcio. Em relação aos prismas de concreto moldados a 60 °C, os resultados mostraram maior expansão na mistura de CPIIZ com CCA natural, mas ela se manteve abaixo do limite máximo de expansão preconizado pelo ensaio. As misturas de CPII-Z com CCA natural adicionadas de 10 e 15 % de cinza volante mostraram melhor eficiência em mitigar a expansão. Em relação aos prismas de concreto moldados a 38 °C os resultados ainda não são conclusivos aos 12 meses, porém as misturas que apresentaram maior expansão em 12 meses foram as de CPII-Z com CCA natural e 15 % de cinza volante, de CPII-Z com CCA natural e CPII-Z com CCA natural e 10 % de cinza volante, respectivamente, entretanto, todas abaixo do limite máximo de expansão aos 24 meses, preconizado pela norma brasileira. Através das análises dos resultados do EPCI concluiu-se que as adições minerais proporcionaram melhorias ao concreto com maiores idades devido ao efeito pozolânico. Além disso, os melhores resultados obtidos foram nos traços com menor relação a/ag, provavelmente devido ao maior consumo de cimento que aumenta a quantidade de CH para interagir com a CCA e a cinza volante. Portanto, as misturas de cimento Portland com CCA natural e cinza volante atendem aos parâmetros de durabilidade do concreto, e com isso o uso da CCA natural seria um importante contribuinte na sustentabilidade e preservação do meio ambiente pela construção civil.

This study evaluates question of alkali–silica reaction (ASR) in hybrid system, which was designed in the bachelor's thesis, to meet the requirements of EN 197-1 and classified to the Blastfurnace CEM III/C cements. The durability of this system is a great unknown. For this reason, the same methods (ASTM C1260, ASTM C289 and ASTM C856) were used to observer the ASR effects as the ones used to observer the Portland cement based concrete. Supplementary methods include determination of compressive strengths according to EN 196-2 and scanning electron microscopy to observe the microstructure. Hybrid system results were compared to two different types of cements, CEM I and CEM III/B. From the results of the ASR evaluation assays, it was found that the hybrid system (CEM III/C-HB) and CEM III/B showed the lowest tendency to ASR. The results of the supplementary methods showed that CEM III/C-HB compressive strength increases after 14 days within NaOH by 43 % in comparison to 28 days strength. Based on those results, it is sure that the CEM III/C-HB shows little susceptibility to ASR.