Search

Currently, one of the most important trends in concrete technology is the use of inert fine particles (fillers) to decrease cement content, increase packing in the paste and increase flowability, with gains in technological, environmental and cost aspects. The advance in dispersion technology (using superplasticisers) is one of the technical issues that allows pastes to be mixed without the expected increase of water content – which decreases compressive strength – caused by the filler's high surface area. However, the use of no more than the optimal dispersant (superplasticiser) content (lowest content that provides the lowest viscosity) is crucial owing to cost constraints. This paper evaluates the possibility of predicting optimal dispersant content in cement–limestone filler systems from the optimal dispersant content previously measured in the pure raw materials. Owing to the need for only a few sets of tests, this can optimise the design timing and accuracy of efficient pastes for lower binder concretes.

The use of pre-hydrated cement in formulation of mortar and concrete is common because there is not always effective control on the cement production, grinding, transportation and subsequent storage. This paper presents a case study on the optimization of admixture for use with prehydrated cement by assessing changes in the rheological properties of Portland cement artificially pre-hydrated. The cement was artificially pre-hydrated by exposure to relative humidity (RHs) of 90%, in an environment of NH4Cl saturated solution. Additionally, the cement pastes were evaluated with and without superplasticizer. Stepped flow test using a parallel-plate geometry was the method choose to evaluate the rheological behavior, apparent viscosity, yield stress and hysteresis area of each paste at the early age. Oscillatory rheometry was conducted to evaluate the storage modulus (G’), comparing the consolidation with the hydration kinetics obtained by calorimetric evaluation of the same suspensions. Initial rheometer results indicate that the pre-hydrated sample presents lower level of shear stress than the reference sample, because of the higher reactivity of the non-pre-hydrated sample. Resumo A utilização de cimento pré-hidratado na formulação de argamassas e concretos é comum, pois nem sempre há um controle efetivo na produção do cimento, moagem, transporte e posterior armazenamento. Este trabalho apresenta um estudo de caso sobre a otimização de aditivo para uso com cimento pré-hidratado, avaliando as mudanças nas propriedades reológicas do cimento Portland pré-hidratado artificialmente. O cimento foi pré-hidratado artificialmente por exposição à umidade relativa (URs) de 90%, em ambiente de solução saturada de NH4Cl. Adicionalmente, as pastas de cimento foram avaliadas com e sem superplastificante. O teste de fluxo escalonado usando uma geometria de placas paralelas foi o método escolhido para avaliar o comportamento reológico, viscosidade aparente, tensão de escoamento e área de histerese de cada pasta em idade precoce. A reometria oscilatória foi realizada para avaliar o módulo de armazenamento (G'), comparando a consolidação com a cinética de hidratação obtida pela avaliação calorimétrica das mesmas suspensões. Os resultados iniciais do reômetro indicam que a amostra pré-hidratada apresenta menor nível de tensão de cisalhamento do que a amostra de referência, devido à maior reatividade da amostra não pré-hidratada.

The production of Portland cement (PC) clinker is responsible for about 6·5% of total carbon dioxide (CO2) emissions worldwide. Therefore, recent studies have focused on alternatives to decrease PC content and thus reduce the carbon footprint of concrete construction. Although guidelines suggest a minimum cement content of approximately 250–300 kg/m3 depending on the type of the structure or structural member, there is currently a lack of information on the impact of the amount of cement on the overall behaviour of concrete. This work evaluates the influence of PC (ASTM C150 Type III) content on the fresh (i.e. rheological behaviour) and hardened (i.e. compressive strength, dynamic and static modulus of elasticity, porosity and permeability) properties of concrete mixtures produced with low to moderate (54, 159 and 260 kg/m3) PC amounts. Results show that it is possible to produce eco-efficient concrete without compromising the fresh and hardened states of the material. However, the durability and long-term properties of low cement content systems should be further appraised.

In the industrial processing of vermiculite, a fine residue is generated for which an application that allows its large-scale use has not been developed yet. The association with Portland cement in mortar and concrete compositions may be an alternative, because of the chemical composition of vermiculite with high amount of aluminum, silicon and magnesium, similar to other additions used in substitution to Portland cement. However, due to high specific surface area of vermiculite compared to cement, its use may affect the rheological properties and the water demand, thus limiting its application. This work was carried out with the objective of evaluating the impact on rheological properties of cement pastes prepared with partial replacement of Portland cement by vermiculite fine residues, both as obtained and calcined. The vermiculite fine residue contents were varied from 5 to 20%, and the compositions were submitted to a stepped flow test, with changes in the shear rate. There were almost no changes in rheological properties in suspensions with 5% of cement substitution by vermiculite fines. However, when >10% of vermiculite was used, considerable changes in flow could be observed as a function of both the residue content and the nature of the vermiculite (as-obtained or calcined). The YODEL and Interference models, based on the physical characteristics of the particles, were applied to estimate the yield stress (YODEL) and viscosity (Interference), and the calculation results indicated that there was a good correlation with the experimental data, indicating than the rheological properties of the pastes were directly related to physical properties of the particles.

The effect of time on soil properties, noticeable in many earthworks, is recognized by geotechnicians. For example, secondary compression and aging pre-consolidation are considered in geotechnical design, and strain rate is standardized in geotechnical laboratory and field tests. Elastic-plastic models, from rigid-perfect plastic to Modified Cam Clay, which do not consider the effects of time, solve most geotechnical problems. However, solutions for prolonged settlements, landslides, debris flow and mudflow could profit from a deeper understanding of rheological models. In fact, rheological concepts, despite not always clearly stated, have been used to address some of these problems, and may also be important for using new materials in geotechnical practice (tailings, sludge, soil-polymer mixtures and other materials with water content higher than the liquid limit). This paper introduces basic concepts of rheology for geotechnicians, specially highlighting viscoelasticity under simple shear stress, which explains with reasonable accuracy well known phenomena dependent on time in soils. The objective is to bring geotechnicians to rheology and show another important tool to access geotechnical problems. On the other hand, a brief explanation of geotechnical tests is presented for rheologists not acquainted with geotechnical engineering. Geotechnical tests procedures are discussed in the light of rheology concepts, terminology is clarified, examples of application of rheology in geotechnics are presented, and determination of soil rheological parameters by traditional geotechnical tests as well as by tests on concrete is commented.

The modernization of building systems is increasingly demanding products that improve efficiency during their processing. The development of self-leveling mortars for the regularization of flooring is a consequence of this evolution. The high contents of binder and water to obtain self-flowing property, plus the application of thin layers over large areas, make this type of mortar susceptible to high shrinkage levels. Thus, the ternary system Portland cement-calcium aluminate cement-calcium sulfate (OPC-CAC-CaSO4) is a viable solution for shrinkage compensation. The expansion mechanism based on ettringite formation aims to prevent the mortar from cracking. Considering its complexity and that international literature is still limited (while Brazilian is null), this article presents a literature review that covers diverse aspects related to the application of the system OPC-CAC-CaSO4. The influence of raw materials and mix proportions on rheological behavior, reaction kinetics, development of strength, and length change are discussed.

Adding TiO2 tocoating mortars is carried out to promote self-cleaning through photocatalytic activity. However, this addition influences the workability of the mortar and, consequently, the application stage as the TiO2 used can present a large number of fine particles and a high surface area, increasing the demand for mixing water, requiring consistency adjustments before coating. In this work, three mortars (two with the addition of different types of TiO2 and one reference) were developed on a laboratory scale to maintain similar workability, using the flow table test. The amount of kneading water was changed to maintain a spread of 220 ± 10 mm and the content of air-entrained was kept constant, around 25%. The mortars were evaluated using the squeeze flow method. Then, a blind test was performed to assess the mason sensitivity during handling and application of the coating, and all mortars were considered similar. However, the yield of the compositions with TiO2 addition was lower compared to the reference composition, making it possible to explain the results based on the physical parameters of the formulations and with a more in-depth analysis of the rheological indices obtained by the squeeze flow test.

Resumo Este trabalho foi realizado com o objetivo de avaliar o impacto do tipo de substrato e do tratamento da superfície na resistência de aderência e na permeabilidade de argamassa de revestimento. Para tanto, uma mesma argamassa foi aplicada sobre blocos cerâmico e de concreto, e substrato-padrão de concreto, nos quais foram realizados tratamentos superficiais com hidrofugante e silicone para alterar os níveis de absorção de água sem mudar a rugosidade superficial. Todas as condições de mistura, aplicação e cura foram mantidas constantes e os resultados indicaram que há considerável diferença no espalhamento e no tempo em aberto das argamassas em função do tipo de substrato ou tratamento superficial; não houve diferença estatística nos resultados de resistência de aderência ou permeabilidade das argamassas aplicadas sobre os blocos cerâmico e de concreto, independente do tratamento da superfície, porém os valores foram menores do que para as argamassas aplicadas sobre o substrato-padrão de concreto; e apesar de o coeficiente de absorção de água dos substratos influenciar diretamente os parâmetros avaliados, para cada tipo de substrato foi observada uma tendência, indicando que a absorção é importante, porém não é a variável de maior interferência na aderência argamassa-substrato. Abstract The main purpose of this study was to evaluate the impact of the substrate type and water absorption on the properties of rendering mortars. A mortar was applied on ceramic and concrete blocks and on standard concrete substrate, which received superficial treatments with water repellent and silicon. This strategy was used to alter the water absorption without changing the roughness. The mixture, application, and cure of the mortars were kept constant, and the results indicated that there are considerable differences in the spreading and open-time of mortars depending on the surface treatment and substrate type; there were no statistical differences in the adhesion or permeability of mortars applied on the ceramic and concrete blocks, regardless of surface treatment, but the values were much lower than those observed on the standard concrete substrate; and even with a direct influence of the coefficient of water absorption on adhesion and permeability, a different tendency was observed for each kind of substrate, indicating that, while absorption is important, it is not the main variable influencing the performance of coatings.

The paper discusses the potential of fillers in CO2 mitigation in the cement industry. A historical overview of the use of fillers is presented as well as the limits of filler use given in cement standards. Globally, limestone filler currently represents only 7% of average worldwide cement composition. The limits of the current route to adding filler in cement by means of intergrinding are discussed. An innovative technology, that compensates binder dilution by a reduction of the water required for good rheological behavior, is presented; this allows clinker replacement rates of up to 70%. The theory that enables the design of such multimodal particle size distributions with high particle packing and low-water demand is presented, and examples of its application in concrete production are given. The efficiency in terms of CO2 mitigation is demonstrated by comparing concrete formulations designed with this innovative approach with a global benchmark of current technology. New filler minerals, as well as the effects of high-filler content on production processes and on durability are also discussed.

The squeeze flow test provides relevant information about the macroscopic rheological behavior of mortars. Nevertheless, the identification and characterization of micro and meso physical phenomena is necessary for a more thorough analysis. This work presents an experimental methodology that combines the squeeze flow test with a pressure mapping system for the rheological evaluation of cement-based mortars. Two compositions were analyzed, with and without viscosity modifying cellulose ether based admixture, and the liquid phase migration was quantified to support the interpretation of the results. The developed pressure mapped squeeze flow (PMSF) method allowed for reliable measurement of the evolution of the pressure distribution on the whole area of the squeezed sample, and the results were compared with theoretical models for different flow types and rheological behaviors. The presence of the cellulose ether admixture resulted in more homogeneous flows, which enabled bigger displacements and generated less fluctuations in the pressure distributions.

Resumo A utilização de incorporadores de ar em argamassas de revestimento é comum no setor construtivo e estudada há muitos anos, seja na academia ou em centros privados de pesquisa. Por isso, uma gama muito ampla de informações obtidas com os inúmeros estudos são reportadas em literatura, na maioria dos casos ilustrando os efeitos da incorporação de ar, trabalhabilidade, espalhamento, módulo de elasticidade, aumento da permeabilidade ao ar, etc. No entanto, poucas informações são obtidas com relação às causas que resultam em tais efeitos, o que pode ser considerada a fonte das incertezas e empirismo durante o processo de desenvolvimento de tais composições cimentícias. Assim, neste trabalho é apresentada uma revisão sobre as variáveis que influenciam na incorporação de ar nos sistemas cimentícios, que aponta para o impacto da utilização do aditivo na água em presença de cimento (pasta) e na argamassa como um todo.

Substituting cement with fillers is crucial to formulate cost-effective cementitious materials with low CO2 emissions. However, despite limestone, there is a lack of knowledge of fillers from other mineralogical sources for use in cementitious pastes. This study investigates the effects of characteristics of fillers from 6 mineralogical sources on the reactivity and compressive strength of the cementitious pastes, which could allow increasing industrial possibilities. The filler density and the paste total bound water content allowed to determine the paste porosity, which has a much better fit with the compressive strength than the water-binder ratio.

Due to environmental issues, the concrete chain seeks to reduce CO2 emissions. However, growing demand from developing countries causes the increase of CO2 emissions in production to exceed decreases generated by industrial actions, such as improving kilns and clinker replacement. New strategies are important. Changes in the concrete formulation, making it more efficient, can help if these changes produce concrete with the same performance and lower cement consumption. In this regard, the improvement of packing and dispersion of particles increases this efficiency. The better the packing, the lower the volume of voids between particles, thereby requiring lower fluid content (water) to permit flow. The dispersion of the particles also decreases the water content for the same fluidity. The less the water content, the smaller the water/cement (w/c) ratio, and the greater the resistance. Thus, both strategies increase the efficiency by uncoupling obtaining fluidity from the water content. This study investigated the influence of packing and dispersion on the efficiency of cement use in concrete. The increase of packing and the complete dispersion of fine particles has been shown to improve efficiency, as measured by the ratio between binder consumption and compressive strength (the performance parameter used in most practical applications). Resumo Devido a questões ambientais, a cadeia do concreto busca reduzir emissões de CO2. Porém, a demanda crescente de países em desenvolvimento faz com que o aumento da produção supere as diminuições geradas por ações industriais como melhoria de fornos e substituição de clínquer. Novas estratégias são fundamentais. Mudanças na formulação de concretos, tornando-a mais eficiente, podem ajudar caso produzam concretos de mesmo desempenho e menor consumo de cimento. Neste sentido, a melhoria do empacotamento e dispersão das partículas aumentam esta eficiência. Quanto melhor o empacotamento, menor o volume de vazios entre as partículas, demandando menor teor de fluido (água) para permitir fluidez. A dispersão das partículas também diminui o teor de água para a mesma fluidez. Quanto menos água, menor a relação a/c e maior a resistência. Assim, ambas as estratégias aumentam a eficiência ao desatrelar a obtenção de fluidez ao teor de água. Este trabalho estudou a influência do empacotamento e dispersão na eficiência do uso do cimento de concretos. Demonstrou-se que o aumento do empacotamento e a completa dispersão das partículas finas permitem atingir melhor eficiência - medida pela relação entre consumo de ligantes e resistência à compressão (parâmetro de desempenho utilizado na maior parte das aplicações práticas).

Squeeze flow rheological technique is based on the compression of a cylindrical sample between parallel plates and is used to determine the flow properties of food, pharmaceuticals, composites, suspensions, including cementitious materials. This work summarizes the main experimental developments on squeeze-flow for the evaluation of mortars that have been performed in Brazil for the last 15 years and supported the creation of the Brazilian standard test method applied to rendering and masonry mortars (ABNT NBR 15839:2010). The paper exemplifies possible test setups (configuration, geometry, velocity, roughness) for different types of mortars and situations, the use of porous substrate (ceramic or concrete blocks) as the bottom plate, and a method to measure phase separation induced by the. A complementary instrumentation (interfacial pressure mapping) for the assessment of pressure evolution during flow is also presented – forming the pressure mapped squeeze flow method (PMSF) – which allows for identification of transitions in flow type and localized pressure peaks resulting from microstructural changes like particle jamming. The technique was also employed to study and develop laboratory mixing methods for mortars, as the resulting flow curves are very sensitive to the material’s agglomeration state. Finally, rheological parameters of mortars by squeeze-flow and rotational rheometry were compared showing that yield stress have some degree of agreement, whereas viscosity values from these techniques are complex to be related.

The mixing procedure used to make paste, mortar or concrete has an important influence on the hydration kinetics and rheological properties of cementitious materials. In this study, different shear mixing procedures were studied to evaluate the effect on the kinetics of hydration for Portland cement paste by isothermal calorimetry over 72 h. The rheological properties of the same pastes in terms of yield stress (Pa) and apparent viscosity (Pa.s) were also studied with the same mixing procedures: manual, 2500 rpm and high shear mixing at 10000 rpm. To compare the heat flow over the time of each mixing procedure with the stiffening, an oscillatory rheometry evaluation with continuous flow was carried out. All the tests were carried out in triplicate and the variability was evaluated.

Particle Size Distribution (PSD) has impact on the workability of concretes because it affects the particle packing and particle mobility during flow. In continuous concrete production, keeping always the same PSD is not possible. So, it is important to understand how this variability affects concrete properties. The research described in this paper evaluated a more sustainable low-binder concrete, with focus on particle size variability of the aggregates. Applying particle packing and dispersion concepts, rheological control, use of limestone fillers and appropriate choice of material, a reference concrete with low binder consumption (3.7 kg/m3/MPa) was developed. On this reference concrete, PSD variations were applied: a coarser and a finer version for each aggregate was tested and two levels of fines content were also evaluated. Mixing behavior and rheological properties were determined by a concrete mixing rheometer (Pheso Poli-USP) with planetary configuration. An acceptance criterion was established based on mixing torque and all concrete outside the limits had their water content adjusted until they met the specifications. After that, mechanical strength was evaluated at 28 days of age. The obtained results indicate that PSD variations affected both the mixing and flow of concrete. Especially higher fines content and presence of a finer natural sand increased the torque levels during the mixing process and shear cycles and lead to higher mixing power demand. The water correction, adopted to overcome the rheological changes, affected hardened state properties (up to 10% on compressive strength). As these findings are specific to the analyzed concrete and considered PSD variations, this research aimed to explain more generally the influence of the several variables. The surface area of the granular material, solids concentrations and mean distance between the fine and coarse particles are some quantitative parameters useful for predicting rheological aspects of concrete compositions.

Mortars and concretes are subjected to diverse rheological situations during their processing and application. Their behavior can be predicted for most situations by rotational rheometry and/or squeeze flow. However, very high strain rates that occur during impact are very difficult to be properly simulated using these methods. Especially for rendering mortars, impact behavior (during manual or spray application) is important not only regarding productivity and rebound issues but also because the initial mortar-substrate contact extension strongly affects the interfacial bond strength, which is one of the renders most critical hardened properties. The present work introduces initial developments towards an impact rheometry technique intended primarily for cementitious and other suspensions used in construction. The technique is based on a pressure mapping system that measures area and force with a thin and flexible sensor at 100 Hz. Mortars were applied manually, by continuous spraying, and by free fall. Results showed that in manual application, pressures up to 50 kPa took place, whereas in the mechanical procedure the pressure values were considerably lower (>5 kPa) since the force is distributed in small portions of material by the spray. Some of these results can be useful to compare projection techniques and equipment, for the development of nozzles, and to set free fall drop heights to better simulate manual applications and even allow more realistic molding procedures for mortar-substrate tensile bond tests.

Concrete greenhouse gas emissions are mostly from cement. A relevant strategy for the concrete greenhouse gas emissions abatement is the increase of the efficiency in the use of its binder. For this, it is important to understand the packing and the mobility of the concrete particles and their effects on its rheological behavior in the fresh state and the mechanical properties in the hardened state. Currently, the mix design methods are empirical, as opposed to this experimental optimization, the computational optimization emerges, based on predictive models. Thus, the objective of the study is to use the physical model based on particle mobility to predict the rheological behavior of commercial concretes. The method consisted in the following steps: characterization of raw materials; eco-efficiency analysis of 60 formulations of a concrete plant using the binder intensity concept; and a parameter estimation for a descriptive model of slump in function of mobility variables. These concrete formulation binder intensities were between 7.5 and 10.5 kg/m3/MPa, in which the rise of specified fck and maximum aggregate size have a positive impact on this index, while the slump growth has a negative effect. For the base formulations, the mobility variable MPT (Maximum Paste Thickness) showed good correlations with the specified slump (R2 0.99), as well as the model presented a good adjustment to the data (R2 0.94). These results allow an improvement in the mix design methodology using computational optimization, which can lead to an increase on the eco-efficiency of the commercial concretes.

Resumo No processo de beneficiamento da vermiculita é gerado um resíduo fino para o qual atualmente ainda não foi desenvolvida uma aplicação que possibilite a utilização em larga escala. Uma alternativa que vem sendo estudada é a associação com cimento Portland em composições de argamassas e concretos, em função da composição química do resíduo: elevada quantidade de alumínio, silício e magnésio, que podem apresentar interações com o ligante. Como o objetivo deste trabalho foi avaliar unicamente o impacto do uso do resíduo nas propriedades no estado endurecido das argamassas cimentícias, as composições foram misturadas utilizando-se a mesma relação água/sólidos, independente das alterações na consistência. Os teores de substituição foram variados de 5 a 20% e as propriedades no estado endurecido foram avaliadas a partir de ensaios de Arquimedes, resistência à tração na compressão diametral, módulo de elasticidade dinâmico e permeabilidade ao ar. Os resultados indicaram que até o teor de 10% de substituição não houve alterações estatisticamente significativas nos produtos, independente do processo de calcinação. Abstract In the process to obtaining vermiculite a fine residue is generated, which does not yet have a large-scale application. An alternative that has been studied is the association with Portland cement in mortar and concrete formulations, due to the chemical composition of the residue: high amount of aluminium, silicon and magnesium which may have interactions with the binder. As the objective of this work was to evaluate the impact of the use of the residue on the cementitious compositions without altering the water-to-solid ratio, the compositions were mixed using the same amount of water, independently of the changes in the consistency of the mortars. Replacement levels were varied from 5 to 20% and Archimedes immersion, tensile strength in diametrical compression, dynamic modulus of elasticity and air permeability tests were used. The results indicated that up to the 10% substitution content there were no statistically significant changes in the products, independently of calcination process.

Resumo A aplicação de ladrilhos hidráulicos voltou a ser valorizada nos últimos anos em função de sua beleza e versatilidade. O ganho de resistência sem necessidade de queima é uma considerável vantagem, mas o tempo e o custo de produção e a manutenção em estoque são algumas desvantagexns observadas. Como são materiais que permanecem expostos durante o uso, devem ter propriedades como estabilidade de cor, resistência à abrasão e estanqueidade controladas. O objetivo deste trabalho foi avaliar o impacto do tipo e teor de pigmento (à base de óxido de ferro ou negro de fumo) no estado endurecido dos pisos. As misturas foram realizadas com diferentes teores de pigmento (0,05%, 0,30% e 0,60%) e os resultados avaliados em função da alteração da cor, absorção de água, resistência à abrasão/flexão, módulo elástico e permeabilidade indicaram que não houve um padrão com relação ao pigmento utilizado e cada propriedade foi alterada de forma distinta. Abstract The application of hydraulic tiles has been valued in recent years due to its beauty and versatility. The gain of resistance without the need for burning is a considerable advantage, but the time and cost of production and maintenance of the product conformed in stock are some disadvantages observed. As these materials must remain exposed during the use, they must have properties like color stability, abrasion and stain resistance controlled. The main goal of this study was to evaluate the effect of the type and content of pigment (based on iron oxide or carbon black) on the hardened state properties of these tiles. Mixtures were carried out using different pigment content (0.05%, 0.30% and 0.60%) and the results evaluated as a function of color change, water absorption, resistance to abrasion/flexural strength, elastic modulus and permeability indicated that there was no correlation between the kind or content of pigment and the properties evaluated.

Concrete, the major construction material used in the construction industry worldwide, presents a huge environmental impact producing about 7% of the global carbon dioxide. Given the concerns related to global warming, studies have been focusing on distinct approaches aiming to reduce the amount of Portland cement (PC), which is the least sustainable ingredient of the mixture, by adopting alternative mix-design strategies such as the use of particle packing models (PPMs). However, there is currently a lack of data on the efficiency of the use of continuous PPMs to reduce PC while maintaining or improving concrete fresh and/or hardened properties. This work aims to investigate the impact of current and modified versions of continuous PPMs on the fresh (rheological behaviour) and hardened (compressive strength, modulus of elasticity, porosity, and permeability) state of mixtures designed with low and moderate amounts of PC. Results demonstrate that eco-efficient concrete may be produced through current and modified continuous PPMs without compromising the fresh and hardened properties of the material. Nevertheless, further durability and long-term investigations must be performed on systems with reduced PC contents.

This study is part of a global project to find some large-scale application for red mud. A previous work confirmed that the use of RM as partial substitution for cement can affect its rheological properties; however, it is possible to produce cementitious materials without lose mechanical performances at harden state. The main goal of the work was to assess the impact of red mud (RM) as replacement of different Brazilian Portland cements by monitoring the formation of hydrated products over time, by thermogravimetry, X-ray diffraction and FTIR. Results show that the presence of RM increases the induction period, the gypsum and portlandite consumption as well as the amount of ettringite and monosulfoaluminate produced. The formation of sodium silicoaluminate hydrate (NASH) was also observed, regardless the kind of cement, as a result of the reaction with aluminates and silicates from the binder.