Centro de Investigación y Desarrollo de las Estructuras y los Materiales (CIDEM)
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Examinando Centro de Investigación y Desarrollo de las Estructuras y los Materiales (CIDEM) por Autor "Martirena Hernández, José Fernando"
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Ítem Acceso Abierto Considerations for the energy balance and preliminary design of an experimental LC3 Cement Pilot Plant(2019-06-15) Machado López, Iván; Herrera Moya, Idalberto; Martirena Hernández, José Fernando; Universidad Central "Marta Abreu" de Las Villas. Facultad de Construcciones. Centro de Investigación y Desarrollo de las Estructuras y los Materiales (CIDEM)Associated with cement manufacturing processes, large amounts of carbon dioxide (CO2) are released into the atmosphere, it is estimated that between 0.65 - 0.90 tons of CO2 are emitted per ton of cement manufactured. By 2050, the demand for this binder is expected to exceed 5,000 million tons, which would contribute to an increase of more than 3% of emissions. However, the emissions can be reduced by using supplementary cementitious materials (SCM), in this sense the calcined clays have a great potential for the reduction of emissions in the manufacture of cement, has been studied in recent years’ low carbon cement or LC3, developed by a joint team of the University of Lausanne and the Central University of Las Villas. The main results are the expansion of production by achieving clinker substitutions of up to 50%. In this sense, the Center for Research and Development of Technologies and Materials (CIDEM) in conjunction with the company IPIAC-NERY has committed to the development of a small pilot plant that makes the manufacture of limited quantities of LC3, which allows the study of the process by interacting different sources of raw materials. In this paper some calculations were for designing a pilot plant, taking into account the balance of mass and energy necessary for its proper functioning, which in turn allows to specify the technology for the scaling of the production in any new industrial plant or adaptation of capacities installed.Ítem Acceso Abierto Evaluation of different treatment techniques in recycled aggregates for use in concrete production(2019-06) Limonte Morales, Giselle Bárbara; Martirena Hernández, José Fernando; Universidad Central "Marta Abreu" de Las Villas. Facultad de Construcciones. Centro de Investigación y Desarrollo de las Estructuras y los Materiales (CIDEM)The results of 5 months of research in the topic Concrete produced with 100% recycled aggregates are presented. We worked with a mixed type recycled material from Madrid, Spain and the tests were carried out in the laboratory (OBP) of the University of Applied Sciences of Karlsruhe, Germany. The recycled material was characterized and separated into three fractions for use as aggregates in the production of concretes (i) fine fraction 0-4 mm (ii) intermediate fraction 4-9 mm (iii) coarse fraction of 9-16 mm. To improve the properties of the recycled aggregates, different treatments were used for each of the fractions (i) accelerated carbonation of the fine fraction, (ii) encapsulation of the intermediate fraction with steam curing, (iii) use of MSC, in this case an active mineral addition of calcined clay-limestone base, denominated by its acronym in English LC2. Established as state parameters for accelerated carbonation of the fine fraction Relative Humidity = 75%, CO2 concentration = 20% and residence time of 24 h, which resulted in an increase of 0.7% in the formation of Calcite with respect to the fine fraction without carbonation, the absorption of water decreased by 0.63% and the resistance in mortars after 28 days of curing exceeded by 0.89% the strength of the fraction without carbonation, 28 Mpa and 31 , 43 Mpa respectively. For the steam curing of the encapsulated fraction, it was worked under conditions of temperature lower than 60o and a residence time of 30 min, obtaining a decrease of 0.75% in the absorption of water with respect to the material without encapsulating. In the concretes produced with the treated aggregates, the best performance series was that which uses a combination of fine carbonated aggregate, encapsulated intermediate aggregate with steam curing and Portland cement 32.5 Mpa.Ítem Acceso Abierto Solución Sostenible con la introducción del aditivo de origen biológico como reductor de la retracción en hormigones fluidos de 35MPa(2017-07) Díaz García, María Betania; Díaz Cárdenas, Yosvany; Martirena Hernández, José Fernando; Ramos Méndez, Robelio; Universidad Central "Marta Abreu" de Las Villas. Facultad de Construcciones. Centro de Investigación y Desarrollo de las Estructuras y los Materiales (CIDEM)Los altos costos y la monopolización del mercado de aditivos químicos incentivan a países en vías de desarrollo, incluyendo a Cuba a buscar nuevas alternativas que incluyan un desarrollo sostenible y próspero. Una de las alternativas que se están investigando en este momento para sustituir los aditivos químicos, se basa en el estudio de un aditivo plastificante de origen biológico, denominado por sus creadores como CBQ-VTC (Centro de Bioactivos Químicos Viscosificante Tensoactivo Controlador). En el presente trabajo se evalúa el bio-producto CBQ-VTC y su efecto sobre la retracción en hormigones fluidos de 35 MPa, para ello se varía los porcientos del bio-producto en 2%, 3% y 4%, y el aditivo químico SRC-20 en un 0.8% del peso del cemento. El trabajo se realiza en dos etapas: en la primera se procede al estudio de las propiedades reológicas como son asentamiento por el cono de Abrams y tiempo de fraguado; en la segunda se realizan los ensayos en estado endurecido como resistencia a compresión, retracción según la ASTM-C- 157 y permeabilidad al aire. Los resultados de estos ensayos aportan al avance y afianzamiento del uso de la tecnología de aditivos biológicos y forman parte del desarrollo eminente desde el punto de vista ambiental del bio-producto CBQ-VTC como un aditivo reductor de la retracción.Ítem Acceso Abierto Studies carried out on concretes produced with LC3 according to Cuban standard NC 120: 2014(2019-09) Valdés Alemán, Eilys; Díaz Cárdenas, Yosvany; Martirena Hernández, José Fernando; Universidad Central "Marta Abreu" de Las Villas. Facultad de Construcciones. Centro de Investigación y Desarrollo de las Estructuras y los Materiales (CIDEM)As part of the development strategy of the LC3 in Cuba, a procedure is developed for the preparation of concretes with different doses (H1, H2, H3, H4) according to the levels of atmospheric aggressiveness established in NC 120: 2014 "Hydraulic concrete - Specifications Concretes will be made that respond to three designs of mixtures where parameters such as cement content and water / cement ratio vary according to what is established in the aforementioned standard. The rheological and physico-mechanical behavior of concrete will be evaluated in a fresh and hardened state, for which the following tests will be carried out: Determination of the settlement by the cone of Abrams and the strength of the hardened concrete at 3, 7 and 28 days of curing. The concretes will be made with low carbon cement (LC3) up to 50% replacement of the clinker, calcined clays and limestone, and the patterns, made with Portland cement 35 (P35). Curing influence for the H1 series will be evaluated in both standard and LC3 manufactured concretes.