In recent years, the use of self-compacting concrete (SCC) has been increasing. Although methods for designing the mixture proportions usually derive from experience with conventional concretes, some specific procedures still are not universally accepted. The design and characterization of SCC influences not only the mix components (paste volume and nature, binder amount and type, granular skeleton, etc.) but also the testing methods used to validate the self-compactability (usually in terms of fluidity, viscosity and resistance to segregation). This paper studies the influence on SCC mechanical properties based on the consideration of two types of granular skeleton, discontinuous and continuous, for different strength levels (35 and 60 MPa). For the both strength levels studied, the mix with continuous granular skeleton exhibited slightly higher segregation resistance and mechanical properties than did mixes with discontinuous granular skeleton. AbstractIn recent years, the use of self-compacting concrete (SCC) has been increasing. Although methods for designing the mixture proportions usually derive from experience with conventional concretes, some specific procedures still are not universally accepted. The design and characterization of SCC influences not only the mix components (paste volume and nature, binder amount and type, granular skeleton, etc.) but also the testing methods used to validate the self-compactability (usually in terms of fluidity, viscosity and resistance to segregation). This paper studies the influence on SCC mechanical properties based on the consideration of two types of granular skeleton, discontinuous and continuous, for different strength levels (35 and 60 MPa). For the both strength levels studied, the mix with continuous granular skeleton exhibited slightly higher segregation resistance and mechanical properties than did mixes with discontinuous granular skeleton.Keywords: self-compacting concrete, granular skeleton distribution, workability, compressive strength, modulus of elasticity, tensile strength, bond strength 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Experimental study about the effects of granular skeleton distribution on the mechanical properties of self-compacting concrete (SCC) Cover Letter AbstractIn recent years, the use of self-compacting concrete (SCC) has been increasing. Although methods for designing the mixture proportions usually derive from experience with conventional concretes, some specific procedures still are not universally accepted. The design and characterization of SCC influences not only the mix components (paste volume and nature, binder amount and type, granular skeleton, etc.) but also the testing methods used to validate the self-compactability (usually in terms of fluidity, viscosity and resistance to segregation). This paper ...

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The new generation of innovative projects has led to the use of greater amounts of reinforcement and the development of concrete with specific characteristics. It is necessary to use a material that ensures the uniformity of the cross section, as well as the adherence of the existing reinforcement, and due to this, the self-consolidating concrete becomes an technique alternative has great potential to achieve these properties. The aim of this paper is to analyze the bond behavior of self-consolidating concrete that was obtained by means of the Beam Test performed within a large experimental campaign of characterization. Four types of SCC were studied with two strength levels (40 MPa and 60MPa) and two different types of granular skeletons, using two specimens at each age (3, 7, and 28 days). All specimens were tested with a corrugated steel bar 10 mm in diameter. The results show that the adhesion tension independently of resistance presents a rapidly evolving at 7 days reached 95% of the total adhesion by 28 days. Resumen La necesidad de proyectos innovadores ha conducido al empleo de mayores cuantías de armadura y al desarrollo de concretos con características especiales. Para ello, se hace necesario el empleo de un material que garantice la homogeneidad de la sección transversal, así como, la adherencia de la armadura existente; en este sentido, el concreto autocompactante se torna una alternativa técnica con gran potencial para atender esas propiedades. El objetivo de este trabajo es analizar los resultados de la resistencia de adherencia del concreto autocompactante obtenidos en una amplia campaña experimental. Se ha trabajado con dos niveles de resistencia a la compresión (40 y 60 MPa) y con dos esqueletos granulares distintos. Se ha empleado el ensayo de la viga (UNE 36740: 1998) para medir la tensión de adherencia a 3 edades diferentes (3, 7 y 28 días). Todas las probetas fueron ensayadas con una barra corrugada de acero de 10 mm de diámetro. Los resultados muestran que la tensión de adherencia independientemente de la resistencia, presenta una evolución rápida, alcanzando a los 7 días un 95% del total de la adherencia a los 28 días.

El trabajo de los profesores en la universidad se evalúa en ámbitos muy diversos: docencia, investigación, com promiso con la universidad, etc. En la mayoría de las ocasiones esta evaluación se hace de forma segregada, a pesar de formar parte integrada de la actividad del profesor con evidentes interacciones entre sus partes. Por ello, es muy útil disponer de una metodología de evaluación que considere los múltiples criterios de forma conjunta. El objetivo de este artículo es aplicar la metodología del modelo integrado de valor para evaluaciones sostenibles (MIVES) para la selección de candidatos en una habilitación a cátedra. Mediante MIVES se pretende tener en cuenta de forma integrada los diferentes aspectos que conforman la actividad ordinaria de un profesor, tanto en el entorno interno de la propia universidad, como en el externo, ya sea profesional, académico o social. El sistema MIVES plantea una estructura integral para la evaluación, utiliza funciones de valor para la ho mogeneización de las unidades de cada uno de los criterios definidos y aplica un proceso de análisis jerárquico de comparación por pares para la obtención de los pesos relativos. MIVES fue aplicado en una primera habilitación a cátedra con unas deducciones concordantes con los resultados de dichas pruebas. En este artículo se expone esta metodología aplicada en un segundo proceso de habilitación cuyo objetivo era verificar si el modelo funcionaba en otra área de conocimiento. Los resultados obtenidos volvieron a ser consisten tes con los resultados reales de dichas pruebas.