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In this paper, results about an experimental study performed on plaster compounds with the incorporation of rubber in the form of fibers from end of life tires are reported and analyzed. Test samples of plaster are prepared adding different volumetric fractions of rubber fibers that had been previously classified into two different sizes. The same consistency is fixed for every compound studied. Physical and mechanical properties are analyzed. Thermal behavior is also studied comparing thermal conductivity values and relating them with the bulk density of the resulting material. The results show an improvement in the thermal behavior proportional to the reduction of the density and the mechanical properties, as the proportion of rubber increases. It is also observed that there are no significant differences depending on the size of the fibers. These results confirm that the new material obtained is comparable to other materials of lightweight plaster with improved thermal properties and therefore with the same possibilities of use as these materials. The new material could be used for slabs and compression layers in building rehabilitation. Keywords: Plaster, rubber fibers, mechanical properties, thermal conductivity, acoustic insulation.

Resumen-En este trabajo se analizan los efectos de la incroporación de algunas de las fibras más utilizadas en el Mercado (basalto, vidrio, poliolefina y polipropileno) en las propiedades mecánicas de compuestos de yeso-caucho de neumáticos fuera de uso (NFU). Para ello, se elaboran probetas de escayola-caucho NFU con adición de fibras en proporciones del 1% en peso y se caracterizan mediante ensayos físicos y mecánicos estudiando su densidad aparente, resistencia a flexión y compresión y módulo de elasticidad dinámico. Los resultados obtenidos muestran mejoras en todos los aspectos analizados, obteniéndose materiales más ligeros y con mejor comportamiento mecánico especialmente en los compuestos que incorporan fibra de vidrio. Palabras Clave-Escayola; residuos de caucho NFU; fibras de vidrio; fibras de basalto; fibras de polipropileno; fibras sintéticas.

In this article on the basis of analysis of the influence of different technological-environmental parameters, such as the type of cement, water/cement ratio, initial curing temperature, time of conservation work, content of cement, additions, additives and consistency in the evolution of the concrete compressive strength, obtained a calculation equations and some graphs to estimate the resistance evolution of the concrete HA-25/B/20/IIa and HA-30/B/20/ IIa from 3 to 28 days for each initial temperature curing interval specified and for the sample of concrete. So are based on 67782 data of different compressive strength of prepared concrete in the province of Valencia during the years 1996 to 2011, that has allowed to compare the equations obtained from regression with a significant database.

This study aims to study the tracing methods of the ribbed squinches. This typology usually appears to cover spaces of square plan by octagonal plan ribbed vaults, a very common typology in Gothic architecture (chapter houses, funerary chapels and domes, …). For this purpose, two representative cases have been analyzed, with a very similar tracing but different scale: the Chapter House at Valencia Cathedral and the Sala dei Baroni at Castel Nuovo in Naples. The ensuing results left no doubt as to the efficacy of the newly discovered tracing methods and the standardisation of their construction. These results are not only applicable in the renovation of objects of artistic interest but also to prevent any damage to the Cultural Heritage. Key words: Gothic architecture, tracing methods, ribbed squinch, renovation, Valencia Cathedral / Castel Nuovo.