Improvement of fire reaction and mould growth resistance of a new bio-based thermal insulation material

In the present paper, the performance of an innovative thermal insulation rigid board is evaluated in terms of fire behaviour and fungal resistance. The board is based on vegetal pith and a natural gum (corn pith and sodium alginate) and it is completely compostable. This new composite was developed in previous work. Here boric acid, aluminium hydroxide and ammonium polyphosphate are used as fire retardants and montan wax, acetic acid and lactic acid are used as water repellent and fungicides respectively. Interactions between these different treatments is investigated. Both flaming and smouldering combustion processes of the different formulations are evaluated by small-scale techniques which include pyrolysis microcalorimetry and thermogravimetric analysis. A medium-scale device is also designed in order to study the impact of the different additives to the smouldering kinetics. Fire behaviour tests show that good improvement is obtained, both in flaming and smouldering combustion when boric acid is added. Although smouldering is not avoided in any case, the addition of 8% of boric acid or aluminium hydroxide slows down the speed of combustion propagation. The effect of the different additives on the moisture content and mould growth at 97% RH and 27 °C is analysed. Under such severe conditions none of the additives is able to prevent mould growth, with the exception of boric acid. None or marginal mould growth was observed on samples containing 8% of boric acid although moisture content was higher than the other cases.Peer ReviewedPreprin

El Forn de raig

Recuperación y puesta en valor de un horno tradicional para producción de calPeer Reviewe

El guix tradicional

Coneguem un material que antigament tenia unes característiques ben diferents a les del guix actual.Peer ReviewedPostprint (published version

Pinturas a base de cal: revisión del mercado y acotación normativa

finales de los años 70 la sociedad comenzó a tomar conciencia de los peligros de la pintura sintética con respecto a la salud y a la contaminación ambiental, lo que le hizo volver la vista hacia productos tradicionales “saludables” y que dejan una menor huella en el medio ambiente (como las pinturas minerales, y más específicamente, las pinturas a base de cal). En este artículo se describe de forma breve la historia de este material para luego definir la diferencia entre una pintura a la cal moderna y una pintura de cal tradicional. A continuación, se repasan las normas para saber qué exigencias se le pide a este producto tradicional hoy en día. Finalmente, se analizan las fichas técnicas de pinturas a la cal que se comercializan en Europa, en donde se observa que en pocas ocasiones se aplica la clasificación estipulada por la norma EN 1062-1 (EUROPEAN..., 2004) sobre pinturas y barnices y la directiva 2004/42 CE (DIARIO..., 2004) [ANGLÈS] In the late 1970's, society started to be aware of the health and environmental risks posed by synthetic paints. Those issues motivated a search for traditionalPeer ReviewedPostprint (published version

Physical-mechanical comparison of the traditional gypsums from Albarracín and Pallars

The traditional gypsum of Albarracín is probably the only one currently marketed in Spain. In the Pyrenees of Lleida, specifically in the regions of Pallars Jussá and Pallars Sobirá, the traditional constructions are carried out, mainly with traditional plaster. In order to obtain a traditional gypsum that presents properties similar to those of Albarracín, a traditional oven was built in the Pyrenees of Lleida in 2016, in Senterada (Pallars), obtaining a product of 500 Kg of plaster after cooking. The present work shows a comparative through an experimental study, at a physical-mechanical level, of the two traditional gypsums, with different water/plaster dosages and with different mixing times. The results show many similarities between both materials and demonstrated, once again, how the manufacturing factors can affect them.Peer ReviewedPostprint (published version

Characterization of the fire behaviour of tropical wood species for use in the construction industry

It is widely acknowledged that wood is a combustible and flammable material. However, not all woods have the same fire behaviour; this can change significantly depending on the type and species of wood. Usually, hardwoods have better fire behaviour in comparison with softwoods. This is often due to their physical structure (morphology), their density and hardness and also their moisture content. However, in some cases the main cause is their chemical composition. Some tropical woods with relatively low density present better fire behaviour than other with high density. This indicates that other aspects such as the content of extracts, exudates (oils, waxes, mucilage, tannins etc.) and minerals can greatly influence their fire performance. In this study, seven Mexican tropical wood were characterized in order to determine their fire behaviour. For this purpose, an extensive series of laboratory tests were conducted. The results show a different behaviour in all the species studied, in some cases, with very significant differences. It is observed that although there is some correlation between high density and hardness of the species and their good fire behaviour, these factors are not always determinant. In some species, other factors as anatomy and composition of wood are more relevant to achieve a better fire behaviour.Peer ReviewedPostprint (published version

Correlación de NDT versus resistencia a compresión en tapia

En España se ha abandonado el uso de la tierra como material de construcción debido a las connotaciones asociadas a la pobreza y a la carencia de normativa reguladora. Sin embargo, el amplio patrimonio construido en tierra requiere de los avances en investigación para su conservación, rehabilitación y uso en obra nueva. Debido al vacío tanto en normativa como en literatura sobre cómo determinar el comportamiento mecánico de los muros de tapia existentes, la presente investigación plantea como objetivo final una metodología para determinar la resistencia a compresión de muros de tapia mediante la realización de ensayos no destructivos. A tal efecto, y análogamente al hormigón, se propone la utilización de la correlación entre la densidad aparente, la humedad real, la resistencia a compresión y el ensayo de rebote de impacto, determinados en laboratorio. Este artículo presenta los ensayos no destructivos y destructivos llevados a cabo y se centra en los logros y errores encontrados durante el desarrollo de los mismos, experiencia que puede ser de gran utilidad al resto de investigadores del mismo campo para evitar posibles problemáticas comunes.Peer ReviewedPostprint (published version

The importance of water in traditional gypsum works

[EN] Until the second half of the 20th century, the traditional architecture of the Iberian Peninsula was directly linked to the resources available in its immediate surroundings, naturally diversification the built heritage throughout the territory. In its gypsiferous areas, we find a great versatility of construction systems in which the main binder used is traditional gypsum, although this material has been forgotten in the 20th and the 21st century architecture, meanwhile industrial gypsum currently plays a secondary role in the construction sector. Gypsum, like any traditional binder, is a material that is particularly sensitive to the amount of water with which it is mixed, which will be strongly linked to the technique of application, among other technological parameters. Thus, the final performance of the product is, among other things, a consequence of this water/gypsum ratio, as Francisco Arredondo states in some of his works. In them, the behaviour of an industrial gypsum is analysed as a function of the mixing water, relating it in turn to other parameters such as compressive strength, water absorption and bulk density. The aim of this work is to study the influence of the mixing water on the physical and mechanical properties of different traditional plasters, taking into account previous studies, the diversity of traditional uses of gypsum and current application techniques.This work gratefully acknowledges the support of Universitat Politècnica de Catalunya for the support under a PhD studentship FPI-2018.González Sánchez, B.; Salazar Chuquimarca, W.; Rosell Amigó, JR.; Navarro Ezquerra, A. (2022). The importance of water in traditional gypsum works. En Proceedings HERITAGE 2022 - International Conference on Vernacular Heritage: Culture, People and Sustainability. Editorial Universitat Politècnica de València. 369-375. https://doi.org/10.4995/HERITAGE2022.2022.1530336937

The importance of water in traditional gypsum works

Until the second half of the 20th century, the traditional architecture of the Iberian Peninsula was directly linked to the resources available in its immediate surroundings, naturally diversification the built heritage throughout the territory. In its gypsiferous areas, we find a great versatility of construction systems in which the main binder used is traditional gypsum, although this material has been forgotten in the 20th and the 21st century architecture, meanwhile industrial gypsum currently plays a secondary role in the construction sector. Gypsum, like any traditional binder, is a material that is particularly sensitive to the amount of water with which it is mixed, which will be strongly linked to the technique of application, among other technological parameters. Thus, the final performance of the product is, among other things, a consequence of this water/gypsum ratio, as Francisco Arredondo states in some of his works. In them, the behaviour of an industrial gypsum is analysed as a function of the mixing water, relating it in turn to other parameters such as compressive strength, water absorption and bulk density. The aim of this work is to study the influence of the mixing water on the physical and mechanical properties of different traditional plasters, taking into account previous studies, the diversity of traditional uses of gypsum and current application techniquesPeer ReviewedPostprint (published version

Rammed earth walls in Mediterranean climate: material characterization and thermal behaviour

Rammed earth is considered a very sustainable construction system due to its low embodied energy, long service life and high recyclability. However, authors found that there is a lack of experimental results at real scale regarding rammed earth thermal behaviour. For this reason, this paper is first focused on the characterization of two different types of earth in order to check the suitability of being used in rammed earth walls. After the characterization, two experimental cubicle-shape buildings were built in Barcelona and Puigverd de Lleida (Spain) in order to test the thermal behaviour of their walls in two different climatic conditions. Temperature profiles inside walls have been monitored using thermocouples and temperature profile of southern walls was analysed in free floating conditions during summer and winter periods of 2013. Results show that thermal amplitude from outside to inside temperatures are decreased by rammed earth walls, achieving constant temperatures in inner surface of southern walls.The work was partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER)), in collaboration with the City Hall of Puigverd de Lleida. The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). This project has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under Grant agreement Nº PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES). Barcelona cubicle has been conducted under the direction of the company Casa S-Low, with the collaboration of Luis Allepuz y Cristian Poza in their final degree project at EPSEB (UPC)