Bio-based materials for fire-retardant application in construction products: a review

Bio-based materials are showing great potential to be widely used in construction industry, while reducing fire risk and improving fire resistance of these alternatives also become a major concern due to their inherent flammability. Initially, this review introduces three common bio-based construction materials, including biopolymer-based materials, wood-based materials, and crop-based materials, and their fire behaviors in flaming and smoldering combustion scenarios, accompanied with some typical flame-retardant mechanisms. Sequentially, the recent achievements in improving fire resistance are mainly exhibited in detail for each kind of bio-based materials. There are numerous reports for biopolymer-based flame-retardant materials with mature flame-retardant methodology. With regard to wood-based flame-retardant materials, different criteria and methodologies are needed to evaluate the flame-retardant properties. Meanwhile, in the case of crop-based insulation materials is essential to carefully consider the fire behavior, both in flaming and smoldering combustions, and not only focus on their thermal performance. In the final section, based on the requirements of fire safety and practicality for construction materials, bio-based alternatives with excellent good fire resistance and practical performance are summarized to be a promising way to meet future challengesPeer ReviewedPostprint (author's final draft

Use of wastes to create new building materials

This paper is a teaching activity carried out on the subject of Building Materials from Building Engineering studies. This subject is developed in the second year and lasts for a four month period. The student teacher ratio is around 60:1. The goal of this work was the development of a new building material obtained from waste materials. Students were divided in teams of three students chosen by themselves. This activity helped students to develop knowledge about different materials and make them aware of the importance and possibilities to profit waste materials. Students should work with materials studied in the subject, mainly clay, glass, steel, wood and plastics. Before beginning they must do an important bibliographic research about the topic they wanted to develop. The university provided the use of lab facilities and the guidance of the teacher. Besides following up the work, the teacher encouraged the students to perform some tests on the new material obtained. Finally they should come out with a poster and a sample of the material. Results got from different works differed substantially according to the interest and time dedicated to them. Most of the students abused of the use of polymeric resins to elaborate the new materials, and therefore, even using wastes the new materials were not so sustainable. The use of natural materials such as cane fibres leaded to materials with interesting insulation and structural properties. It was a very good experience to attract students to materials research. Finally we discovered in order to get profitable results, this kind of activity should cover a longer period and should count with the continuous guidance of the teachers.Postprint (published version

Combining research and final degree project: Improvement of the fire behaviour of bamboo. Study in the species Guadua Angustifolia and Phyllostachys Pubescens.

Pozzolanic additions are siliceous or aluminous materials that in the presence of water react with calcium hydroxide and form compounds with cementitious abilities. Despite pozzolans take their name from the volcanic scoria from Puozzoli, they can have different origins. Industrial by-products like fly ash or blast furnace slag show pozzolanic activity and are incorporated in cement formulations. Forest, agricultural and other plant-based residues that are used as biomass leave ashes as a residue. If the amount of ashes is significant and the composition of these ashes is rich in silica it could be an interesting source of pozzolans from a natural and renewable origin. In this abstract it is presented a preliminary study to evaluate the feasibility of different ashes from bio-based origin as pozzolanic material. In this work, there have been obtained and characterized ashes from different plant residues: sun flower rind and pith, corn rind and pith, rice husk, Posidonia oceanica, olive pit, olive tree branches. In order to evaluate the influence of the temperature on the properties of the ashes different calcination methods were used to obtain the ashes. The chemical composition was evaluated by means of X ray fluorescence, the crystalline phases were determined by X ray diffraction and Fourier transform infrared (FTIR) spectroscopy was used to identify the molecules. This step helped us to select the ashes with potential as pozzolan additions for a further investigation. The results show that the use of biomass as a source of pozzolanic additions is possible if some requirements regarding the characteristics of the ashes are achieved.Peer ReviewedObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesPostprint (published version

Bibliometric analysis of research on thermal, acoustic, and/or fire behaviour characteristics in bio-based building materials

The use of bio-based building materials is a sustainable opportunity to reduce the environmental footprint associated with the construction sector. The achievement of this objective is primely achieved through the valorisation of vegetable waste, resulting in a reduction in the use of primary source material and waste generation. Within the scope of this study, the focus is directed towards research concerning the thermal, acoustic, and fire behaviour properties of bio-based building materials. This study conducts a comprehensive bibliometric analysis encompassing all documents meeting these criteria within the Scopus database, spanning two decades, from 2003 to 2023. The comprehensive analysis covered a total of 1081 documents, which were analysed. This analysis furnishes insight into various facets, including the temporal evolution of publications, journals boasting the highest publication counts and impact, influential research areas, countries with substantial contributions and their collaborative patterns, noteworthy affiliations, prolific authors, and seminal documents, alongside recurrent keywords. The objective of this comprehensive study is to provide a detailed analysis of the documents published up to the present day, in order to identify research gaps and potential opportunities in this field, to assist new researchers interested in the subject. The analysis reveals that bio-based building materials have gained substantial attention over the past decade. With each passing year, the published documents have increased their impact and become more specific, underscoring the growing importance of this subject. This evolution has also fostered a broader network of researchers engaged in this field. However, it is noteworthy that the characterization of these materials focuses predominantly on their thermal properties, while research avenues related to acoustic and fire properties remain less explored and present opportunities for future investigation.This work was supported by the Spanish MCIN/AEI/10.13039/501100011033 through the research project BioSAFE (PID2020–117530RB-I00). Also, they want to thank the Generalitat de Catalunya for the quality accreditation given to the research group GICITED (2021 SGR 01405) and the European Union Erasmus+ Programme for the project Bio-Fibre (2022–1-DK01-KA220-HED00086641). B. A-C, gratefully acknowledges receipt the financial support of the Spanish Minister scholarship: “Subprograma Estatal de Formacionó del Programa Estatal para Desarrollar, Atraer y Retener Talento, en el marco del Plan Estatal de Investigación Científica, Técnica y de Innovación 2021–2023”.Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesObjectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.1 - Aplicar el Marc decennal de programes sobre modalitats de consum i producció sos­tenibles, amb la participació de tots els països i el lideratge dels països desenvolupats, tenint en compte el grau de desenvolupament i les capacitats dels països en desenvolupamentObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

Mobility of Architectural Technology and Building Construction students: diagnosis and opportunities

[EN] Internationalization of higher education programmes is a goal pursued by most universities and their corresponding faculties and schools. One of the main indicators to evaluate internationalization is the number of students who complete a mobility program. In this work we carry out an analysis of the evolution of the mobility of Architectural Technology and Building Construction students from the Barcelona School of Building Construction (EPSEB) since 2010 and we compare it with the evolution of mobility in the university. We analyze the main causes that limit the mobility of ATE students and we suggest actions to increase the internationalization of our studies and students.[ES] La internacionalización de los estudios universitarios es una meta que persiguen la mayoría de universidades y sus correspondientes facultades y escuelas. Uno de los principales indicadores para evaluar la internacionalización de los estudios es el número de estudiantes que realizan un programa de movilidad. En este trabajo realizamos un análisis de la evolución de la movilidad de los estudiantes de Arquitectura Técnica y Edificación (ATE) de la Escuela Politécnica Superior de Edificación de Barcelona (EPSEB) desde el año 2010 y la comparamos con la media de la universidad. Se evalúan las principales causas que limitan la movilidad de los estudiantes de ATE y se proponen actuaciones para incrementar la internacionalización de nuestros estudios y estudiantes.Haurie Ibarra, L.; Alastruey Martin, C. (2021). Movilidad de los estudiantes de Arquitectura Técnica y Edificación: diagnóstico y oportunidades. En EDIFICATE. I Congreso de Escuelas de Edificación y Arquitectura Técnica de España. Editorial Universitat Politècnica de València. 653-662. https://doi.org/10.4995/EDIFICATE2021.2021.13606OCS65366

Epsomite as flame retardant treatment for wood: Preliminary study

The effect of epsomite as flame retardant for wood has been investigated and compared with a commercial boron salt. Both flame retardants have been introduced into wood samples by vacuum impregnation. Epsomite is a hydrated sulphate salt with a water solubility of 731 g L-1 at room temperature. Thanks to this high solubility it was possible to obtain elevated epsomite loadings in comparison with the borax salt. Flame retardancy was evaluated by means of the limiting oxygen index, the dripping test and the exposition to a direct flame (Bunsen test). The results showed that the addition of epsomite increases the limiting oxygen index, delays the time to ignition and the evolution of the temperatures trough the wood. © 2016 Elsevier LtdPeer ReviewedPostprint (author's final draft

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

Toxicidad

La toxicidad es una problemática de vital importancia en caso de incendio. Como ha podido verse por casos como el de la Torre Grenfell de Londres, siniestro que motiva la elaboración del presente documento, la inhalación de humos es la principal causa de muerte en estos casos. Pese a ello, las normativas reguladoras en el sector de la construcción no contemplan este factor ni ofrecen soluciones al respecto, como sí ocurre en otros sectores industriales. Debido a esto, en el siguiente capítulo se analizan los diferentes aspectos a tener en cuenta para entender la toxicidad en caso de incendio, además de revisarse la regulación que diferentes países realizan sobre la toxicidad de los humos de los materiales de construcción.Postprint (published version

The components’ roles in thermal stability and flammability of cork powder

In this study, an analysis of the influence of extractives, suberin and lignocellulosic components on the pyrolysis decomposition and fire reaction mechanisms of a cork oak powder from Quercus suber L. is presented. The summative chemical composition of cork powder was determined. Suberin was the main component at 40% of the total weight, followed by 24% of lignin, 19% of polysaccharides and 14% of extractives. The absorbance peaks of cork and its individual components were further analyzed by means of ATR-FTIR spectrometry. Thermogravimetric analysis (TGA) showed that the removal of extractives from cork slightly increased the thermal stability between 200 °C and 300 °C and led to the formation of a more thermally stable residue at the end of the cork decomposition. Moreover, by removing suberin, a shift of the onset decomposition temperature to a lower temperature was noticed, indicating that suberin plays a major role in enhancing the thermal stability of cork. Furthermore, non-polar extractives showed the highest flammability with a peak of heat release rate (pHRR) of 365 W/g analyzed by means of micro-scale combustion calorimetry (MCC). Above 300 °C, the heat release rate (HRR) of suberin was lower than that of polysaccharides or lignin. However, below that temperature it released more flammable gases with a pHRR of 180 W/g, without significant charring ability, contrary to the mentioned components that showed lower HRR due to their prominent condensed mode of action that slowed down the mass and heat transfer processes during the combustion process.Peer ReviewedPostprint (published version

Effect of oxidized wood flour as functional filler on the mechanical, thermal and flame-retardant properties of polylactide biocomposites

Based on the biodegradable material-polyethylene glycol (PEG)-as the plasticizer, oxidized wood flour (OWF) as the charring agent for polylactide (PLA), a series flame-retardant PLA biocomposites were prepared via melt-compounding and hot-compression. The effect of OWF on the thermal, mechanical and flame retardant properties of biocomposites was investigated systemically. We have found that after the incorporation of PEG and OWF with 10¿wt% into PLA, the biocomposite showed higher tensile elongation than pure PLA. Furthermore, the presence of OWF and ammonium polyphosphate (APP) imparted the biocomposite good flame-retardant performance, shown a remarkable reduction on the peak of heat release rate (PHRR), improved LOI value and passed UL94 V-0 rating. Moreover, Scanning electron microscopy-energy dispersive spectra (SEM/EDS) and thermogravimetric analysis coupled with infrared spectrometer (TG-FTIR) were also performed to understand the flame retardant mechanism. These results proved that OWF could be as new functional filler for polymer composites to further improve their flame retardancy.Peer ReviewedPostprint (published version