Characterization of the thermal behavior, mechanical resistance, and reaction to fire of totora (Schoenoplectus californicus (C.A. Mey.) Sojak) panels and their potential use as a sustainable construction material

The extraction and use of construction materials generate an impact on the environment due to human activity. Facing these problems requires the development of new alternatives that support changes toward sustainable construction. The development of materials using natural resources creates an important opportunity to reduce the demand for energy, such as the energy used in manufacturing materials. This will contribute to the reduction of exhausting nonrenewable resources and waste production. The objective of this study is to develop a new kind of thermal insulation out of natural vegetation. In this case, using totora (Schoenoplectus californicus (C.A. Mey.) Sojak), which is an aquatic plant that grows in Lake Titicaca. Panels were made from both shredded and whole totora. These panels could be used to improve the thermal comfort inside houses in the high Andes region of Peru, where there are extreme variations in temperature. Studies have demonstrated that one of the characteristics of this plant is its low thermal conductivity, which reveals its potential for insulation. Considering which variables exist that affect the thermal efficiency of an insulating material, flexural tests, air permeability, water vapor permeability, and fire resistance tests were done.Peer ReviewedPostprint (published version

La totora como material de aislamiento térmico: propiedades y potencialidades

Una parte importante del impacto ambiental generado por las actividades humanas se debe a la extracción y uso de materiales para la construcción; frente a este problema existe la necesidad de desarrollar nuevas alternativas y se experimenta un cambio hacia la construcción sostenible; el empleo de materiales de origen natural es una oportunidad para reducir significativamente los efectos negativos de la fabricación de los materiales, en particular de los productos derivados del petróleo, como son las emisiones de efecto invernadero (CO2), el consumo de energía, y la liberación de tóxicos al medio, entre otros. Mediante el presente proyecto se busca desarrollar un nuevo aislante térmico de origen vegetal a partir de la totora (Schoenoplectus tatora), planta acuática con presencia en el Lago Titicaca. Los resultados de las diversas pruebas realizadas muestran que este material tiene una baja conductividad térmica, lo que pone en evidencia su potencial aislante. De esta manera surge la posibilidad de aprovechar y potenciar las propiedades de este material de fácil renovación, que podría ser usado para mejorar las condiciones de confort térmico de las viviendas en la zona alto andina del Perú frente a las variaciones de temperatura extremas.An important part of the environmental impact generated by human activity is the extraction and use of construction materials; confronting this issue creates the need to develop new alternatives and to experience change towards sustainable construction. The use of natural resources gives significant opportunity to reduce the negative effects of the material production, especially in petroleum derivate products. These effects being the emission of greenhouse gasses (CO2), the consumption of energy and the emission of toxic substances in the environment, among others. The project aims to address the development of a new thermal insulator from a plant source, the Totora (Schoenoplectus tatora), an aquatic plant present in the Titicaca Lake. The results of various tests show that this material has a low thermal conductivity, which reveals its insulation potential. Therefore, we have the possibility to benefit from, and enhance the properties of this easily self-restoring material. This material could be used to improve the conditions of thermal comfort inside of houses in the Andean high zone in Peru, where they are faced with extreme variations in temperature

Analysis of the thermal performance of elements made with totora using different production processes

Totora (Schoenplectus californicus (C.A. Mey.) Sojak) is a macrophyte that grows in lakes and ponds from California to Chile and some of the pacific islands. This plant has been used by traditional communities around the world for building a wide variety of objects, from handicrafts and mats, to boats and huts. Totora is a fast growing plant that can produce up to 50 t/ha/year, it can be harvested every 6 months, it has phytodepuration capabilities among other characteristics that make it an interesting material from a sustainable point of view. The internal structure of totora stems is made of the aerenchyma tissue, which is formed by thin cell walls that enclose air chambers. This tissue makes totora stems flexible and prevents the flood of internal organs of the plant. Because of this spongy tissue and the internal arrangement of air chambers, totora can be used as a natural thermal insulation material with low environmental impacts. In this study, the thermal performance of different elements made using totora stems with different production methods is analyzed. Thermal conductivity values vary from 0.05 W/(m.K) to 1.1 W/(m.K) depending on the density of the boards and the methods used to produce them. Totora boards made using crushed totora stems showed lower thermal conductivity than boards made with whole stems. Totora binderless boards showed higher thermal conductivity as their density increase