Embargo
Development of sustainable stabilized rammed earth building materials based on by-products
(2025) Martín Antunes, Miguel Ángel; Bascoules Perlot, Céline; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
En esta tesis doctoral, se desarrolló un material basado en subproductos locales para su uso como material de construcción de Tapial Estabilizado (SRE) en el sector de la construcción. Los materiales considerados como subproductos son producidos localmente dentro de la Eurorregión, específicamente en Navarra. El material desarrollado en la tesis doctoral constituye una aplicación para estos subproductos, que carecen de formas efectivas de valorización, evitando su disposición en vertederos, reduciendo los costos de gestión y ahorrando recursos naturales. Además, ayudaría al sector de la construcción de la Eurorregión a mitigar su huella ambiental. La ejecución del proceso de investigación requerido para el desarrollo de esta tesis doctoral se llevó a cabo utilizando una metodología dividida en cuatro fases. En la primera fase, se realizó una revisión bibliográfica exhaustiva sobre SRE. A través del análisis de la información recopilada, se propuso una metodología para la fabricación, curado y caracterización del material de construcción SRE. Esta metodología se aplicó en las siguientes fases de investigación que constituyen esta tesis doctoral. En la segunda fase, se identificaron y caracterizaron los subproductos locales con potencial para su uso en la construcción de SRE, con el fin de desarrollar una mezcla de subproductos naturales que pudiera reemplazar el suelo en la construcción de SRE. Se consideraron cuatro subproductos (tres diferentes subproductos mineros con diferente granulometría y un subproducto industrial, arena) como componentes de esta mezcla. Se llevó a cabo una campaña experimental para establecer las proporciones adecuadas para combinarlos en una mezcla optimizada adecuada para su uso en la construcción de tierra compactada mediante el modelo de diseño experimental Taguchi. Este método estadístico se aplicó para estudiar el efecto de diferentes distribuciones de tamaño de partículas (PSDs) en la construcción de tierra compactada, con el objetivo de maximizar la densidad en seco del material y la resistencia a compresión no confinada (UCS). En la tercera fase se decidió estabilizar la combinación en la que la PSD optimizó la densidad en seco con tres estabilizadores convencionales diferentes: cemento, cal hidratada calcárea y cal hidráulica natural. En la cuarta fase, con el fin de reducir el impacto ambiental de los estabilizadores convencionales, se estabilizó el material con PSD optimizada utilizando dos estabilizadores no convencionales diferentes. Se caracterizaron sus propiedades mecánicas y de durabilidad, siguiendo la metodología de la primera fase, y se compararon con las propiedades de SRE obtenidas con estabilizadores convencionales. Los estabilizadores no convencionales estudiados fueron un estabilizador basado en Mg (GGBS-PC8) y un cemento supersulfatado (SSC). Se realizaron dos campañas experimentales diferentes, donde se fabricaron seis combinaciones que fueron sometidas a pruebas de UCS, UCS sumergido, pruebas de durabilidad por humedecimiento y secado, SEM/EDS, TG/DTG y XRD. Las combinaciones estabilizadas con los estabilizadores no convencionales lograron mejores resultados que aquellas estabilizadas con los convencionales. Estos resultados demostraron el potencial de los estabilizadores no convencionales, los cuales, en el caso del GGBS-PC8, permitieron el desarrollo de un material de construcción 100% basado en materiales reciclados con propiedades técnicas y ambientales mejoradas.
Open Access
Valorization of mining by-products for rammed Earth construction
(Springer, 2024-07-27) Martín Antunes, Miguel Ángel; Seco Meneses, Andrés; Perlot, Céline; McGregor, F.; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Mining and manufacturing produce large amounts of waste. One effective way for the valorization of many inert wastes or by-products from these industries is their use for the development of sustainable construction materials. This work analyzes the ability of different mix proportions of two by-products from mining, a mining clayed sludge, and a spent foundry sand, for the formulation of a by-products based rammed earth construction material. To achieve this objective an experimental laboratory campaign was developed. First, the physic-chemical properties of both by-products were measured, and the geotechnical properties of clayed sludge especially clay content and granulometry were evaluated. Then, these four by-product materials were combined to create three different combinations of soils with continuous granulometric curves, adequate for rammed earth construction, following the available literature. A Standard Proctor test was carried out to determine the optimum dry density and optimal water content of the mixes. Then, the mechanical strength was characterized by Unconfined Compressive Strength (UCS) tests. The proportions of the materials with higher bulk density show a direct relationship with the UCS values obtained. Water immersion was considered for the characterization of the durability of the developed material. During the durability test, the samples lost their integrity. This work shows the ability of these by-product mixes to produce even more sustainable rammed earth constructions with 100% of recycled constituents, achieving the mechanical strength requirement, not durability ones. Further investigations are required to improve this by-product made soil durability performance.
Open Access
Recovered foam impact absorption systems
(MDPI, 2024-10-19) Marcelino Sádaba, Sara; Benito Hernández, Pablo; Martín Antunes, Miguel Ángel; Villanueva Roldán, Pedro; Veiga Suárez, Fernando; Ingeniería; Ingeniaritza
The use of foam materials in environments where they come into contact with individuals often results in deterioration, necessitating periodic replacements to maintain safety and hygiene standards. Foam, a lightweight, porous plastic formed by aggregated bubbles, possesses excellent impact-absorbing properties; however, its inherent porosity and susceptibility to wear present challenges. This project aims to develop a technological application for repurposing spent polyurethane (PU) foam from leisure facilities into effective impact absorption systems. By focusing on the reuse of deteriorated foam materials, this initiative seeks to minimize environmental impact while leveraging their beneficial technical characteristics. Addressing issues related to foam degradation, this project endeavors to create sustainable solutions by reintegrating spent foam into new systems. This innovative approach promotes sustainability while enhancing safety through the provision of high-quality, impact-resistant elements. Ultimately, this work aims to contribute to environmental conservation and the advancement of effective impact protection measures in leisure facilities.
Open Access
Evaluation of the potential of natural mining by-products as constituents of stabilized rammed earth building materials
(MDPI, 2025-05-06) Martín Antunes, Miguel Ángel; Perlot, Céline; Villanueva Roldán, Pedro; Abdallah, Rafik; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this investigation, different natural by-products were used to modify the Particle Size Distribution (PSD) of a soil to evaluate their potential in Stabilized Rammed Earth (SRE) building. Three different mixes were manufactured: (i) a mix composed entirely of a clayey soil, (ii) a mix consisting of mining by-products and clayey soil and (iii) a mix entirely based on mining by-products. Unstabilized and stabilized samples of the mixes were manufactured using two cement dosages (2.5% and 5%), and the samples were tested for Unconfined Compressive Strength (UCS), soaked UCS, and wetting and drying tests. Mining by-products demonstrated significant potential in SRE building, as their addition to the clayey soil resulted in higher UCS values compared to the UCS obtained from clayey soil alone. Unstabilized samples lost their integrity during exposure to water. The inclusion of mining by-products also showed potential as, although the mixes did not fully meet the requirements for soaked UCS and the wetting and drying tests, the mix containing both mining by-products and clayey soil retained its integrity in water, unlike the samples composed solely of clayey soil. M3C5 successfully met the requirements for soaked UCS and the wetting and drying tests, further highlighting the great potential of mining by-products in SRE building.
Open Access
Mechanochemical activation of non-conventional precursors for use as suplementary cementitious materials
(Elsevier, 2025-03-15) Seco Meneses, Andrés; Martín Antunes, Miguel Ángel; Espuelas Zuazu, Sandra; Fernández Jiménez, Ana; Prieto Cobo, Eduardo; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC
This work analyzes the effect of Mechanochemical Activation (MA) of a Commercial low-grade kaolinite and low- grade illite, a feldspar, a diatomite and a clayey soil (non-commercial) as supplementary cementitious materials. Milling was conducted at different times for up to 360 min. MA decreased the particles size and increased the specific surface area except for low-grade illite. However, prolonged milling produced agglomeration in feldspar, diatomite and clayey soil. MA partially reduced diffractogram peaks and modified the dehydroxylation losses of mass in the thermogravimetric tests. MA's effect over the solubility of SiO 2 and Al 2 O 3 was not conclusive, with differences among aluminosilicate minerals and with no relationships with their physical parameters or chemical structures. Feldspar was the only one not to show Strength Activity Index (SAI) increases due to MA. Low-grade illite, feldspar and diatomite combinations surpassed 75 % on the SAI. No clear relationships were observed between the combinations SAI and their physical parameters, chemical structure or SiO 2 and Al 2 O 3 availability.
Open Access
A methodology to optimize natural by-product mixes for rammed earth construction based on the Taguchi method
(MDPI, 2024-11-13) Martín Antunes, Miguel Ángel; Prieto Cobo, Eduardo; García, Beñat; Perlot, Céline; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarrroako Unibertsitate Publikoa
In this investigation, the Taguchi method was employed to optimize a mix based on four natural by-products for rammed earth construction. Two separate studies were conducted to enhance the dry density and the Unconfined Compressive Strength (UCS). The four materials were assessed across four different levels, with moisture content also factored in as a parameter within a statistical analysis of 16 combinations. The Taguchi method predicted the combinations in which the Particle Size Distribution optimized the dry density and UCS as well as their dry density and UCS values. From the results, Moisture Content was the parameter with the highest influence on the optimization as well as the dry density and the UCS. It was observed that there was a direct relationship between the bulk density of the different granulometric fractions and their influence on the mix's dry density. The fines were the material constituents that showed the highest influence on the mix UCS. When using the Taguchi method in RE building, the factor that should be maximized should is the mechanical strength.
Open Access
Fresh, mechanical, and microstructural properties of sustainable mortars made of two recycled sands from construction and demolition wastes
(American Society of Civil Engineers, 2025-04-28) Seco Meneses, Andrés; Martín Antunes, Miguel Ángel; Espuelas Zuazu, Sandra; Marcelino Sádaba, Sara; Prieto Cobo, Eduardo; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
This paper analyses the ability of two recycled sands (RSs) from concrete (CON) and masonry (MAS) wastes for the manufacture of mortars for the construction industry. Manufactured sand (MS) was substituted by both RSs at the rates of 25%, 50%, 75%, and 100%. CON combinations did not demonstrate any correlation between workability and the MS replacement ratio, whereas MAS combinations exhibited a direct relationship between these factors. A decrease in the starting and final setting times was observed for both RS combinations and, in general, longer total setting times. CON combinations showed mechanical strength increases for substitution rates between 25% and 50%, whereas MAS reached improved mechanical strength at 25%. Scanning electron microscopy-energy dispersive X-ray (SEM-EDX)-demonstrated tests allowed for mortar microstructure differences and hydration product formation. Thermogravimetric analysis/derivative thermogravimetry (TG/DTG) tests showed hydrated cementitious compounds' formation differences and the consumption of Portlandite between combinations and their evolution during curing.