Open Access
Sulfate soils stabilization with magnesium-based binders
(Elsevier, 2016) Seco Meneses, Andrés; Miqueléiz Jiménez, Luis; Prieto Cobo, Eduardo; Marcelino Sádaba, Sara; García, Beñat; Urmeneta, Pablo; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Sulfate soils' stabilization is a very interesting subject with technical, economic and environmental implications. The difficulty of their stabilization is due to the fact that the usual stabilizer additives are based on calcium. In these soils, sulfate combines with the calcium from the additive and the aluminum from the clay, resulting in a highly hydrated expansive mineral named ettringite. This provokes the swelling of the treated material and even its destruction. This study analyzes the result of the substitution of the calciumbased additives by one alternative additive based on magnesium, an industrial byproduct named PC-8, in the stabilization of five different sulfate soils. From a mechanical point of view soils treated with PC-8 reached similar resistance values to the lime treated ones, of about 2–3 MPa for 4% dosage and 2–5 MPa for 8% dosage, being usually better with the PC-8 results than with the lime ones. When PC-8 was combined with GGBS the resistance values increased up to 11–13 MPa and the lime-GGBS reached the 6–7 MPa. The natural swelling of the soils treated with PC-8 decreased substantially and maintained constant even for immersion at long-term. In the case of the soils treated with lime, long-termswelling increased up to very high values even in the case of soilswithout natural swelling. XRD analysis of these samples demonstrated the existence of ettringite in 4 of the 5 soilswhen theywere treated with lime and there was not expansive minerals in the PC-8 treated soils, agreeing with the swelling observed behavior of the soils when treated with both additives.
Open Access
Experimental study of the valorization of sulfate soils for use as construction material
(MDPI, 2022) Seco Meneses, Andrés; Del Castillo García, Jesús María; Perlot, Céline; Marcelino Sádaba, Sara; Prieto Cobo, Eduardo; Espuelas Zuazu, Sandra; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This article shows an experimental investigation carried out for the stabilization of a sulfate soil. The stabilization was carried out in two phases: the first phase was the consumption of the sulfate present in the soil through its controlled transformation into ettringite. After this, a modified soil with lower maximum density, greater optimum moisture identified via standard proctor (SP) test, no plasticity and improved unconfined compressive strength (UCS) was obtained. In the second phase, the modified soil was stabilized by the use of different additives rich in oxides of calcium or magnesium, combined with by-products or waste materials containing reactive aluminum or silicon oxides. As a result, the mechanical strength of the modified soil was improved. In this phase, a binary binder composed of a magnesium oxide product and ground granulated blast-furnace slags (GGBS) obtained the highest UCS. The binary binder composed of lime and an alumina filler formed ettringite in the treated soil. This experiment allowed for the validation of a two-phase stabilization process and the non-conventional additives used, mainly magnesium oxide and GGBS, even for high-bearing-requirement pavement layers’ construction.
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
Technical and environmental characterization of hydraulic and alkaline binders
(Elsevier, 2018) Espuelas Zuazu, Sandra; Echeverria Lazcano, Angel María; Marcelino Sádaba, Sara; Prieto Cobo, Eduardo; Seco Meneses, Andrés; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak; Gobierno de Navarra / Nafarroako Gobernua, 0011-1365-2017-000176
Portland cement is a widely used binder in construction and building applications because of its good properties. Despite its convenience as construction material, the social demands and policies trends are requesting a lower impact and more sustainable cement manufacturing industry. The most effective ways to reach this goal are the substitution of clinker by different wastes or by-products in the cement composition or the development of more sustainable binders like the alkali activated binders. This work analyzes from a technical and environmental point of view the substitution of a clinker based CEM I common cement for the construction mortars manufacturing. Four common cements with different ground granulated blastfurnace slags (GGBS) or fly ashes (FA) contents as well as fifteen alkali activated binders (AAB) combinations were considered. Fresh consistency, density, compressive strength (CS) tests and life cycle analysis were carried out to state the ability of these different hydraulic and alkaline activated binders for the CEM I substitution. The results obtained demonstrated the technical and environmental convenience of these binders for the construction mortars manufacturing.
Open Access
A biological insight of hops wastes vermicomposting by Eisenia Andrei
(Springer, 2024) González Moreno, Miguel Ángel; García Gracianteparaluceta, Beñat; Marcelino Sádaba, Sara; Prieto Cobo, Eduardo; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The study was conducted to assess the feasibility of using Eisenia andrei earthworms for vermicomposting hop remains from a lupulin extraction enterprises for the brewing industry. Vermicomposting process was conducted within 70 days using hop (Humulus lupulus) wastes blended with horse manure at five different ratios for triplicate in laboratory conditions. Number of worms, cocoons, and hatchlings were observed and recorded weekly as earthworm biomass, population build-up and reproduction biological parameters. The results showed an indirect relationship between the hop content and the growth and reproductive performance of the worms. Notwithstanding this fact, 100% of survival occurred in all combinations. A 50% blend of hop wastes and horse manure is suggested to ensure the optimizing usefulness of E. andrei. In addition, moment of maximum splendour of worm population build-up and reproduction parameters measured was achieved at around 40 or 50 days since the beginning of the test, seeing a clear and widespread decline from that moment.
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
Sustainable unﬁred bricks manufacturing from construction and demolition wastes
(Elsevier, 2018) Seco Meneses, Andrés; Omer, Joshua; Marcelino Sádaba, Sara; Espuelas Zuazu, Sandra; Prieto Cobo, Eduardo; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak
The management of construction and demolition wastes is a huge challenge for most Governments. Thegreatest component of such wastes is concrete and masonry fragments or remains. Among the most com-mon approaches to valorization of such w astes is to convert them to recycled aggregates, however thismay be hampered by low quality of some recycled aggregates compared to natural aggregates. This paperpresents the results of experimental investigation where concrete and ceramic remains were used to par-tially substitute clay soil in producing unﬁred bricks. The bricks were then tested for mechanical strength,water absorption freeze-thaw resistance. Additionally the environmental impact of the bricks wasassessed based on Life Cycle Analysis (LCA). It was established that concrete waste could be used to sub-stitute up to 50% of the clay whereas ceramic wastes could only substitute a maximum of 30% of the clay.Blended bricks made from clay and concrete waste mixes had a lower mechanical strength than thosemade from clay and ceramic waste. As regards water absorption, there was no marked differencebetween the two blends of brick however reduction in water resistance was slightly greater in bricks con-taining concrete waste that in those containing ceramic wastes. Also, tests showed that freeze-thawresistance was greater in bricks blended with concrete wastes than in those incorporating ceramicwastes. Life Cycle analyses demonstrated that it is the binder content in the mix that largely determinesthe environmental impact of the blended bricks. Lastly, it was demonstrated that the most desirable tech-nical and environmental credentials of brick material mixes resulted from using the binder combination:CL-90-S+GGBS 2/8.
Open Access
Vermicomposting of lavender waste: a biological laboratory investigation
(MDPI, 2022) González Moreno, Miguel Ángel; García Gracianteparaluceta, Beñat; Marcelino Sádaba, Sara; Prieto Cobo, Eduardo; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
In the present work, lavender waste, a residue of the essential oil extract industry, was used to feed Eisenia andrei with mature horse manure at ratios of 0:100, 25:75, 50:50, 75:25 and 100:0 on dry weight basis. Vermicomposting was carried out for 70 days in laboratory conditions. Biological parameters such as population build-up, total biomass, mortality and cocoon production were observed and measured. Increasing concentrations of waste affected positively the growth and reproduction of worms in a significant way. The 100% lavender waste combination showed the best cocoon production and even tripled their biomass in the first week. A seed germination test was also made, where no evidence of toxicity was found. The germination index range was, in general terms, above 100. The results indicated that the earthworm E. andrei was able to transform lavender waste into compost and thus play a major role in industrial waste management and apply circular economy.
Open Access
El agrocompostaje como solución basada en la naturaleza para el reciclaje de los residuos orgánicos: experiencia piloto con alumnado de FP
(Universidad Pública de Navarra, 2022) González Moreno, Miguel Ángel; García Gracianteparaluceta, Beñat; Prieto Cobo, Eduardo; Seco Meneses, Andrés; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
Una Solución Basada en la Naturaleza (SBN) puede definirse como aquellas acciones en las cuales se emplean los principios de la naturaleza para dar solución a un problema medio ambiental. El compostaje se podría definir como esa solución natural para la transformación biológica de los residuos orgánicos en un producto de alto valor añadido denominado compost. Por lo tanto, esta técnica de reciclaje permite ‘cerrar el círculo’ en aplicación de una economía circular y contribuir en la lucha frente al cambio climático. Por primera vez en España, a través de la Comunidad Valenciana (ORDEN 4/2022, de 24 de marzo), se ha definido legalmente el agrocompostaje como todo aquel proceso de compostaje de subproductos y residuos procedentes de forma directa o indirecta de la actividad agrícola, ganadera y forestal, incluyendo como ingredientes exógenos a la explotación a aquellos materiales tradicionalmente usados para la actividad agrícola como estiércoles o, destríos y subproductos de la actividad trasformadora de los productos vegetales en el ámbito local y de autoconsumo. La presente comunicación pretende mostrar las conclusiones de la experiencia piloto de agrocompostaje realizada a través de un aprendizaje basado en un caso práctico con alumnado de un centro de formación profesional de la rama agraria desde dos puntos de vista: Por un lado, la parte puramente científico-técnica del proceso, dando a conocer los resultados obtenidos fruto del ensayo de agrocompostaje llevado a cabo con varios productos: subproductos agroindustriales de lavanda y lúpulo y residuos de café, en solitario y mezclados, en diversas proporciones de forma sistemática, con estiércol procedente de la explotación ganadera del propio centro educativo. Y por el otro, una parte más socioeducativa, queriendo mostrar desde un punto más 14 subjetivo, las vivencias, dificultades y preocupaciones del proceso de aprendizaje del alumnado mencionado como ‘maestros compostadores’ durante la duración del ensayo.
Open Access
Estimated and real durability of unﬁred clay bricks: Determining factorsand representativeness of the laboratory tests
(Elsevier, 2016) Seco Meneses, Andrés; Urmeneta, Pablo; Prieto Cobo, Eduardo; García, Beñat; Miqueléiz Jiménez, Luis; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak
This paper presents an analysis of the representativeness of the main laboratory tests and the real dura-bility of earth-based construction materials. For this study, a natural marl soil, mixed with different per-centages of silica sand, was treated with portland cement, hydraulic lime, a mix of lime and groundgranulated blastfurnace slag and other binder composed of a high magnesium oxide waste mixed withground granulated blastfurnace slag. All the combinations were characterized based on the usual dura-bility related laboratory tests as are: maximum density, unconﬁned compressive strength, wetting anddrying, Swinburne accelerated erosion resistance, capillarity water absorption, total water absorptionand freeze/thawing cycles. The results of these tests have been related to the real durability of the sam-ples for eighteen months of outdoor exposure. They revealed the positive effect of sand adding in thematerials durability and the great result of the binder based on magnesium oxide with ground granulatedblastfurnace slag. It was also demonstrated the representativeness of the water absorption test as a dura-bility indicator of earth based construction materials durability.