Open Access
Sulphate soil stabilisation with magnesium binders for road subgrade construction
(Taylor and Francis, 2020) Seco Meneses, Andrés; Espuelas Zuazu, Sandra; Marcelino Sádaba, Sara; García, Beñat; Del Castillo García, Jesús María; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Gobierno de Navarra / Nafarroako Gobernua
This paper analyzes the ability of magnesium oxide-based additives to stabilise a low bearing gypsum marly soil, in order to reach subgrade requirements. This soil was not adequate for stabilisation with lime or cement because of its high sulphate content. Binders considered in this investigation were composed of three reactive Mg products and by products, both with and without ground granulated blast furnace slags (GGBS). They were compared to two cements and an aerial lime as soil stabilisers in a laboratory investigation and a field trial. Laboratory tests showed that Mg products with GGBS reached strength results close and at times even better than those of cement. One of the Mg products was the only additive able to reduce the natural soil swelling. Leaching tests demonstrated the ability of the Mg products to reduce the soil leaching of substances like calcium, magnesium, sulphate and chloride. In field trials two of the Mg products combined with GGBS met the bearing capacity requirements for subgrades, in accordance with the Spanish standard.
Open Access
Recycled granulates manufacturing from spent refractory wastes and magnesium based binder
(Elsevier, 2023) Seco Meneses, Andrés; Del Castillo García, Jesús María; Perlot, Céline; Marcelino Sádaba, Sara; Espuelas Zuazu, Sandra; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC
This paper analyzes the ability of two Spent Refractory Wastes (SRW) for the manufacturing of recycled granulates for construction applications. A binary magnesium oxide and ground granulated blast furnace slag hydraulic binder was considered as an agglomerating agent for the granulates manufacturing. Influence of curing atmosphere was carried out: in air, 20 % CO2 and 100 % CO2 atmosphere up to 28 days. Granulometry, thermal analysis, particle density, bulk density, water absorption and mechanical strength tests were performed to characterize the granulates. SRW showed their ability for the granulates manufacturing. Results demonstrated the existence of a residual reactivity of the wastes considered. A direct relationship between the CO2 content of the curing atmosphere and the granulates hydration degree was observed. Carbonation process increased from 7 days to 28 days and direct relationships were observed between the CO2 content and the carbonation degree as well as between the binder dosage and the carbonation degree. CO2 curing reduced the water absorption and increased the compressive strength of the granulates.
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
Stabilization of a clay soil using cementing material from spent refractories and ground-granulated blast furnace slag
(MDPI, 2021) Seco Meneses, Andrés; Del Castillo García, Jesús María; Espuelas Zuazu, Sandra; Marcelino Sádaba, Sara; García Gracianteparaluceta, Beñat; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC
Nowadays, huge amounts of refractory materials are generated around the world. The majority of them lack valorization methods. This study analyzes the ability of a doloma and two magnesia spent refractory wastes as soil stabilizers on their own, as well as when combined with Ground-Granulated Blast Furnace Slags (GGBS). These materials showed a limited ability for the soil’s plasticity modification from a plasticity index of 15.6 to a minimum of 12.7. The high pH of the additives increased the soil’s pH from 7.88 to values in the range of 10.94–11.25 before the 28 days, allowing the development of the pozzolanic reactions. Unconfined compressive strength (UCS) increased along the curing time, reaching a maximum value of 5.68 MPa after 90 days. Based on the UCS, the optimum refractory GGBS ratios oscillate between 30:70 and 50:50. The UCS values after soaking samples reduced the unsoaked results between 68.70% to 94.41%. The binders considered showed a low effect against the soil swelling and the lack of delayed expansive effects because of the MgO hydration. Finally, X Ray Diffraction (XRD) tests showed that the stabilization only slightly modified the combinations of mineralogy and the formation of Magnesium Silicate Hydrate (MSH) gels.
Open Access
Magnesium oxide as alternative binder for unﬁred clay bricks manufacturing
(Elsevier, 2017) Espuelas Zuazu, Sandra; Omer, Joshua; Marcelino Sádaba, Sara; Echeverria Lazcano, Angel María; Seco Meneses, Andrés; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Replacement of ﬁred bricks by unﬁred ones could be an eﬀective way to reduce the building industryenvironmental footprint: Their manufacture not only requires less energy and natural resources but alsogenerates less waste. Bricks are based on the use of an additive cementitious material in the form of a binder,usually lime or cement. Such additives have a great environmental impact owing to the high energy consumptionand CO2during in their manufacturing process. In this article experiments are carried out in order to investigatethe applicability of a MgO rich industry by-product as a binder for the production of unﬁred clay bricks. Fromthe experiments, the MgO was observed to show ability to enhance the mechanical properties of a clay brick inmuch the same way as lime does. Water absorption tests on bricks revealed the superiority of MgO over lime inenhancing the durability properties of unﬁred bricks. The laboratory results demonstrate the high potential ofMgO based additives as alternative binders to the calcium based ones. Consequently, this oﬀers opportunity forreducing the environmental impact associated with the use of ﬁred clay bricks. In addition, it could allow aneﬀective way for the valorization of MgO containing industry by-products that currently discarded to landﬁlls
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
Characterization of fresh and cured properties of polymer concretes based on two metallurgical wastes
(MDPI, 2020) Seco Meneses, Andrés; Echeverria Lazcano, Angel María; Marcelino Sádaba, Sara; García, Beñat; Espuelas Zuazu, Sandra; Institute of Smart Cities - ISC
Polyester polymer concretes can substitute conventional concretes based on their usually good mechanical strength, adequate physical properties, and high resistance against aggressive chemical environments. They also show a high potential for using recycled targets in their manufacturing. This paper analyzes the fresh and cured properties of polyester polymer concretes containing two metallurgical wastes, namely: ladle slag and alumina filler. Both targets require a higher resin dosage than sand. The standard consistency test showed a low representativeness of the recycled fresh mixes’ workability. The ladle slag and alumina filler samples showed a higher length plastic shrinkage than those containing sand. All of the targets obtained cured density values in the range of 1.589–1.912 g/cm3. From a mechanical point of view, the sand and alumina filler containing polyester polymer concretes reached 11.02 and 10.93 kN, respectively, of flexural strength, while the ladle slag samples showed the best result with 19.31 kN. In the compressive strength test, the sand and alumina filler combinations reached 106.16 and 104.21 MPa, respectively, while the ladle slag achieved 160.48 MPa. The flexural and compressive elasticity modulus showed similar trends related to the resin content.
Open Access
Assessment of the ability of MGO based binary binders for the substitution of Portland cement for mortars manufacturing
(Elsevier, 2022) Seco Meneses, Andrés; Espuelas Zuazu, Sandra; Marcelino Sádaba, Sara; Echeverria Lazcano, Angel María; Del Castillo García, Jesús María; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Gobierno de Navarra / Nafarroako Gobernua
This article evaluates the ability of a magnesia kiln dust (PC-8) and a commercial calcined MgO (MCB100), combined with ground granulated blastfurnace slag (GGBS), as constituents of binary M-S-H binders. Mortars and pastes were manufactured and their properties were compared to those of Portland Cement (PC). MgO-based mortars showed an increase in setting time and higher fresh consistency. At earlier ages MgO mortars showed lower mechanical properties. At 90 days both MgO-based mortars overcame the PC flexural strength and PC-8 + GGBS also overcame its compressive strength. X-Ray Diffraction and Thermogravimetry tests demonstrated the presence of M-S-H in the pastes.
Open Access
Low energy spent coffee grounds briquetting with organic binders for biomass fuel manufacturing
(Elsevier, 2020) Espuelas Zuazu, Sandra; Marcelino Sádaba, Sara; Echeverria Lazcano, Angel María; Seco Meneses, Andrés; Del Castillo García, Jesús María; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Gobierno de Navarra / Nafarroako Gobernua
This paper analyzes the ability of the spent coffee grounds (SCG) for briquettes production with xanthan and guar gums as binders. Briquettes were manufactured at room temperature, at 15%, 20%, 25% and 30% of moisture, at 8 MPa, 10 MPa and 12 MPa of compaction pressure and at 5 and 10% of binder dosage. Combination of 10% of xanthan, 15% of moisture, at 12 MPa, reached the highest dry density, 0.819 g/cm3. The combination of 5% of xanthan, 30% of moisture, compacted at 12 MPa was the most durable with a loss of mass of 3.9%. No relationships were established among water absorption and binder type, binder dosage, manufacturing moisture or compaction pressure. The lowest water absorption value, 0.25%, corresponded to the combination with 5% of xanthan, 30% of moisture, compacted at 10 MPa. The lowest heating value achieved by SCG was 25,399 J/g. Guar 5% and 10% combinations achieved 24,398 J/g and 24,321 J/g respectively. Xanthan gum 5% and 10% dosages attained 24,450 and 23,503 J/g. Binder decreased volatiles, increased fixed carbon content and decreased nitrogen content. Guar gum decreased SCG nitrogen content by 15.92% for the 5% and by 16.92% for the 10% dosage combinations, respectively. Xanthan nitrogen reduction attained 13.43% for the 5% and 14.43% for the 10% of dosage. The raw SCG ash production was 0.66%. This value increased to 0.81% and 0.97% with 5% and 10% of xanthan gum, meanwhile guar decreased it to 0.57% and 0.52%, at 5% and 10% of dosage.
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.