Open Access
Durability of polyester polymer concretes based on metallurgical wastes for the manufacture of construction and building products
(Elsevier, 2020) Seco Meneses, Andrés; Echeverria Lazcano, Angel María; Marcelino Sádaba, Sara; García, Beñat; Espuelas Zuazu, Sandra; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería
Varied target materials can be incorporated into polyester polymer concretes (PPC). This allows natural aggregates to be substituted for different waste products in non-structural polymeric construction and building materials. Many studies have explored the mechanical properties of waste-based PPC, but the durability and surface resistance of these materials is not fully known. In this study, we compared the suitability of two metallurgical wastes to that of two natural aggregates for manufacturing durable PPC products. Durability against environmental conditions, durability against chemical products, and surface strength against physical damage were tested. Durability against environmental conditions was characterised according to visual damage and mechanical strength losses after freezing-thawing; no PPC combinations exhibited surface damage following the ageing cycles. The ladle slag (LS) samples exhibited the best pre- and post-test flexural and compressive strength. The properties of the alumina filler (AF) combinations exhibited the highest flexural and compressive strength losses after freezing-thawing. The calcareous sand combinations were damaged most severely by acid, while LS and AF exhibited good resistance against chemical substances. The LS combinations exhibited the highest surface strength against impacts in the rebound number test, while the results obtained for the AF combinations were close to those of natural aggregates. The surface resistance against scratching depended on the resin, not on the target material.
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
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
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
Characterization of biomass briquettes from spent coffee grounds and xanthan gum using low pressure and temperature
(Springer, 2020) Seco Meneses, Andrés; Espuelas Zuazu, Sandra; Marcelino Sádaba, Sara; Echeverria Lazcano, Angel María; Prieto Cobo, Eduardo; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Gobierno de Navarra / Nafarroako Gobernua
This paper analyzes the ability of the SCG for briquettes production based on the use of xanthan gum as binder under low-pressure and low-temperature biomass manufacturing conditions. Briquettes were manufactured at room temperature, at 10, 15, 20, 25, and 30% of moisture content and 8, 10, and 12 MPa of compaction pressure. Raw SCG samples reached dry densities between 0.669 and 0.735 g/cm3 for the samples with a moisture content of 15% and 8 MPa and 10% and 12 MPa, respectively. Samples treated with 10% of xanthan gum got densities between 0.672 and 0.819 g/cm3 depending on the moisture content and the compaction pressure. No one of the raw SCG combinations passed the durability test meanwhile xanthan ones with 30% of moisture content obtained the best results with a loss of mass of 9.1% for the combination compacted at 10 MPa. Raw SCG samples showed water absorption values between 0.498% and 0.846%, meanwhile xanthan samples water absorption oscillated between 0.427% and 1.065%. Xanthan gum increased the SCG ashes content from 0.66% to 0.97% and decreased the lower heating value (LHV) from 25,399 J/g of the pure raw SCG to 23,503 J/g. Thermogravimetric tests showed that xanthan gum mix compared to the raw SCG increased as well the volatile peak from 61.54 mW to 81.94 mW as the mass loss rate in the volatile stage from −0.0178 mg/s to −0.0184 mg/s.