Articles de revistahttp://hdl.handle.net/2117/222092024-03-28T18:52:33Z2024-03-28T18:52:33ZPreparation of a cyclotriphosphazene microsphere bearing a phosphaphenanthrene structure towards fire-safety and mechanical enhancement for epoxy and its aramid fiber compositeYang, YunxianZhang, QiHao, YiwenLan, XukeHaurie Ibarra, LaiaZheng, DezhiHuang, Guangyanhttp://hdl.handle.net/2117/4049952024-03-25T01:44:36Z2024-03-20T09:33:43ZPreparation of a cyclotriphosphazene microsphere bearing a phosphaphenanthrene structure towards fire-safety and mechanical enhancement for epoxy and its aramid fiber composite
Yang, Yunxian; Zhang, Qi; Hao, Yiwen; Lan, Xuke; Haurie Ibarra, Laia; Zheng, Dezhi; Huang, Guangyan
The mismatch of flame retardancy and mechanical properties is still a challenge for developing high-performance epoxy resin (EP) and its aramid fiber (AF) composite. In this study, a multifunctional cyclotriphosphazene microsphere EHP modified by a phosphaphenanthrene structure was prepared to solve the issue by taking advantage of multiple flame-retardant actions and interfacial interaction. After introducing EHP into epoxy resin, the thermoset exhibited good thermal stability, excellent flame retardancy and enhanced mechanical properties. Especially for sample EP/3%EHP with only 0.39 wt% P-loading, the limiting oxygen index (LOI) value increased from 25.5% to 33.5% accompanied by the V-0 rating in the UL-94 test; besides, the heat release and smoke release behaviors were also inhibited. Additionally, the tensile and impact strengths of the same epoxy sample increased by 11 MPa and 64% relative to pure epoxy resin. Moreover, compared with sample AF/EP, the incorporation of EHP improved both the burning behavior and mechanical properties of the composite, reflecting as reduced burning intensity, increased tensile strength and interlaminar shear strength. The flame-retardant actions, involving flame inhibition and charring and barrier effects, were evaluated quantitatively. Meanwhile, the strengthening and toughening effect benefitted from good compatibility and increased interface bonding.
2024-03-20T09:33:43ZYang, YunxianZhang, QiHao, YiwenLan, XukeHaurie Ibarra, LaiaZheng, DezhiHuang, GuangyanThe mismatch of flame retardancy and mechanical properties is still a challenge for developing high-performance epoxy resin (EP) and its aramid fiber (AF) composite. In this study, a multifunctional cyclotriphosphazene microsphere EHP modified by a phosphaphenanthrene structure was prepared to solve the issue by taking advantage of multiple flame-retardant actions and interfacial interaction. After introducing EHP into epoxy resin, the thermoset exhibited good thermal stability, excellent flame retardancy and enhanced mechanical properties. Especially for sample EP/3%EHP with only 0.39 wt% P-loading, the limiting oxygen index (LOI) value increased from 25.5% to 33.5% accompanied by the V-0 rating in the UL-94 test; besides, the heat release and smoke release behaviors were also inhibited. Additionally, the tensile and impact strengths of the same epoxy sample increased by 11 MPa and 64% relative to pure epoxy resin. Moreover, compared with sample AF/EP, the incorporation of EHP improved both the burning behavior and mechanical properties of the composite, reflecting as reduced burning intensity, increased tensile strength and interlaminar shear strength. The flame-retardant actions, involving flame inhibition and charring and barrier effects, were evaluated quantitatively. Meanwhile, the strengthening and toughening effect benefitted from good compatibility and increased interface bonding.Physical-chemical, mechanical and durability characterization of historical adobe buildings from the State of Michoacan, MexicoSanchez Calvillo, AdriàAlonso Guzman, Elia M.Navarro Ezquerra, AntoniaRuiz Mendoza, MelissaMartinez Molina, WilfridoÁlvarez Galindo, José IgnacioRincón Villarreal, Lídiahttp://hdl.handle.net/2117/4020862024-03-05T14:05:51Z2024-02-16T10:13:06ZPhysical-chemical, mechanical and durability characterization of historical adobe buildings from the State of Michoacan, Mexico
Sanchez Calvillo, Adrià; Alonso Guzman, Elia M.; Navarro Ezquerra, Antonia; Ruiz Mendoza, Melissa; Martinez Molina, Wilfrido; Álvarez Galindo, José Ignacio; Rincón Villarreal, Lídia
Most earthen historical buildings have been abandoned for decades, exposed to the weathering and the passage of time. In Mexico, the low status of earthen constructions has increased these deterioration processes, resulting into the risk of disappearance of this significant architectural heritage. Historical adobes from monumental buildings in the State of Michoacan were sampled and collected in the localities of La Huacana (H) and Santa Cruz de Morelos (SC). The specimens were characterized in the materials laboratory, assessing their physical-chemical, mechanical and durability properties. An interdisciplinary methodology was designed through institutional cooperation and the application of different test methods.
The adobes showed totally different compositions and proportions, and stabilizers like vegetal fibers, nevertheless, the mechanical performance of both samples was very similar, achieving respectable values in the context of historical adobe structures. Several correlations were found through the analyses: the physical properties like the density, the color or the electrical resistivity were related with the mechanical and durability ones; the non-destructive testing (NDT) allowed to calculate the dynamic elasticity modulus and infer the mechanical behavior; the chemical characterization enabled to obtain the elemental and mineralogical composition; and the Atterberg limits gave the soil classification.
The research showed the broad diversity of earthen solutions and demonstrated how the granulometry is not a limitation to the adobe production, since the local soils can achieve similar mechanical and durability behaviors. Furthermore, H presented very different composition than the guidelines for earthen construction; nevertheless, the samples showed better durability performance and lower capillarity absorption rates. It is hoped that the results obtained with this research can help the further development of the earthen materials characterization and the decision-making process for the restoration and conservation of historical and vernacular constructions.
2024-02-16T10:13:06ZSanchez Calvillo, AdriàAlonso Guzman, Elia M.Navarro Ezquerra, AntoniaRuiz Mendoza, MelissaMartinez Molina, WilfridoÁlvarez Galindo, José IgnacioRincón Villarreal, LídiaMost earthen historical buildings have been abandoned for decades, exposed to the weathering and the passage of time. In Mexico, the low status of earthen constructions has increased these deterioration processes, resulting into the risk of disappearance of this significant architectural heritage. Historical adobes from monumental buildings in the State of Michoacan were sampled and collected in the localities of La Huacana (H) and Santa Cruz de Morelos (SC). The specimens were characterized in the materials laboratory, assessing their physical-chemical, mechanical and durability properties. An interdisciplinary methodology was designed through institutional cooperation and the application of different test methods.
The adobes showed totally different compositions and proportions, and stabilizers like vegetal fibers, nevertheless, the mechanical performance of both samples was very similar, achieving respectable values in the context of historical adobe structures. Several correlations were found through the analyses: the physical properties like the density, the color or the electrical resistivity were related with the mechanical and durability ones; the non-destructive testing (NDT) allowed to calculate the dynamic elasticity modulus and infer the mechanical behavior; the chemical characterization enabled to obtain the elemental and mineralogical composition; and the Atterberg limits gave the soil classification.
The research showed the broad diversity of earthen solutions and demonstrated how the granulometry is not a limitation to the adobe production, since the local soils can achieve similar mechanical and durability behaviors. Furthermore, H presented very different composition than the guidelines for earthen construction; nevertheless, the samples showed better durability performance and lower capillarity absorption rates. It is hoped that the results obtained with this research can help the further development of the earthen materials characterization and the decision-making process for the restoration and conservation of historical and vernacular constructions.Bóvedas tabicadasDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, Marianahttp://hdl.handle.net/2117/4016442024-02-09T14:10:14Z2024-02-09T14:03:16ZBóvedas tabicadas
Domènech Rodríguez, Marta; López López, David; Palumbo Fernández, Mariana
2024-02-09T14:03:16ZDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, MarianaBrick TopiaDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, Marianahttp://hdl.handle.net/2117/4016372024-03-07T14:29:05Z2024-02-09T13:30:52ZBrick Topia
Domènech Rodríguez, Marta; López López, David; Palumbo Fernández, Mariana
2024-02-09T13:30:52ZDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, MarianaBrick-topiaDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, Marianahttp://hdl.handle.net/2117/4015312024-02-08T17:50:18Z2024-02-08T17:45:32ZBrick-topia
Domènech Rodríguez, Marta; López López, David; Palumbo Fernández, Mariana
2024-02-08T17:45:32ZDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, MarianaBrick-topiaDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, Marianahttp://hdl.handle.net/2117/4015202024-02-08T16:50:21Z2024-02-08T16:48:03ZBrick-topia
Domènech Rodríguez, Marta; López López, David; Palumbo Fernández, Mariana
2024-02-08T16:48:03ZDomènech Rodríguez, MartaLópez López, DavidPalumbo Fernández, MarianaMechanical properties and durability of biobased fabric-reinforced lime composites intended for strengthening historical masonry structuresRakhsh Mahpour, AliArdanuy Raso, MònicaVentura Casellas, HeuraRosell Amigó, Juan RamónClaramunt Blanes, Josephttp://hdl.handle.net/2117/3999252024-01-28T06:28:46Z2024-01-22T10:20:34ZMechanical properties and durability of biobased fabric-reinforced lime composites intended for strengthening historical masonry structures
Rakhsh Mahpour, Ali; Ardanuy Raso, Mònica; Ventura Casellas, Heura; Rosell Amigó, Juan Ramón; Claramunt Blanes, Josep
The use of lime-based composites reinforced with fabrics made of natural fibers, is a promising solution for the strengthening of historical masonry structures owing to its moderate mechanical strength, similar color and chemical compatibility, avoiding damage on the historical structure and contributing to crack-width control. In this study, a new lime-based composite reinforced with flax nonwoven fabrics is mechanically characterized to study its reinforcement potential in terms of strength, and stress distribution. To this end, laminate plates with lime/metakaolin matrix and four to six layers of fabric reinforcement were produced and totally carbonated in a CO2 chamber. Both the mechanical (flexural and tensile) and durability (against wet-dry cycles) properties of the composite were subsequently assessed. Furthermore, Digital Image Correlation (DIC) was carried out on tensile testing to study the stress distribution. The 6-layer composites displayed the best performance (with flexural and tensile strengths of approximately 5.3 MPa and 2.5 MPa, respectively), followed by the 5-layer and the 4-layer composites. The DIC analysis revealed a higher stress distribution in the 6-layer composites, with an increased number of cracks, although having a lower severity. As for durability, a decrease of 30–45% is observed in flexural strength, and of 6–18% in tensile strength, depending on the number of reinforcing layers. SEM analysis refers to fiber/matrix debonding as the cause of this decrease. No damage has been observed on the fiber surface, which retains its reinforcing capacity. All of the composites displayed strain-hardening behavior in both the unaged and aged conditions. Study outcomes are intended to serve as the basis for the creation of a future, compatible, reliable, and sustainable system given its potential application in the historical restoration of masonry structures
2024-01-22T10:20:34ZRakhsh Mahpour, AliArdanuy Raso, MònicaVentura Casellas, HeuraRosell Amigó, Juan RamónClaramunt Blanes, JosepThe use of lime-based composites reinforced with fabrics made of natural fibers, is a promising solution for the strengthening of historical masonry structures owing to its moderate mechanical strength, similar color and chemical compatibility, avoiding damage on the historical structure and contributing to crack-width control. In this study, a new lime-based composite reinforced with flax nonwoven fabrics is mechanically characterized to study its reinforcement potential in terms of strength, and stress distribution. To this end, laminate plates with lime/metakaolin matrix and four to six layers of fabric reinforcement were produced and totally carbonated in a CO2 chamber. Both the mechanical (flexural and tensile) and durability (against wet-dry cycles) properties of the composite were subsequently assessed. Furthermore, Digital Image Correlation (DIC) was carried out on tensile testing to study the stress distribution. The 6-layer composites displayed the best performance (with flexural and tensile strengths of approximately 5.3 MPa and 2.5 MPa, respectively), followed by the 5-layer and the 4-layer composites. The DIC analysis revealed a higher stress distribution in the 6-layer composites, with an increased number of cracks, although having a lower severity. As for durability, a decrease of 30–45% is observed in flexural strength, and of 6–18% in tensile strength, depending on the number of reinforcing layers. SEM analysis refers to fiber/matrix debonding as the cause of this decrease. No damage has been observed on the fiber surface, which retains its reinforcing capacity. All of the composites displayed strain-hardening behavior in both the unaged and aged conditions. Study outcomes are intended to serve as the basis for the creation of a future, compatible, reliable, and sustainable system given its potential application in the historical restoration of masonry structuresRecovery of mixtures of construction waste, PET and sugarcane bagasse for the manufacture of partition blocksRojas Valencia, María NeftalíRivas Torres, Blanca I.Fernández-Rojas, Denise YeazulGómez Soberón, José Manuel Vicentehttp://hdl.handle.net/2117/3996032024-01-21T19:35:29Z2024-01-16T11:59:39ZRecovery of mixtures of construction waste, PET and sugarcane bagasse for the manufacture of partition blocks
Rojas Valencia, María Neftalí; Rivas Torres, Blanca I.; Fernández-Rojas, Denise Yeazul; Gómez Soberón, José Manuel Vicente
The building industry generates millions of tons of construction and demolition waste annually (12 million tons/year are generated in Mexico, of which only 4% is reused or recycled). Concomitantly, the demand for goods and services by the building industry causes significant environmental impacts. On the other hand, plastic waste is also difficult to assimilate into the environment in the short term, and its recovery is of special interest. Therefore, this research focuses on the feasibility of the manufacture of Partition Blocks (essential building element) through the combination of construction and demolition waste (CDW), polyethylene terephthalate (PET) plastic flakes, dust from tire shredding, and residue from the sugar industry (bagasse). The results of this study show that the Partition Blocks made with CDW and PET reach an average compressive strength of 115.003 kgf/cm2 (11.278 MPa) (suitable for structural use according to Mexican regulations); the use of lime enhances the consistency of the mixture of CDW and PET (increases its cohesion and homogeneity); and finally, these Partition Blocks have a cost comparable to the current conventional Partition Blocks made with virgin material, thus, conferring them validity as a feasible recycling option for these residues.
2024-01-16T11:59:39ZRojas Valencia, María NeftalíRivas Torres, Blanca I.Fernández-Rojas, Denise YeazulGómez Soberón, José Manuel VicenteThe building industry generates millions of tons of construction and demolition waste annually (12 million tons/year are generated in Mexico, of which only 4% is reused or recycled). Concomitantly, the demand for goods and services by the building industry causes significant environmental impacts. On the other hand, plastic waste is also difficult to assimilate into the environment in the short term, and its recovery is of special interest. Therefore, this research focuses on the feasibility of the manufacture of Partition Blocks (essential building element) through the combination of construction and demolition waste (CDW), polyethylene terephthalate (PET) plastic flakes, dust from tire shredding, and residue from the sugar industry (bagasse). The results of this study show that the Partition Blocks made with CDW and PET reach an average compressive strength of 115.003 kgf/cm2 (11.278 MPa) (suitable for structural use according to Mexican regulations); the use of lime enhances the consistency of the mixture of CDW and PET (increases its cohesion and homogeneity); and finally, these Partition Blocks have a cost comparable to the current conventional Partition Blocks made with virgin material, thus, conferring them validity as a feasible recycling option for these residues.Ammonium N-(pyridin-2-ylmethyl)oxamate (AmPicOxam): a novel precursor of calcium oxalate coating for carbonate stone substratesPintus, AnnaAragoni, M. CarlaCarcangiu, GianfrancoCaria, VeronicaColes, SimonDodd, EleanorGiacopetti, LauraGimeno Torrente, DomingoLippolis, VitoMeloni, PaolaMurgia, SimoneNavarro Ezquerra, AntoniaPodda, EnricoUrru, ClaudiaArca, Massimilianohttp://hdl.handle.net/2117/3949132023-10-15T23:04:40Z2023-10-13T10:46:46ZAmmonium N-(pyridin-2-ylmethyl)oxamate (AmPicOxam): a novel precursor of calcium oxalate coating for carbonate stone substrates
Pintus, Anna; Aragoni, M. Carla; Carcangiu, Gianfranco; Caria, Veronica; Coles, Simon; Dodd, Eleanor; Giacopetti, Laura; Gimeno Torrente, Domingo; Lippolis, Vito; Meloni, Paola; Murgia, Simone; Navarro Ezquerra, Antonia; Podda, Enrico; Urru, Claudia; Arca, Massimiliano
Ammonium N-(pyridin-2-ylmethyl)oxamate (AmPicOxam), synthesized from O-methyl-N-(pyridin-2-ylmethyl)oxamate, was spectroscopically and structurally characterized and assayed as a novel precursor for the protection and consolidation of carbonate stone substrates. An in-depth characterization of treated and untreated biomicritic limestone and white Carrara marble samples was carried out by means of SEM microscopy, X-ray powder diffraction, helium pycnometry, determination of water transport properties, and pull-off tests. The improved solubility (1.00 M, 16.5% w/w) of the title compound with respect to ammonium oxalate (0.4 M, 5% w/w) results in the formation of a thicker protective coating of calcium oxalate (CaOx) dihydrate (weddellite) on marble and biomicrite samples after the treatment with 5% and 12% w/w water solutions, producing a reduction in the stone porosity and increased cohesion. Theoretical calculations were carried out at the DFT level to investigate both the electronic structure of the N-(pyridin-2-ylmethyl)oxamate anion and the hydrolysis reaction leading from AmPicOxam to CaOx.
2023-10-13T10:46:46ZPintus, AnnaAragoni, M. CarlaCarcangiu, GianfrancoCaria, VeronicaColes, SimonDodd, EleanorGiacopetti, LauraGimeno Torrente, DomingoLippolis, VitoMeloni, PaolaMurgia, SimoneNavarro Ezquerra, AntoniaPodda, EnricoUrru, ClaudiaArca, MassimilianoAmmonium N-(pyridin-2-ylmethyl)oxamate (AmPicOxam), synthesized from O-methyl-N-(pyridin-2-ylmethyl)oxamate, was spectroscopically and structurally characterized and assayed as a novel precursor for the protection and consolidation of carbonate stone substrates. An in-depth characterization of treated and untreated biomicritic limestone and white Carrara marble samples was carried out by means of SEM microscopy, X-ray powder diffraction, helium pycnometry, determination of water transport properties, and pull-off tests. The improved solubility (1.00 M, 16.5% w/w) of the title compound with respect to ammonium oxalate (0.4 M, 5% w/w) results in the formation of a thicker protective coating of calcium oxalate (CaOx) dihydrate (weddellite) on marble and biomicrite samples after the treatment with 5% and 12% w/w water solutions, producing a reduction in the stone porosity and increased cohesion. Theoretical calculations were carried out at the DFT level to investigate both the electronic structure of the N-(pyridin-2-ylmethyl)oxamate anion and the hydrolysis reaction leading from AmPicOxam to CaOx.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 materialAza-Medina, Leyda CinthiaPalumbo Fernández, MarianaLacasta Palacio, Ana MaríaGonzález Lezcano, Roberto Alonsohttp://hdl.handle.net/2117/3948002023-10-15T23:04:32Z2023-10-11T04:44:19ZCharacterization 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
Aza-Medina, Leyda Cinthia; Palumbo Fernández, Mariana; Lacasta Palacio, Ana María; González Lezcano, Roberto Alonso
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.
2023-10-11T04:44:19ZAza-Medina, Leyda CinthiaPalumbo Fernández, MarianaLacasta Palacio, Ana MaríaGonzález Lezcano, Roberto AlonsoThe 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.