The Experts below are selected from a list of 1992 Experts worldwide ranked by ideXlab platform
Maria C. G. Juenger - One of the best experts on this subject based on the ideXlab platform.
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Effect of calcination on the Reactivity of natural clinoptilolite zeolites used as supplementary cementitious materials
Construction and Building Materials, 2020Co-Authors: Lisa E. Burris, Maria C. G. JuengerAbstract:Abstract This study examined several sources of natural clinoptilolite zeolite calcined at temperatures of 300 °C-965 °C, tracking changes in phase content, particle size, surface area, and pore size distribution. Changes in Pozzolanic Reactivity with calcination were measured through calcium hydroxide content of hydrated zeolite-cement pastes and compressive strengths of cement mortars. Calcination increased zeolite particle size and reduced porosity and surface area, resulting in decreased zeolite Pozzolanic Reactivity despite increased amorphous content in the samples. Overall, in contrast to what has been shown previously in literature, calcination was ineffective in increasing the Reactivity of clinoptilolite zeolites for use as SCMs.
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The effect of acid treatment on the Reactivity of natural zeolites used as supplementary cementitious materials
Cement and Concrete Research, 2016Co-Authors: Lisa E. Burris, Maria C. G. JuengerAbstract:This work investigated the use of acid treatment as a method for increasing the Reactivity of natural zeolite used as a supplementary cementitious material. The effects of treating a natural clinoptilolite zeolite with nine acid solutions, 0.1 M, 0.5 M, or 1 M hydrochloric or nitric acid or 0.1 M, 0.5 M, or 0.87 M acetic acid, were measured using x-ray diffraction, particle size analysis, pore size distribution and surface area analysis. The zeolite Pozzolanic Reactivity was determined by measuring the quantity of portlandite in hydrated zeolite-cement paste after 28 and 90 days. Results showed that acid treatment increased zeolite surface area, resulting in increased zeolite Pozzolanic Reactivity, independent of the solution concentration used. Cement hydration was also increased, evidenced by greater rates of heat evolution from cement-zeolite pastes. Additionally, although reductions of portlandite occurred most quickly in pastes with zeolites treated with strong acids, by 90 days the zeolites treated with acetic acid solutions showed comparable portlandite reductions.
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The effect of zinc oxide additions on the performance of calcined sodium montmorillonite and illite shale supplementary cementitious materials
Cement and Concrete Composites, 2014Co-Authors: Sarah C. Taylor-lange, Kyle A Riding, Fahad Rajabali, Natalie A. Holsomback, Maria C. G. JuengerAbstract:Abstract The objectives of this study were to use activation treatments on sodium montmorillonite and illite shale, to alter early hydration or later Pozzolanic Reactivity when used as supplementary cementitious materials (SCMs). For comparison purposes, treatment methods were also applied to the highly reactive pozzolan, metakaolin, and the inert filler, quartz. Activation treatment strategies included the addition of 0.15 wt% zinc oxide and the use of thermal treatments to the SCMs at temperatures of 650 °C, 830 °C and 930 °C. The use of zinc oxide additions increased the early hydration rate of SCM-containing pastes, yet introduced a chemical retardation and negatively impacted early compressive strengths. Moreover, the results suggest that retardation was inversely correlated with the Pozzolanic Reactivity of the SCM used. Thermal treatment methods were effective at influencing the SCM Pozzolanic Reactivity, with montmorillonite calcined at 830 °C and illite calcined at 930 °C behaving as late-reacting pozzolans. SCMs calcined at these temperatures resulted in higher 90 day compressive strengths compared to mortars containing the quartz filler. Overall, this study provides insight into different strategies that maybe used to enhance the Reactivity of impure calcined clays in order to facilitate their acceptance into the concrete industry.
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Increasing the Reactivity of metakaolin-cement blends using zinc oxide
Cement & Concrete Composites, 2012Co-Authors: Sarah C. Taylor-lange, Kyle A Riding, Maria C. G. JuengerAbstract:Abstract This study aimed to improve the Reactivity of metakaolin-cement mixtures using ZnO additions. Kaolinite samples with 0.1–1 wt% ZnO were calcined at temperature intervals of 50 °C from 500 to 650 °C for 1 h. The resulting metakaolins were examined for structural changes after calcination and for their Pozzolanic Reactivity, influence on the hydration behavior of cement pastes, and impact on the compressive strength of mortar cubes. ZnO behaved as a delayed accelerator for cement paste. However, when ZnO was combined with highly amorphous metakaolin, chemical retardation was eliminated while acceleration was maintained. Such systems also had increased 28-day compressive strengths. ZnO additions did not affect the degree of dehydroxylation or the Pozzolanic Reactivity of the metakaolin. These results could facilitate the use of less pure calcined clays as SCM by providing a mechanism for improving Reactivity and may also impact the ability to use zinc-contaminated materials in concrete.
Jordi Payá - One of the best experts on this subject based on the ideXlab platform.
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Comparison of original and washed pure sugar cane bagasse ashes as supplementary cementing materials
Construction and Building Materials, 2021Co-Authors: Gabriela Pitolli Lyra, Lourdes Soriano, María Victoria Borrachero, Jordi Payá, João Adriano RossignoloAbstract:Abstract The objective of this study was to evaluate the effects of potassium extraction on the Pozzolanicity of sugar cane bagasse ash (SCBA), with the aim of producing reactive ash for use in cementitious composites. The sugar cane bagasse ashes were produced at 600 °C for 60 min, with a heating rate of 4 °C/min. The ashes were then ground and washed for potassium extraction. In order to assess the ash behaviour before and after potassium extraction, the following procedures were performed: energy-dispersive spectroscopy (EDS), loss on ignition (LOI), particle size distribution, x-ray powder diffraction (XRD), x-ray diffraction in calcium hydroxide paste, analysis of lime fixation by thermogravimetry, and evaluation of Pozzolanic Reactivity analyses. Results show that the extraction of potassium, increases the concentration of silica causing a greater Pozzolanic Reactivity of the ashes.
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Influence of microwave oven calcination on the Pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry
Construction and Building Materials, 2018Co-Authors: João Adriano Rossignolo, Lourdes Soriano, María Victoria Borrachero, Jordi PayáAbstract:Abstract This study evaluates the effects of microwave oven calcining conditions on the Pozzolanicity of sugar cane bagasse ashes (SCBA) generated by the electric power cogeneration industry. The calcining temperatures varied between 600 °C and 800 °C, and the permanence times were 60 min in an electric oven and 30, 45 and 60 min in a microwave oven. To evaluate the behaviour of the ashes according to different calcining conditions, we carried out the following analyses: granulometric distribution (laser diffraction), oxide percentages (XRF), loss on ignition (LOI), powder X-ray diffraction (XRD), Pozzolanic Reactivity, determination of amorphous silica content and thermogravimetry of hydrated lime pastes (DTG). The results show that SCBA calcination in a microwave oven results in ashes with greater Pozzolanic Reactivity and a significantly more efficient burning process than in an electric oven.
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Pozzolanic Reactivity Studies on a Biomass-Derived Waste from Sugar Cane Production: Sugar Cane Straw Ash (SCSA)
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: J.c.b. Moraes, José Luiz Pinheiro Melges, Jorge Luís Akasaki, Mauro Mitsuuchi Tashima, Lourdes Soriano, José Monzó, María Victoria Borrachero, Jordi PayáAbstract:Biomass has gained in importance as an energy source in recent years. One of the crops that presents interesting opportunities with regard to biomass is sugar cane. In Brazil, sugar cane production is increasing for alcohol and sugar manufacture. Some byproducts, such as sugar cane straw, also are obtained during harvesting. Because of the calorific value of the sugar cane straw, its use as biomass is increasing. After the straw is burned to produce energy, an ash is obtained: sugar cane straw ash (SCSA). This waste needs an appropriate destination, and since the recent publication of successful studies using biomass derived-ashes as Pozzolanic material, the present study aimed to assess the Pozzolanic Reactivity of sugar cane straw ash. The Pozzolanic activity was assessed using a new and simple recently proposed method: evaluation of the electrical conductivity of calcium hydroxide (CH) and pozzolan suspensions, in which solid CH is initially present. These results were compared to those of two other we...
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Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland
Materiales de Construcción, 2009Co-Authors: Jordi Payá, María Victoria Borrachero, José Monzó, Lourdes SorianoAbstract:The fluidized-bed catalytic cracking catalyst (FCC) it is a residue from the industry of the petroleum that shows a high Pozzolanic Reactivity and, in cementing matrix, it significantly improves their mechanical behaviour as well as durability. In this research a comparative study on residues of catalyst from different sources has been carried out, in order to know if these residues can be used jointly in an indiscriminate way or, on the contrary, it is necessary to classify them according to their characteristics. Thus, a study on five different FCC residues, supplied from different companies, has been carried out, and their physical-chemical characteristics, Pozzolanic Reactivity by means of thermogravimetric analysis and the evolution of the mechanical strength of mortars were studied. After analyzing all the aspects, it can be concluded that no significant differences among the different tested catalysts were found.
João Adriano Rossignolo - One of the best experts on this subject based on the ideXlab platform.
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Comparison of original and washed pure sugar cane bagasse ashes as supplementary cementing materials
Construction and Building Materials, 2021Co-Authors: Gabriela Pitolli Lyra, Lourdes Soriano, María Victoria Borrachero, Jordi Payá, João Adriano RossignoloAbstract:Abstract The objective of this study was to evaluate the effects of potassium extraction on the Pozzolanicity of sugar cane bagasse ash (SCBA), with the aim of producing reactive ash for use in cementitious composites. The sugar cane bagasse ashes were produced at 600 °C for 60 min, with a heating rate of 4 °C/min. The ashes were then ground and washed for potassium extraction. In order to assess the ash behaviour before and after potassium extraction, the following procedures were performed: energy-dispersive spectroscopy (EDS), loss on ignition (LOI), particle size distribution, x-ray powder diffraction (XRD), x-ray diffraction in calcium hydroxide paste, analysis of lime fixation by thermogravimetry, and evaluation of Pozzolanic Reactivity analyses. Results show that the extraction of potassium, increases the concentration of silica causing a greater Pozzolanic Reactivity of the ashes.
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Influence of microwave oven calcination on the Pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry
Construction and Building Materials, 2018Co-Authors: João Adriano Rossignolo, Lourdes Soriano, María Victoria Borrachero, Jordi PayáAbstract:Abstract This study evaluates the effects of microwave oven calcining conditions on the Pozzolanicity of sugar cane bagasse ashes (SCBA) generated by the electric power cogeneration industry. The calcining temperatures varied between 600 °C and 800 °C, and the permanence times were 60 min in an electric oven and 30, 45 and 60 min in a microwave oven. To evaluate the behaviour of the ashes according to different calcining conditions, we carried out the following analyses: granulometric distribution (laser diffraction), oxide percentages (XRF), loss on ignition (LOI), powder X-ray diffraction (XRD), Pozzolanic Reactivity, determination of amorphous silica content and thermogravimetry of hydrated lime pastes (DTG). The results show that SCBA calcination in a microwave oven results in ashes with greater Pozzolanic Reactivity and a significantly more efficient burning process than in an electric oven.
María Victoria Borrachero - One of the best experts on this subject based on the ideXlab platform.
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Comparison of original and washed pure sugar cane bagasse ashes as supplementary cementing materials
Construction and Building Materials, 2021Co-Authors: Gabriela Pitolli Lyra, Lourdes Soriano, María Victoria Borrachero, Jordi Payá, João Adriano RossignoloAbstract:Abstract The objective of this study was to evaluate the effects of potassium extraction on the Pozzolanicity of sugar cane bagasse ash (SCBA), with the aim of producing reactive ash for use in cementitious composites. The sugar cane bagasse ashes were produced at 600 °C for 60 min, with a heating rate of 4 °C/min. The ashes were then ground and washed for potassium extraction. In order to assess the ash behaviour before and after potassium extraction, the following procedures were performed: energy-dispersive spectroscopy (EDS), loss on ignition (LOI), particle size distribution, x-ray powder diffraction (XRD), x-ray diffraction in calcium hydroxide paste, analysis of lime fixation by thermogravimetry, and evaluation of Pozzolanic Reactivity analyses. Results show that the extraction of potassium, increases the concentration of silica causing a greater Pozzolanic Reactivity of the ashes.
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Influence of microwave oven calcination on the Pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry
Construction and Building Materials, 2018Co-Authors: João Adriano Rossignolo, Lourdes Soriano, María Victoria Borrachero, Jordi PayáAbstract:Abstract This study evaluates the effects of microwave oven calcining conditions on the Pozzolanicity of sugar cane bagasse ashes (SCBA) generated by the electric power cogeneration industry. The calcining temperatures varied between 600 °C and 800 °C, and the permanence times were 60 min in an electric oven and 30, 45 and 60 min in a microwave oven. To evaluate the behaviour of the ashes according to different calcining conditions, we carried out the following analyses: granulometric distribution (laser diffraction), oxide percentages (XRF), loss on ignition (LOI), powder X-ray diffraction (XRD), Pozzolanic Reactivity, determination of amorphous silica content and thermogravimetry of hydrated lime pastes (DTG). The results show that SCBA calcination in a microwave oven results in ashes with greater Pozzolanic Reactivity and a significantly more efficient burning process than in an electric oven.
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Pozzolanic Reactivity Studies on a Biomass-Derived Waste from Sugar Cane Production: Sugar Cane Straw Ash (SCSA)
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: J.c.b. Moraes, José Luiz Pinheiro Melges, Jorge Luís Akasaki, Mauro Mitsuuchi Tashima, Lourdes Soriano, José Monzó, María Victoria Borrachero, Jordi PayáAbstract:Biomass has gained in importance as an energy source in recent years. One of the crops that presents interesting opportunities with regard to biomass is sugar cane. In Brazil, sugar cane production is increasing for alcohol and sugar manufacture. Some byproducts, such as sugar cane straw, also are obtained during harvesting. Because of the calorific value of the sugar cane straw, its use as biomass is increasing. After the straw is burned to produce energy, an ash is obtained: sugar cane straw ash (SCSA). This waste needs an appropriate destination, and since the recent publication of successful studies using biomass derived-ashes as Pozzolanic material, the present study aimed to assess the Pozzolanic Reactivity of sugar cane straw ash. The Pozzolanic activity was assessed using a new and simple recently proposed method: evaluation of the electrical conductivity of calcium hydroxide (CH) and pozzolan suspensions, in which solid CH is initially present. These results were compared to those of two other we...
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Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland
Materiales de Construcción, 2009Co-Authors: Jordi Payá, María Victoria Borrachero, José Monzó, Lourdes SorianoAbstract:The fluidized-bed catalytic cracking catalyst (FCC) it is a residue from the industry of the petroleum that shows a high Pozzolanic Reactivity and, in cementing matrix, it significantly improves their mechanical behaviour as well as durability. In this research a comparative study on residues of catalyst from different sources has been carried out, in order to know if these residues can be used jointly in an indiscriminate way or, on the contrary, it is necessary to classify them according to their characteristics. Thus, a study on five different FCC residues, supplied from different companies, has been carried out, and their physical-chemical characteristics, Pozzolanic Reactivity by means of thermogravimetric analysis and the evolution of the mechanical strength of mortars were studied. After analyzing all the aspects, it can be concluded that no significant differences among the different tested catalysts were found.
Lourdes Soriano - One of the best experts on this subject based on the ideXlab platform.
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Comparison of original and washed pure sugar cane bagasse ashes as supplementary cementing materials
Construction and Building Materials, 2021Co-Authors: Gabriela Pitolli Lyra, Lourdes Soriano, María Victoria Borrachero, Jordi Payá, João Adriano RossignoloAbstract:Abstract The objective of this study was to evaluate the effects of potassium extraction on the Pozzolanicity of sugar cane bagasse ash (SCBA), with the aim of producing reactive ash for use in cementitious composites. The sugar cane bagasse ashes were produced at 600 °C for 60 min, with a heating rate of 4 °C/min. The ashes were then ground and washed for potassium extraction. In order to assess the ash behaviour before and after potassium extraction, the following procedures were performed: energy-dispersive spectroscopy (EDS), loss on ignition (LOI), particle size distribution, x-ray powder diffraction (XRD), x-ray diffraction in calcium hydroxide paste, analysis of lime fixation by thermogravimetry, and evaluation of Pozzolanic Reactivity analyses. Results show that the extraction of potassium, increases the concentration of silica causing a greater Pozzolanic Reactivity of the ashes.
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Influence of microwave oven calcination on the Pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry
Construction and Building Materials, 2018Co-Authors: João Adriano Rossignolo, Lourdes Soriano, María Victoria Borrachero, Jordi PayáAbstract:Abstract This study evaluates the effects of microwave oven calcining conditions on the Pozzolanicity of sugar cane bagasse ashes (SCBA) generated by the electric power cogeneration industry. The calcining temperatures varied between 600 °C and 800 °C, and the permanence times were 60 min in an electric oven and 30, 45 and 60 min in a microwave oven. To evaluate the behaviour of the ashes according to different calcining conditions, we carried out the following analyses: granulometric distribution (laser diffraction), oxide percentages (XRF), loss on ignition (LOI), powder X-ray diffraction (XRD), Pozzolanic Reactivity, determination of amorphous silica content and thermogravimetry of hydrated lime pastes (DTG). The results show that SCBA calcination in a microwave oven results in ashes with greater Pozzolanic Reactivity and a significantly more efficient burning process than in an electric oven.
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Pozzolanic Reactivity Studies on a Biomass-Derived Waste from Sugar Cane Production: Sugar Cane Straw Ash (SCSA)
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: J.c.b. Moraes, José Luiz Pinheiro Melges, Jorge Luís Akasaki, Mauro Mitsuuchi Tashima, Lourdes Soriano, José Monzó, María Victoria Borrachero, Jordi PayáAbstract:Biomass has gained in importance as an energy source in recent years. One of the crops that presents interesting opportunities with regard to biomass is sugar cane. In Brazil, sugar cane production is increasing for alcohol and sugar manufacture. Some byproducts, such as sugar cane straw, also are obtained during harvesting. Because of the calorific value of the sugar cane straw, its use as biomass is increasing. After the straw is burned to produce energy, an ash is obtained: sugar cane straw ash (SCSA). This waste needs an appropriate destination, and since the recent publication of successful studies using biomass derived-ashes as Pozzolanic material, the present study aimed to assess the Pozzolanic Reactivity of sugar cane straw ash. The Pozzolanic activity was assessed using a new and simple recently proposed method: evaluation of the electrical conductivity of calcium hydroxide (CH) and pozzolan suspensions, in which solid CH is initially present. These results were compared to those of two other we...
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Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland
Materiales de Construcción, 2009Co-Authors: Jordi Payá, María Victoria Borrachero, José Monzó, Lourdes SorianoAbstract:The fluidized-bed catalytic cracking catalyst (FCC) it is a residue from the industry of the petroleum that shows a high Pozzolanic Reactivity and, in cementing matrix, it significantly improves their mechanical behaviour as well as durability. In this research a comparative study on residues of catalyst from different sources has been carried out, in order to know if these residues can be used jointly in an indiscriminate way or, on the contrary, it is necessary to classify them according to their characteristics. Thus, a study on five different FCC residues, supplied from different companies, has been carried out, and their physical-chemical characteristics, Pozzolanic Reactivity by means of thermogravimetric analysis and the evolution of the mechanical strength of mortars were studied. After analyzing all the aspects, it can be concluded that no significant differences among the different tested catalysts were found.