Joao Baldo | UFSCar - Federal University of São Carlos (original) (raw)
Papers by Joao Baldo
Editora Científica Digital eBooks, 2021
Physical and mechanical properties of low, ultralow and no cement refractory castables containing... more Physical and mechanical properties of low, ultralow and no cement refractory castables containing MgO nanoparticles developed in situ by means of polymeric resins (Propriedades físicas e mecânicas de concretos refratários de baixo, ultrabaixo e sem cimento contendo nanopartículas de MgO desenvolvidas in situ por meio de resinas poliméricas)
Interceram - International Ceramic Review, 2014
Cerâmica Industrial, 2017
Resumo Neste estudo, pequenas quantidades de quartzo da composição de uma barbotina típica de por... more Resumo Neste estudo, pequenas quantidades de quartzo da composição de uma barbotina típica de porcelana tradicional, foram substituídas por microsílica Elkem 920 D. Quatro diferentes teores foram utilizados de modo a se analisar o efeito das partículas esféricas submicrométricas da microsílica na reologia do sistema. A avaliação foi realizada com viscosímetro Brookfield modelo DV-I Prime. Os resultados indicam que a inclusão de microsílica promoveu uma diminuição expressiva na viscosidade e diferentemente do esperado, a inclusão das partículas esféricas submicrométricas da mesma, levou a um comportamento reopéxico quase dilatante e não pseudoplástico ou tixotrópico. Porém, este desvio reológico, não alterou a capacidade e qualidade de colagem das barbotinas aditivadas com microílica.
Cerâmica, 2014
Neste trabalho são apresentadas algumas propriedades relevantes de argamassas leves para revestim... more Neste trabalho são apresentadas algumas propriedades relevantes de argamassas leves para revestimento confeccionadas com; cimento, areia, cal, vermiculita e agregados de borracha de pneus reciclados. Tais argamassas foram comparativamente avaliadas em relação a outras feitas com os mesmos componentes exceto o agregado de borracha reciclada de pneus. As propriedades avaliadas no estado a fresco foram; consistência, retenção de água, tempo final da pega, teor de água, densidade de massa (teórica, experimental) e teor de ar incorporado. No estado endurecido avaliou-se a densidade de massa aparente, a resistência à compressão e a resistência de aderência sob tração. Comparando-se os resultados dos ensaios no estado fresco e no estado endurecido, pode se concluir que as argamassas contendo vermiculita expandida e borracha reciclada de pneus, apresentaram propriedades similares no estado fresco, enquanto que no estado endurecido apresentaram melhores resultados de resistência à compressão...
Ceramica (Sao Paulo), 1996
Ceramica (Sao Paulo), 1994
Ceramica (Sao Paulo), 1989
International Journal of Civil & Environmental Engineering, 2014
In this work it is presented a simple method for Portland cement concrete dosing procedure. It is... more In this work it is presented a simple method for Portland cement concrete dosing procedure. It is based on particle packing first principles together with a concise way of treating separately the needs for admixture water for each individual concrete constituent (coarse, medium and fine aggregates and the cement), as well as to the void content. The procedure is also supported by a specific mixing sequence of the raw materials. The verification of the model efficiency, was made by comparing the strength development at various ages of concrete specimens produced by means of the new dosing procedure, with that presented by conventional portland cement concrete specified for 35MPa 5,076 psi of compressive strength, using the Brazilian Portland Cement Association (ABCP) method. After 28 days, the new dosing method provided a concrete with average compressive strength value of 54MPa 7,832 psi. Conversely the one produced under ABCP method reached an average compressive strength of 43MPa 6,236 psi at the same age, containing however 30% higher cement content.
International Journal of Civil & Environmental Engineering IJCEE-IJENS, 2014
Abstract-- In this work it is presented a simple method for Portland cement concrete dosing proce... more Abstract-- In this work it is presented a simple method for Portland cement concrete dosing procedure. It is based on particle packing first principles together with a concise way of treating separately the needs for admixture water for each individual concrete constituent (coarse, medium and fine aggregates and the cement), as well as to the void content. The procedure is also supported by a specific mixing sequence of the raw materials. The verification of the model efficiency, was made by comparing the strength development at various ages of concrete specimens produced by means of the new dosing procedure, with that presented by conventional portland cement concrete specified for 35MPa 5,076 psi of compressive strength, using the Brazilian Portland Cement Association (ABCP) method. After 28 days, the new dosing method provided a concrete with average compressive strength value of 54MPa 7,832 psi. Conversely the one produced under ABCP method reached an average compressive strengt...
Academia Letters, 2021
In this work it is shown the feasibility of recycling a fire assay derived slag, as an effective ... more In this work it is shown the feasibility of recycling a fire assay derived slag, as an effective fluxing component in a porcelain like floor tile composition of the BIb class under the ISO-10545-3-1995 standard. The results indicate that additions of 2wt% and 4wt% of the fire assay slag, were enough to confer an expressive decrease of 40˚C to 85˚C in the firing temperature, when compared to that normally required for a commercial BIb mass. Moreover, the slag addition did not alter the mechanical strength and water absorption levels, by keeping these properties within the required limits stablished by the EN ISO 10545-3-1995 BIb standard.
Key Engineering Materials, Jul 11, 2012
Chemical analysis of household waste from the sanitary ware industry is of fundamental importance... more Chemical analysis of household waste from the sanitary ware industry is of fundamental importance in order to detect the presence of AAR (alkali-aggregate reaction), the same in field or laboratory. There are several test methods, these methods can detect pre-reactivity of aggregates compared to the sodium or potassium hydroxide present in hydrated cement paste. For the preparation of both the concrete and the mortar, from the recycled material, the aggregates were reduced until it had texture, close to the river sand and gravel. The analyses stayed in determining the potential of the alkali-aggregate reactivity. Thus the results of chemical and physical characterization of the material, indicated a willingness to be used as aggregate in mortar and concrete, due to the availability of waste, the good properties given and the gains in cost, beyond the environmental management, they promote the viability of the process of recycling of waste. 1
Key Engineering Materials, 2012
Chemical analysis of household waste from the sanitary ware industry is of fundamental importance... more Chemical analysis of household waste from the sanitary ware industry is of fundamental importance in order to detect the presence of AAR (alkali-aggregate reaction), the same in field or laboratory. There are several test methods, these methods can detect pre-reactivity of aggregates compared to the sodium or potassium hydroxide present in hydrated cement paste. For the preparation of both the concrete and the mortar, from the recycled material, the aggregates were reduced until it had texture, close to the river sand and gravel. The analyses stayed in determining the potential of the alkali-aggregate reactivity. Thus the results of chemical and physical characterization of the material, indicated a willingness to be used as aggregate in mortar and concrete, due to the availability of waste, the good properties given and the gains in cost, beyond the environmental management, they promote the viability of the process of recycling of waste. 1
Journal of Applied Polymer Science, 2002
Gregorio, R., Chaud, MR, Nunes Dos Santos, W. and Baldo, JB (2002), Miscibility and morphology of... more Gregorio, R., Chaud, MR, Nunes Dos Santos, W. and Baldo, JB (2002), Miscibility and morphology of poly (vinylidene fluoride)/poly [(vinylidene fluoride)-ran-trifluorethylene] blends. Journal of Applied Polymer Science, 85: 13621369. doi: 10.1002/app. 10529
Journal of Applied Polymer Science, 2002
This study presents an investigation of the effect of the different crystalline phases of each bl... more This study presents an investigation of the effect of the different crystalline phases of each blend component on miscibility when blending poly(vinylidene fluoride) (PVDF) and its copolymer poly[(vinylidene fluoride)-ran-trifluorethylene] [P(VDF–TrFE)] containing 72 mol % of VDF. It was found that, when both components crystallized in their ferroelectric phase, the PVDF showed a strong effect on the crystallinity and phase-transition temperature of the copolymer, indicating partial miscibility in the crystalline state. On the other hand, immiscibility was observed when both components, after melting, were crystallized in their paraelectric phase. In this case, however, a decrease in crystallization temperatures suggested a strong interaction between monomers in the liquid state. Blend morphologies indicated that, in spite of the lack of miscibility in the crystalline state, there is at least miscibility between PVDF and P(VDF–TrFE) in the liquid state, and that a very intimate mixt...
Editora Científica Digital eBooks, 2021
Physical and mechanical properties of low, ultralow and no cement refractory castables containing... more Physical and mechanical properties of low, ultralow and no cement refractory castables containing MgO nanoparticles developed in situ by means of polymeric resins (Propriedades físicas e mecânicas de concretos refratários de baixo, ultrabaixo e sem cimento contendo nanopartículas de MgO desenvolvidas in situ por meio de resinas poliméricas)
Interceram - International Ceramic Review, 2014
Cerâmica Industrial, 2017
Resumo Neste estudo, pequenas quantidades de quartzo da composição de uma barbotina típica de por... more Resumo Neste estudo, pequenas quantidades de quartzo da composição de uma barbotina típica de porcelana tradicional, foram substituídas por microsílica Elkem 920 D. Quatro diferentes teores foram utilizados de modo a se analisar o efeito das partículas esféricas submicrométricas da microsílica na reologia do sistema. A avaliação foi realizada com viscosímetro Brookfield modelo DV-I Prime. Os resultados indicam que a inclusão de microsílica promoveu uma diminuição expressiva na viscosidade e diferentemente do esperado, a inclusão das partículas esféricas submicrométricas da mesma, levou a um comportamento reopéxico quase dilatante e não pseudoplástico ou tixotrópico. Porém, este desvio reológico, não alterou a capacidade e qualidade de colagem das barbotinas aditivadas com microílica.
Cerâmica, 2014
Neste trabalho são apresentadas algumas propriedades relevantes de argamassas leves para revestim... more Neste trabalho são apresentadas algumas propriedades relevantes de argamassas leves para revestimento confeccionadas com; cimento, areia, cal, vermiculita e agregados de borracha de pneus reciclados. Tais argamassas foram comparativamente avaliadas em relação a outras feitas com os mesmos componentes exceto o agregado de borracha reciclada de pneus. As propriedades avaliadas no estado a fresco foram; consistência, retenção de água, tempo final da pega, teor de água, densidade de massa (teórica, experimental) e teor de ar incorporado. No estado endurecido avaliou-se a densidade de massa aparente, a resistência à compressão e a resistência de aderência sob tração. Comparando-se os resultados dos ensaios no estado fresco e no estado endurecido, pode se concluir que as argamassas contendo vermiculita expandida e borracha reciclada de pneus, apresentaram propriedades similares no estado fresco, enquanto que no estado endurecido apresentaram melhores resultados de resistência à compressão...
Ceramica (Sao Paulo), 1996
Ceramica (Sao Paulo), 1994
Ceramica (Sao Paulo), 1989
International Journal of Civil & Environmental Engineering, 2014
In this work it is presented a simple method for Portland cement concrete dosing procedure. It is... more In this work it is presented a simple method for Portland cement concrete dosing procedure. It is based on particle packing first principles together with a concise way of treating separately the needs for admixture water for each individual concrete constituent (coarse, medium and fine aggregates and the cement), as well as to the void content. The procedure is also supported by a specific mixing sequence of the raw materials. The verification of the model efficiency, was made by comparing the strength development at various ages of concrete specimens produced by means of the new dosing procedure, with that presented by conventional portland cement concrete specified for 35MPa 5,076 psi of compressive strength, using the Brazilian Portland Cement Association (ABCP) method. After 28 days, the new dosing method provided a concrete with average compressive strength value of 54MPa 7,832 psi. Conversely the one produced under ABCP method reached an average compressive strength of 43MPa 6,236 psi at the same age, containing however 30% higher cement content.
International Journal of Civil & Environmental Engineering IJCEE-IJENS, 2014
Abstract-- In this work it is presented a simple method for Portland cement concrete dosing proce... more Abstract-- In this work it is presented a simple method for Portland cement concrete dosing procedure. It is based on particle packing first principles together with a concise way of treating separately the needs for admixture water for each individual concrete constituent (coarse, medium and fine aggregates and the cement), as well as to the void content. The procedure is also supported by a specific mixing sequence of the raw materials. The verification of the model efficiency, was made by comparing the strength development at various ages of concrete specimens produced by means of the new dosing procedure, with that presented by conventional portland cement concrete specified for 35MPa 5,076 psi of compressive strength, using the Brazilian Portland Cement Association (ABCP) method. After 28 days, the new dosing method provided a concrete with average compressive strength value of 54MPa 7,832 psi. Conversely the one produced under ABCP method reached an average compressive strengt...
Academia Letters, 2021
In this work it is shown the feasibility of recycling a fire assay derived slag, as an effective ... more In this work it is shown the feasibility of recycling a fire assay derived slag, as an effective fluxing component in a porcelain like floor tile composition of the BIb class under the ISO-10545-3-1995 standard. The results indicate that additions of 2wt% and 4wt% of the fire assay slag, were enough to confer an expressive decrease of 40˚C to 85˚C in the firing temperature, when compared to that normally required for a commercial BIb mass. Moreover, the slag addition did not alter the mechanical strength and water absorption levels, by keeping these properties within the required limits stablished by the EN ISO 10545-3-1995 BIb standard.
Key Engineering Materials, Jul 11, 2012
Chemical analysis of household waste from the sanitary ware industry is of fundamental importance... more Chemical analysis of household waste from the sanitary ware industry is of fundamental importance in order to detect the presence of AAR (alkali-aggregate reaction), the same in field or laboratory. There are several test methods, these methods can detect pre-reactivity of aggregates compared to the sodium or potassium hydroxide present in hydrated cement paste. For the preparation of both the concrete and the mortar, from the recycled material, the aggregates were reduced until it had texture, close to the river sand and gravel. The analyses stayed in determining the potential of the alkali-aggregate reactivity. Thus the results of chemical and physical characterization of the material, indicated a willingness to be used as aggregate in mortar and concrete, due to the availability of waste, the good properties given and the gains in cost, beyond the environmental management, they promote the viability of the process of recycling of waste. 1
Key Engineering Materials, 2012
Chemical analysis of household waste from the sanitary ware industry is of fundamental importance... more Chemical analysis of household waste from the sanitary ware industry is of fundamental importance in order to detect the presence of AAR (alkali-aggregate reaction), the same in field or laboratory. There are several test methods, these methods can detect pre-reactivity of aggregates compared to the sodium or potassium hydroxide present in hydrated cement paste. For the preparation of both the concrete and the mortar, from the recycled material, the aggregates were reduced until it had texture, close to the river sand and gravel. The analyses stayed in determining the potential of the alkali-aggregate reactivity. Thus the results of chemical and physical characterization of the material, indicated a willingness to be used as aggregate in mortar and concrete, due to the availability of waste, the good properties given and the gains in cost, beyond the environmental management, they promote the viability of the process of recycling of waste. 1
Journal of Applied Polymer Science, 2002
Gregorio, R., Chaud, MR, Nunes Dos Santos, W. and Baldo, JB (2002), Miscibility and morphology of... more Gregorio, R., Chaud, MR, Nunes Dos Santos, W. and Baldo, JB (2002), Miscibility and morphology of poly (vinylidene fluoride)/poly [(vinylidene fluoride)-ran-trifluorethylene] blends. Journal of Applied Polymer Science, 85: 13621369. doi: 10.1002/app. 10529
Journal of Applied Polymer Science, 2002
This study presents an investigation of the effect of the different crystalline phases of each bl... more This study presents an investigation of the effect of the different crystalline phases of each blend component on miscibility when blending poly(vinylidene fluoride) (PVDF) and its copolymer poly[(vinylidene fluoride)-ran-trifluorethylene] [P(VDF–TrFE)] containing 72 mol % of VDF. It was found that, when both components crystallized in their ferroelectric phase, the PVDF showed a strong effect on the crystallinity and phase-transition temperature of the copolymer, indicating partial miscibility in the crystalline state. On the other hand, immiscibility was observed when both components, after melting, were crystallized in their paraelectric phase. In this case, however, a decrease in crystallization temperatures suggested a strong interaction between monomers in the liquid state. Blend morphologies indicated that, in spite of the lack of miscibility in the crystalline state, there is at least miscibility between PVDF and P(VDF–TrFE) in the liquid state, and that a very intimate mixt...