International Journal of Molecular Sciences, Jul 31, 2021
Optical Properties of Composites Based on Poly (o-phenylenediamine), Poly (Vinylenefluoride) and ... more Optical Properties of Composites Based on Poly (o-phenylenediamine), Poly (Vinylenefluoride) and Double-Wall Carbon Nanotubes. Int.
The effect of the addition of small amounts of meat and bone meal (MBM) ash on the clinkering pro... more The effect of the addition of small amounts of meat and bone meal (MBM) ash on the clinkering process and on the hydraulic reactivity of obtained clinkers was studied. The study was aimed at simulating the clinker burning process in an industrial furnace that replaced up to 20 wt% conventional fuel with MBM used as alternative fuel. Laboratory clinkers were obtained by adding from 0.07 to 0.88 wt.% of MBM ash to an industrial raw mixture, and were compared with a clinker obtained without additions. The free lime content in the clinker increased steadily when the concentration of phosphorus was increased up to a level of 0.16 wt% P2O5 in the raw mixture. With higher phosphorus additions the free lime content increased only insignificantly. The results of X-ray microanalysis indicated that a maximum of 2.3 and 3.3% of the silicon sites were replaced by phosphorus in alite and belite, respectively. The clinker containing 0.6 wt% P2O5 slowed down the hydration process for approximately 1 day and thereafter began to exceed the degree of hydration of the reference sample. The values of degree of hydration of clinker rich in P2O5 exceeded the reference sample at 7 and 28 days by approximately 3 and 5%, respectively.
Alternative materials such as industrial wastes and by-products can be easily and economically ut... more Alternative materials such as industrial wastes and by-products can be easily and economically utilised as raw material in Portland cement clinker manufacture. These materials are generated in abundance as a result of growing worldwide industrialisation. Two types of wastes from mining industry were used as secondary raw material in a concentration ranging from 1.4 to 3.5%. CEM I cements were obtained from these clinkers and compressive strength was determined. Different amounts varying between 3 and 7% of sludge generated in the effluent treatment plants of oil fields were added to a base raw mixture and the effect on the clinkering process was studied. The chemical and mineralogical compositions of the wastes and raw meals were determined. The raw mixes burnability containing different concentrations of wastes in various stages of burning in a laboratory furnace to form a Portland cement clinker was investigated. An improved burnability was noticed without affecting the clinker qu...
The durability of the materials based on hydraulic binders represents their basic characteristic ... more The durability of the materials based on hydraulic binders represents their basic characteristic and the behavior of the cement in acid corrosive environments represents a nowadays concern, due to the increasing aggressiveness of the more and more various environments in which the civil and industrial constructions are exploited. The paper presents the results obtained by studying the corrosive effect of 4 acids, inorganic and organic - hydrochloric acid, nitric acid, formic acid and acetic acid - on a type III/B cement, with a content of Portland cement and ∼70% blast furnace slag. The samples tested were cement pastes and plasters. Their behavior has been studied up to 180days of curing in acid solutions of 0.1mol/l concentration. The analyses carried-out were: mechanical strength measurements, chemical analyses of the core of the samples and of the corroded layers and X-ray diffraction analysis. The results of the analyses pointed-out the advanced degradation of the samples in al...
h i g h l i g h t s Sound absorbing concrete composites with embedded crumb rubber were made. Var... more h i g h l i g h t s Sound absorbing concrete composites with embedded crumb rubber were made. Various analysis techniques helped to identify the best mixture. Sound absorbing coefficient a was higher than 0.5 for 9 of 12 samples. a reached top values of 0.82 and 0.93 when favorable conditions existed. SOM and PCA techniques were used to identify correlations and similarities.
Revista Romana de materiale = Romanian journal of materials = RRM
The paper deals with aspects concerning the changes in the crystalline structure of alite doped w... more The paper deals with aspects concerning the changes in the crystalline structure of alite doped with phosphorus. A number of six samples containing different proportions of P2O5 were sintered in the laboratory by iterative thermal treatment at 1450°C. Thus, alite triclinic crystallisation was evinced irrespective of the content in P2O5. Also, major shifts of the Bragg reflections have been noticed, which indicates that phosphorus has been incorporated into the alite crystalline structure by its substituting for the silicon in the matrix. Moreover, formation of a new crystalline phase has been evinced when the P2O5 content exceeded 0.9% by weight.
The paper deals with aspects concerning the changes In the crystalline structure of alite doped w... more The paper deals with aspects concerning the changes In the crystalline structure of alite doped with phosphorus. A number of six samples containing different proportions of P 2 O 5 were sintered in the laboratory by iterative thermal treatment at 1450°C. Thus, alite triclinic crystallisation was evinced irrespective of the content in P 2 O 5 . Also, major shifts of the Bragg reflections have been noticed, which indicates that phosphorus has been Incorporated Into the alite crystalline structure by its substituting for the silicon in the matrix. Moreover, formation of a new crystalline phase has been evinced when the P 2 O 5 content exceeded 0.9% by weight.
Meat and bone meal (MBM) can be used in clinker manufacture as a secondary fuel together with the... more Meat and bone meal (MBM) can be used in clinker manufacture as a secondary fuel together with the conventional one. The substitution level of conventional fuel with the secondary one reached up to know was maximum 20 %. The high MBM content of phosphate raises problems regarding the incorporation of ash in the main clinker mineralogical phases. The aim of this paper was to determine the incorporation amount of phosphorus in Portland clinker minerals when MBM ash is added to the clinker raw material. The influence of this addition on the clinkering reactions was evaluated as well as the incorporation of phosphorus in alite and belite. Samples were prepared by additions from 0.07 to 0.88 wt.% of MBM ash to an industrial clinker raw material. The following techniques were applied to characterize the raw materials and the obtained clinkers: chemical analysis, selective dissolution of interstitial phase, X-ray diffraction and scanning electron microscopy. Selective dissolution of interst...
The present paper describes the application of IR spectroscopy to study the sulphate phase from o... more The present paper describes the application of IR spectroscopy to study the sulphate phase from ordinary Portland cement. A detailed discussion on vibration modes of sulphate ion is presented. The spectral bands of alkalisulphates which are present in Portland cement are discussed. It was considered aspects of the variations in relative intensity and frequency of spectral bands.
In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamin... more In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm−1 to 1415 cm−1 proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm−1 indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL...
Sound absorbing concrete composites with embedded crumb rubber were made. Various analysis techni... more Sound absorbing concrete composites with embedded crumb rubber were made. Various analysis techniques helped to identify the best mixture. Sound absorbing coefficient a was higher than 0.5 for 9 of 12 samples. a reached top values of 0.82 and 0.93 when favorable conditions existed. SOM and PCA techniques were used to identify correlations and similarities. a b s t r a c t The aim of this study is to characterize the acoustical behavior of concrete made with crumb rubber waste from sport fields. Concrete mixes with different water to cement ratio (0.45, 0.50 and 0.55) and crumb rubber dosages (0%, 5.0% and 7.5% by weight) were prepared. Properties examined for the nine mixes included compressive strength, apparent density, apparent porosity and acoustic tests. Four additional samples with a modeled intrinsic porosity were subjected to acoustic tests in the frequency range 200–3000 Hz. Some samples with high crumb rubber dosage were selected to study the interaction between crumb rubber wastes and cement matrix. Self-organizing maps (SOM) and Principal Component Analysis (PCA) methods were implemented to generate visual clustering and to find out the correlations between experimental data.
Alternative materials such as industrial wastes and by-products can be easily and economically ut... more Alternative materials such as industrial wastes and by-products can be easily and economically utilised as raw material in Portland cement clinker manufacture. These materials are generated in abundance as a result of growing worldwide industrialisation. Two types of wastes from mining industry were used as secondary raw material in a concentration ranging from 1.4 to 3.5%. CEM I cements were obtained from these clinkers and compressive strength was determined. Different amounts varying between 3 and 7% of sludge generated in the effluent treatment plants of oil fields were added to a base raw mixture and the effect on the clinkering process was studied. The chemical and mineralogical compositions of the wastes and raw meals were determined. The raw mixes burnability containing different concentrations of wastes in various stages of burning in a laboratory furnace to form a Portland cement clinker was investigated. An improved burnability was noticed without affecting the clinker quality. Materialele alternative, cum ar fi deșeurile și subprodusele industriale pot fi cu ușurință și economic utilizate ca materie primă în fabricarea clincherului de ciment Portland. Aceste materiale sunt generate din abundență, ca urmare a creșterii industrializării la nivel mondial. Două tipuri de deșeuri provenite din industria minieră au fost utilizate ca materie primă secundară într-o concentrație care a variat între 1,4 și 3,5%. Din aceste clinchere au fost obținute cimenturi CEM I pentru care s-a determinat rezistența la compresiune. Diferite cantități de nămol generat în stațiile de tratare a efluenților de la câmpurile petroliere care au variat între 3 și 7% au fost adăugate la un amestec de bază de materii prime, fiind analizat efectul asupra procesului de clincherizare. Au fost determinate compozițiile chimice și mineralogice ale deșeurilor și amestecurilor de materii prime. A fost investigată aptitudinea la ardere a amestecurilor de materii prime care conțin concentrații diferite de deșeuri, în diverse etape de ardere într-un cuptor de laborator. S-a observat o aptitudine la ardere îmbunătățită, fără a afecta calitatea clincherului.
International Journal of Molecular Sciences, Jul 31, 2021
Optical Properties of Composites Based on Poly (o-phenylenediamine), Poly (Vinylenefluoride) and ... more Optical Properties of Composites Based on Poly (o-phenylenediamine), Poly (Vinylenefluoride) and Double-Wall Carbon Nanotubes. Int.
The effect of the addition of small amounts of meat and bone meal (MBM) ash on the clinkering pro... more The effect of the addition of small amounts of meat and bone meal (MBM) ash on the clinkering process and on the hydraulic reactivity of obtained clinkers was studied. The study was aimed at simulating the clinker burning process in an industrial furnace that replaced up to 20 wt% conventional fuel with MBM used as alternative fuel. Laboratory clinkers were obtained by adding from 0.07 to 0.88 wt.% of MBM ash to an industrial raw mixture, and were compared with a clinker obtained without additions. The free lime content in the clinker increased steadily when the concentration of phosphorus was increased up to a level of 0.16 wt% P2O5 in the raw mixture. With higher phosphorus additions the free lime content increased only insignificantly. The results of X-ray microanalysis indicated that a maximum of 2.3 and 3.3% of the silicon sites were replaced by phosphorus in alite and belite, respectively. The clinker containing 0.6 wt% P2O5 slowed down the hydration process for approximately 1 day and thereafter began to exceed the degree of hydration of the reference sample. The values of degree of hydration of clinker rich in P2O5 exceeded the reference sample at 7 and 28 days by approximately 3 and 5%, respectively.
Alternative materials such as industrial wastes and by-products can be easily and economically ut... more Alternative materials such as industrial wastes and by-products can be easily and economically utilised as raw material in Portland cement clinker manufacture. These materials are generated in abundance as a result of growing worldwide industrialisation. Two types of wastes from mining industry were used as secondary raw material in a concentration ranging from 1.4 to 3.5%. CEM I cements were obtained from these clinkers and compressive strength was determined. Different amounts varying between 3 and 7% of sludge generated in the effluent treatment plants of oil fields were added to a base raw mixture and the effect on the clinkering process was studied. The chemical and mineralogical compositions of the wastes and raw meals were determined. The raw mixes burnability containing different concentrations of wastes in various stages of burning in a laboratory furnace to form a Portland cement clinker was investigated. An improved burnability was noticed without affecting the clinker qu...
The durability of the materials based on hydraulic binders represents their basic characteristic ... more The durability of the materials based on hydraulic binders represents their basic characteristic and the behavior of the cement in acid corrosive environments represents a nowadays concern, due to the increasing aggressiveness of the more and more various environments in which the civil and industrial constructions are exploited. The paper presents the results obtained by studying the corrosive effect of 4 acids, inorganic and organic - hydrochloric acid, nitric acid, formic acid and acetic acid - on a type III/B cement, with a content of Portland cement and ∼70% blast furnace slag. The samples tested were cement pastes and plasters. Their behavior has been studied up to 180days of curing in acid solutions of 0.1mol/l concentration. The analyses carried-out were: mechanical strength measurements, chemical analyses of the core of the samples and of the corroded layers and X-ray diffraction analysis. The results of the analyses pointed-out the advanced degradation of the samples in al...
h i g h l i g h t s Sound absorbing concrete composites with embedded crumb rubber were made. Var... more h i g h l i g h t s Sound absorbing concrete composites with embedded crumb rubber were made. Various analysis techniques helped to identify the best mixture. Sound absorbing coefficient a was higher than 0.5 for 9 of 12 samples. a reached top values of 0.82 and 0.93 when favorable conditions existed. SOM and PCA techniques were used to identify correlations and similarities.
Revista Romana de materiale = Romanian journal of materials = RRM
The paper deals with aspects concerning the changes in the crystalline structure of alite doped w... more The paper deals with aspects concerning the changes in the crystalline structure of alite doped with phosphorus. A number of six samples containing different proportions of P2O5 were sintered in the laboratory by iterative thermal treatment at 1450°C. Thus, alite triclinic crystallisation was evinced irrespective of the content in P2O5. Also, major shifts of the Bragg reflections have been noticed, which indicates that phosphorus has been incorporated into the alite crystalline structure by its substituting for the silicon in the matrix. Moreover, formation of a new crystalline phase has been evinced when the P2O5 content exceeded 0.9% by weight.
The paper deals with aspects concerning the changes In the crystalline structure of alite doped w... more The paper deals with aspects concerning the changes In the crystalline structure of alite doped with phosphorus. A number of six samples containing different proportions of P 2 O 5 were sintered in the laboratory by iterative thermal treatment at 1450°C. Thus, alite triclinic crystallisation was evinced irrespective of the content in P 2 O 5 . Also, major shifts of the Bragg reflections have been noticed, which indicates that phosphorus has been Incorporated Into the alite crystalline structure by its substituting for the silicon in the matrix. Moreover, formation of a new crystalline phase has been evinced when the P 2 O 5 content exceeded 0.9% by weight.
Meat and bone meal (MBM) can be used in clinker manufacture as a secondary fuel together with the... more Meat and bone meal (MBM) can be used in clinker manufacture as a secondary fuel together with the conventional one. The substitution level of conventional fuel with the secondary one reached up to know was maximum 20 %. The high MBM content of phosphate raises problems regarding the incorporation of ash in the main clinker mineralogical phases. The aim of this paper was to determine the incorporation amount of phosphorus in Portland clinker minerals when MBM ash is added to the clinker raw material. The influence of this addition on the clinkering reactions was evaluated as well as the incorporation of phosphorus in alite and belite. Samples were prepared by additions from 0.07 to 0.88 wt.% of MBM ash to an industrial clinker raw material. The following techniques were applied to characterize the raw materials and the obtained clinkers: chemical analysis, selective dissolution of interstitial phase, X-ray diffraction and scanning electron microscopy. Selective dissolution of interst...
The present paper describes the application of IR spectroscopy to study the sulphate phase from o... more The present paper describes the application of IR spectroscopy to study the sulphate phase from ordinary Portland cement. A detailed discussion on vibration modes of sulphate ion is presented. The spectral bands of alkalisulphates which are present in Portland cement are discussed. It was considered aspects of the variations in relative intensity and frequency of spectral bands.
In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamin... more In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm−1 to 1415 cm−1 proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm−1 indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL...
Sound absorbing concrete composites with embedded crumb rubber were made. Various analysis techni... more Sound absorbing concrete composites with embedded crumb rubber were made. Various analysis techniques helped to identify the best mixture. Sound absorbing coefficient a was higher than 0.5 for 9 of 12 samples. a reached top values of 0.82 and 0.93 when favorable conditions existed. SOM and PCA techniques were used to identify correlations and similarities. a b s t r a c t The aim of this study is to characterize the acoustical behavior of concrete made with crumb rubber waste from sport fields. Concrete mixes with different water to cement ratio (0.45, 0.50 and 0.55) and crumb rubber dosages (0%, 5.0% and 7.5% by weight) were prepared. Properties examined for the nine mixes included compressive strength, apparent density, apparent porosity and acoustic tests. Four additional samples with a modeled intrinsic porosity were subjected to acoustic tests in the frequency range 200–3000 Hz. Some samples with high crumb rubber dosage were selected to study the interaction between crumb rubber wastes and cement matrix. Self-organizing maps (SOM) and Principal Component Analysis (PCA) methods were implemented to generate visual clustering and to find out the correlations between experimental data.
Alternative materials such as industrial wastes and by-products can be easily and economically ut... more Alternative materials such as industrial wastes and by-products can be easily and economically utilised as raw material in Portland cement clinker manufacture. These materials are generated in abundance as a result of growing worldwide industrialisation. Two types of wastes from mining industry were used as secondary raw material in a concentration ranging from 1.4 to 3.5%. CEM I cements were obtained from these clinkers and compressive strength was determined. Different amounts varying between 3 and 7% of sludge generated in the effluent treatment plants of oil fields were added to a base raw mixture and the effect on the clinkering process was studied. The chemical and mineralogical compositions of the wastes and raw meals were determined. The raw mixes burnability containing different concentrations of wastes in various stages of burning in a laboratory furnace to form a Portland cement clinker was investigated. An improved burnability was noticed without affecting the clinker quality. Materialele alternative, cum ar fi deșeurile și subprodusele industriale pot fi cu ușurință și economic utilizate ca materie primă în fabricarea clincherului de ciment Portland. Aceste materiale sunt generate din abundență, ca urmare a creșterii industrializării la nivel mondial. Două tipuri de deșeuri provenite din industria minieră au fost utilizate ca materie primă secundară într-o concentrație care a variat între 1,4 și 3,5%. Din aceste clinchere au fost obținute cimenturi CEM I pentru care s-a determinat rezistența la compresiune. Diferite cantități de nămol generat în stațiile de tratare a efluenților de la câmpurile petroliere care au variat între 3 și 7% au fost adăugate la un amestec de bază de materii prime, fiind analizat efectul asupra procesului de clincherizare. Au fost determinate compozițiile chimice și mineralogice ale deșeurilor și amestecurilor de materii prime. A fost investigată aptitudinea la ardere a amestecurilor de materii prime care conțin concentrații diferite de deșeuri, în diverse etape de ardere într-un cuptor de laborator. S-a observat o aptitudine la ardere îmbunătățită, fără a afecta calitatea clincherului.
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