TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Andrić, Ljubiša
AU  - Pavlović, Vladimir
AU  - Mitić, Vojislav
PY  - 2017
UR  - http://rims.institutims.rs/handle/123456789/307
AB  - The properties of seven montmorillonite-rich bentonites of different geological origin were investigated prior and subsequent to mechano-chemical processing in an ultra-centrifugal mill. The objective of the experiment was altering the bentonite types and activation parameters in order to determine the optimal milling conditions that produce material which is physico-mechanically and microstructurally applicable as a binder replacement and sorbent in the construction composites. The efficiency of bentonite activation was assessed by chemometrics and Artificial neural networks mathematical modeling. Principal component analysis and analysis of variance were used in the observation of the influence of input variables (bentonite chemical composition) and process parameters (milling duration, rotor velocity) on the product characteristics: density, specific surface area, grain size and distribution, cation exchange capacity, melting point, compressive strength, shrinkage and porosity. When the ANN models for the observed responses, related to predicted bentonite characteristics and quality, were compared to experimental results, they correctly predicted the responses. The processed data also adequately fitted to the regression second order polynomial models. The SOP models, which showed r(2) values from 0.357 to 0.948, and were able to predict the observed responses in a wide range of processing parameters, while ANN models performed high prediction accuracy (0.776-0.901) and can be considered as precise for response variables prediction. The combination of the conducted mathematical analyses showed that that increase/decrease in output values was stabilized after 30 min of activation. Mathematically attained interpretations were correlated with the results of the instrumental analyses (XRD, DTA/TG, SEM) to confirm the adoption of B6 bentonite as a preferable type and 30 min as an optimal milling time for acquiring quality of clay powder that will be used in structural and thermal applications.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling
EP  - 2562
IS  - 2
SP  - 2549
VL  - 43
DO  - 10.1016/j.ceramint.2016.11.058
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Andrić, Ljubiša and Pavlović, Vladimir and Mitić, Vojislav",
year = "2017",
abstract = "The properties of seven montmorillonite-rich bentonites of different geological origin were investigated prior and subsequent to mechano-chemical processing in an ultra-centrifugal mill. The objective of the experiment was altering the bentonite types and activation parameters in order to determine the optimal milling conditions that produce material which is physico-mechanically and microstructurally applicable as a binder replacement and sorbent in the construction composites. The efficiency of bentonite activation was assessed by chemometrics and Artificial neural networks mathematical modeling. Principal component analysis and analysis of variance were used in the observation of the influence of input variables (bentonite chemical composition) and process parameters (milling duration, rotor velocity) on the product characteristics: density, specific surface area, grain size and distribution, cation exchange capacity, melting point, compressive strength, shrinkage and porosity. When the ANN models for the observed responses, related to predicted bentonite characteristics and quality, were compared to experimental results, they correctly predicted the responses. The processed data also adequately fitted to the regression second order polynomial models. The SOP models, which showed r(2) values from 0.357 to 0.948, and were able to predict the observed responses in a wide range of processing parameters, while ANN models performed high prediction accuracy (0.776-0.901) and can be considered as precise for response variables prediction. The combination of the conducted mathematical analyses showed that that increase/decrease in output values was stabilized after 30 min of activation. Mathematically attained interpretations were correlated with the results of the instrumental analyses (XRD, DTA/TG, SEM) to confirm the adoption of B6 bentonite as a preferable type and 30 min as an optimal milling time for acquiring quality of clay powder that will be used in structural and thermal applications.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling",
pages = "2562-2549",
number = "2",
volume = "43",
doi = "10.1016/j.ceramint.2016.11.058"
}

Terzić, A., Pezo, L., Andrić, L., Pavlović, V.,& Mitić, V.. (2017). Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling. in Ceramics International
Elsevier Sci Ltd, Oxford., 43(2), 2549-2562.
https://doi.org/10.1016/j.ceramint.2016.11.058

Terzić A, Pezo L, Andrić L, Pavlović V, Mitić V. Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling. in Ceramics International. 2017;43(2):2549-2562.
doi:10.1016/j.ceramint.2016.11.058 .

Terzić, Anja, Pezo, Lato, Andrić, Ljubiša, Pavlović, Vladimir, Mitić, Vojislav, "Optimization of bentonite clay mechano-chemical activation using artificial neural network modeling" in Ceramics International, 43, no. 2 (2017):2549-2562,
https://doi.org/10.1016/j.ceramint.2016.11.058 . .

TY  - CONF
AU  - Terzić, Anja
AU  - Mitić, Vojislav
AU  - Kocić, L.
AU  - Radojević, Zagorka
AU  - Pašalić, S.
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/302
AB  - Fractal geometry theory implied in a composite surface topographic analysis as a means of explanation of the structural characteristics has hardly been reported so far. This paper proposes a new method of roughness peaks curvature radii calculation and its application to the refractory composite surface tribological analysis. Fractal geometry method is introduced via calculation of asperity radius, by introducing a fractal concept of curvature radii of surfaces, depending on the observation scale and also numerically depending on horizontal lines intercepted by the investigated profile. The dependence of the calculated radii on the fractal geometry of the studied curves was established and the notion of peak was mathematically formulated. The efficiency of the method was tested by simulations of fractal curves described by Brownian motions. Microstructural investigations were carried out using a scanning electron microscope. The correlation between microstructure and properties of the investigated refractory composite, based on fractal geometry and contact surface probability, has been developed. Using the fractals of the contact surfaces of grains, a reconstruction of microstructure configuration, as grain shapes or inter-granular contacts, has been successfully performed. Obtained results indicated that fractal analysis of contact surfaces of different shapes was very important for the prognosis of refractory composite properties and behavior. The morphology of composite grains and surfaces highlighted the validity of developing new structure analytical methods based on different grain shape geometries. The novel approach to the investigation of refractory composite characteristics was successfully conducted, as a result introducing fractal identification as a means of evaluating and predicting material performances.
PB  - American Ceramic Society
C3  - Ceramic Engineering and Science Proceedings
T1  - Novel application of fractal analysis in refractory composite microsturctural characterization
EP  - 85
IS  - 2
SP  - 73
VL  - 36
UR  - https://hdl.handle.net/21.15107/rcub_rims_302
ER  - 

@conference{
author = "Terzić, Anja and Mitić, Vojislav and Kocić, L. and Radojević, Zagorka and Pašalić, S.",
year = "2016",
abstract = "Fractal geometry theory implied in a composite surface topographic analysis as a means of explanation of the structural characteristics has hardly been reported so far. This paper proposes a new method of roughness peaks curvature radii calculation and its application to the refractory composite surface tribological analysis. Fractal geometry method is introduced via calculation of asperity radius, by introducing a fractal concept of curvature radii of surfaces, depending on the observation scale and also numerically depending on horizontal lines intercepted by the investigated profile. The dependence of the calculated radii on the fractal geometry of the studied curves was established and the notion of peak was mathematically formulated. The efficiency of the method was tested by simulations of fractal curves described by Brownian motions. Microstructural investigations were carried out using a scanning electron microscope. The correlation between microstructure and properties of the investigated refractory composite, based on fractal geometry and contact surface probability, has been developed. Using the fractals of the contact surfaces of grains, a reconstruction of microstructure configuration, as grain shapes or inter-granular contacts, has been successfully performed. Obtained results indicated that fractal analysis of contact surfaces of different shapes was very important for the prognosis of refractory composite properties and behavior. The morphology of composite grains and surfaces highlighted the validity of developing new structure analytical methods based on different grain shape geometries. The novel approach to the investigation of refractory composite characteristics was successfully conducted, as a result introducing fractal identification as a means of evaluating and predicting material performances.",
publisher = "American Ceramic Society",
journal = "Ceramic Engineering and Science Proceedings",
title = "Novel application of fractal analysis in refractory composite microsturctural characterization",
pages = "85-73",
number = "2",
volume = "36",
url = "https://hdl.handle.net/21.15107/rcub_rims_302"
}

Terzić, A., Mitić, V., Kocić, L., Radojević, Z.,& Pašalić, S.. (2016). Novel application of fractal analysis in refractory composite microsturctural characterization. in Ceramic Engineering and Science Proceedings
American Ceramic Society., 36(2), 73-85.
https://hdl.handle.net/21.15107/rcub_rims_302

Terzić A, Mitić V, Kocić L, Radojević Z, Pašalić S. Novel application of fractal analysis in refractory composite microsturctural characterization. in Ceramic Engineering and Science Proceedings. 2016;36(2):73-85.
https://hdl.handle.net/21.15107/rcub_rims_302 .

Terzić, Anja, Mitić, Vojislav, Kocić, L., Radojević, Zagorka, Pašalić, S., "Novel application of fractal analysis in refractory composite microsturctural characterization" in Ceramic Engineering and Science Proceedings, 36, no. 2 (2016):73-85,
https://hdl.handle.net/21.15107/rcub_rims_302 .

TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Mitić, Vojislav
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/290
AB  - The objective of this study was to investigate the clay drying as a unit operation in the refractory materials processing. Two clays that varied in chemical and mineralogical compositions were experimentally tested in a laboratory dryer. The results obtained on the green samples prior to drying indicated that clays have adequate plasticity and refractoriness for application in shaped refractories. The operating parameters of the dryer were regulated: temperature ranged from 40 to 60 degrees C, humidity increased in the interval 30-70%; and the airstream rate was 1.3 m/s. The correlation analysis between operating parameters and calculated and/or measured drying outputs was conducted for better comprehension of the clay's role as a refractory binder. Subsequently, a mathematical optimization of the drying regime was conveyed. The effect of the variables (operation parameters) on the drying parameters (critical moisture, equilibrium moisture, dryness degree, etc.) was compared and evaluated. The response surface method, standard score analysis, cluster method, and principal component analysis were used as a means of the drying regime optimization. Assessment of the drying regime impact on the dried samples quality highlighted optimal result for both clay types: SS=0.95, temperature 50 degrees C, and humidity 40%. Multiple comparison analyses pointed out that optimized combination of the drying operation parameters decreases the quantity of conducted tests. Furthermore, optimal combination of drying parameters reduces negative effects of clay binder inherent properties on the resulting product which in return improves energetic and economic sustainability of refractories production.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Optimization of drying through analytical modeling: clays as bonding agents in refractory materials
EP  - 6311
IS  - 5
SP  - 6301
VL  - 42
DO  - 10.1016/j.ceramint.2016.01.018
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Mitić, Vojislav",
year = "2016",
abstract = "The objective of this study was to investigate the clay drying as a unit operation in the refractory materials processing. Two clays that varied in chemical and mineralogical compositions were experimentally tested in a laboratory dryer. The results obtained on the green samples prior to drying indicated that clays have adequate plasticity and refractoriness for application in shaped refractories. The operating parameters of the dryer were regulated: temperature ranged from 40 to 60 degrees C, humidity increased in the interval 30-70%; and the airstream rate was 1.3 m/s. The correlation analysis between operating parameters and calculated and/or measured drying outputs was conducted for better comprehension of the clay's role as a refractory binder. Subsequently, a mathematical optimization of the drying regime was conveyed. The effect of the variables (operation parameters) on the drying parameters (critical moisture, equilibrium moisture, dryness degree, etc.) was compared and evaluated. The response surface method, standard score analysis, cluster method, and principal component analysis were used as a means of the drying regime optimization. Assessment of the drying regime impact on the dried samples quality highlighted optimal result for both clay types: SS=0.95, temperature 50 degrees C, and humidity 40%. Multiple comparison analyses pointed out that optimized combination of the drying operation parameters decreases the quantity of conducted tests. Furthermore, optimal combination of drying parameters reduces negative effects of clay binder inherent properties on the resulting product which in return improves energetic and economic sustainability of refractories production.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Optimization of drying through analytical modeling: clays as bonding agents in refractory materials",
pages = "6311-6301",
number = "5",
volume = "42",
doi = "10.1016/j.ceramint.2016.01.018"
}

Terzić, A., Pezo, L.,& Mitić, V.. (2016). Optimization of drying through analytical modeling: clays as bonding agents in refractory materials. in Ceramics International
Elsevier Sci Ltd, Oxford., 42(5), 6301-6311.
https://doi.org/10.1016/j.ceramint.2016.01.018

Terzić A, Pezo L, Mitić V. Optimization of drying through analytical modeling: clays as bonding agents in refractory materials. in Ceramics International. 2016;42(5):6301-6311.
doi:10.1016/j.ceramint.2016.01.018 .

Terzić, Anja, Pezo, Lato, Mitić, Vojislav, "Optimization of drying through analytical modeling: clays as bonding agents in refractory materials" in Ceramics International, 42, no. 5 (2016):6301-6311,
https://doi.org/10.1016/j.ceramint.2016.01.018 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Radojević, Zagorka
AU  - Pavlović, Ljubica
AU  - Pavlović, Vladimir
AU  - Mitić, Vojislav
PY  - 2015
UR  - http://rims.institutims.rs/handle/123456789/281
AB  - In this study, the feasibility of using fly ash to manufacture high-temperature mortars was investigated. The investigation was set to define preliminary characteristics of new types of mortars based on ordinary and/or refractory cement with fly ash addition, and to establish mutual correlation between thermally induced changes of mineral phases, microstructure, and final performances of the mortars. New mortars, made up of 21% cement (PC-CEM I 42.5R/HAC-Secar 70/71), 70% river sand, and 9% fly ash, were chemically, physically, and mechanically characterized to determine possibilities of fly ash re-utilization for high-temperature purposes. The fly ash samples, which originated from four different power plants, were mechanically activated. Mortars were heat-treated up to 1300 degrees C in a laboratory tunnel furnace with retention time 2 h. Thermal stability of crystalline phases were studied by differential thermal analysis (DTA); thermally induced changes in mineral phase composition were analyzed by XRD; and microstructure were investigated by scanning electron microscopy. Correlated results of DTA, XRD, and SEM analyses indicated initiation of sintering processes at approximately 1300 degrees C and formation of thermally stable minerals (rankinite, gehlenite, anorthite, cristobalite). The investigation highlights a sustainable approach of using fly ash in developing ecofriendly mortars for high-temperature application.
PB  - Wiley, Hoboken
T2  - International Journal of Applied Ceramic Technology
T1  - Novel Utilization of Fly Ash for High-Temperature Mortars: Phase Composition, Microstructure and Performances Correlation
EP  - 146
IS  - 1
SP  - 133
VL  - 12
DO  - 10.1111/ijac.12135
ER  - 

@article{
author = "Terzić, Anja and Radojević, Zagorka and Pavlović, Ljubica and Pavlović, Vladimir and Mitić, Vojislav",
year = "2015",
abstract = "In this study, the feasibility of using fly ash to manufacture high-temperature mortars was investigated. The investigation was set to define preliminary characteristics of new types of mortars based on ordinary and/or refractory cement with fly ash addition, and to establish mutual correlation between thermally induced changes of mineral phases, microstructure, and final performances of the mortars. New mortars, made up of 21% cement (PC-CEM I 42.5R/HAC-Secar 70/71), 70% river sand, and 9% fly ash, were chemically, physically, and mechanically characterized to determine possibilities of fly ash re-utilization for high-temperature purposes. The fly ash samples, which originated from four different power plants, were mechanically activated. Mortars were heat-treated up to 1300 degrees C in a laboratory tunnel furnace with retention time 2 h. Thermal stability of crystalline phases were studied by differential thermal analysis (DTA); thermally induced changes in mineral phase composition were analyzed by XRD; and microstructure were investigated by scanning electron microscopy. Correlated results of DTA, XRD, and SEM analyses indicated initiation of sintering processes at approximately 1300 degrees C and formation of thermally stable minerals (rankinite, gehlenite, anorthite, cristobalite). The investigation highlights a sustainable approach of using fly ash in developing ecofriendly mortars for high-temperature application.",
publisher = "Wiley, Hoboken",
journal = "International Journal of Applied Ceramic Technology",
title = "Novel Utilization of Fly Ash for High-Temperature Mortars: Phase Composition, Microstructure and Performances Correlation",
pages = "146-133",
number = "1",
volume = "12",
doi = "10.1111/ijac.12135"
}

Terzić, A., Radojević, Z., Pavlović, L., Pavlović, V.,& Mitić, V.. (2015). Novel Utilization of Fly Ash for High-Temperature Mortars: Phase Composition, Microstructure and Performances Correlation. in International Journal of Applied Ceramic Technology
Wiley, Hoboken., 12(1), 133-146.
https://doi.org/10.1111/ijac.12135

Terzić A, Radojević Z, Pavlović L, Pavlović V, Mitić V. Novel Utilization of Fly Ash for High-Temperature Mortars: Phase Composition, Microstructure and Performances Correlation. in International Journal of Applied Ceramic Technology. 2015;12(1):133-146.
doi:10.1111/ijac.12135 .

Terzić, Anja, Radojević, Zagorka, Pavlović, Ljubica, Pavlović, Vladimir, Mitić, Vojislav, "Novel Utilization of Fly Ash for High-Temperature Mortars: Phase Composition, Microstructure and Performances Correlation" in International Journal of Applied Ceramic Technology, 12, no. 1 (2015):133-146,
https://doi.org/10.1111/ijac.12135 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Mitić, Vojislav
AU  - Kocić, Lj.
AU  - Radojević, Zagorka
AU  - Pašalić, S.
PY  - 2015
UR  - http://rims.institutims.rs/handle/123456789/269
AB  - The surface topography analysis via fractals as a means of explanation of composite materials mechanical and microstructural characteristics has hardly been reported so far. This study proposes a method of fractal analysis and its application to refractory bauxite concrete surface tribological investigation. Fractal dimension, profilegrams and fast Fourier transform method are introduced and supported by the adequate software for analysing contours and surface roughness, depending on the observation scale and also numerically depending on horizontal lines intercepted by the investigated profile. Also, the Richardson method and Kaye modification are applied to distinguish textured and structured aspect of grain contour geometry. Microstructural investigation was carried out using a scanning electron microscope. Using the fractals of the grains contact surfaces, a reconstruction of microstructure configuration, as grains shapes or inter-granular contacts, has been performed. Obtained results indicated that fractal analyses of contact surfaces of different shapes were very important for the prognosis of the concrete behaviour. The novel approach to the investigation of refractory concrete properties was successfully conducted, as a result introducing fractal identification as a means of composite materials performances evaluation.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - Mechanical Properties and Microstructure Fractal Analysis of Refractory Bauxite Concrete
EP  - 346
IS  - 3
SP  - 331
VL  - 47
DO  - 10.2298/SOS1503331T
ER  - 

@article{
author = "Terzić, Anja and Mitić, Vojislav and Kocić, Lj. and Radojević, Zagorka and Pašalić, S.",
year = "2015",
abstract = "The surface topography analysis via fractals as a means of explanation of composite materials mechanical and microstructural characteristics has hardly been reported so far. This study proposes a method of fractal analysis and its application to refractory bauxite concrete surface tribological investigation. Fractal dimension, profilegrams and fast Fourier transform method are introduced and supported by the adequate software for analysing contours and surface roughness, depending on the observation scale and also numerically depending on horizontal lines intercepted by the investigated profile. Also, the Richardson method and Kaye modification are applied to distinguish textured and structured aspect of grain contour geometry. Microstructural investigation was carried out using a scanning electron microscope. Using the fractals of the grains contact surfaces, a reconstruction of microstructure configuration, as grains shapes or inter-granular contacts, has been performed. Obtained results indicated that fractal analyses of contact surfaces of different shapes were very important for the prognosis of the concrete behaviour. The novel approach to the investigation of refractory concrete properties was successfully conducted, as a result introducing fractal identification as a means of composite materials performances evaluation.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "Mechanical Properties and Microstructure Fractal Analysis of Refractory Bauxite Concrete",
pages = "346-331",
number = "3",
volume = "47",
doi = "10.2298/SOS1503331T"
}

Terzić, A., Mitić, V., Kocić, Lj., Radojević, Z.,& Pašalić, S.. (2015). Mechanical Properties and Microstructure Fractal Analysis of Refractory Bauxite Concrete. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 47(3), 331-346.
https://doi.org/10.2298/SOS1503331T

Terzić A, Mitić V, Kocić L, Radojević Z, Pašalić S. Mechanical Properties and Microstructure Fractal Analysis of Refractory Bauxite Concrete. in Science of Sintering. 2015;47(3):331-346.
doi:10.2298/SOS1503331T .

Terzić, Anja, Mitić, Vojislav, Kocić, Lj., Radojević, Zagorka, Pašalić, S., "Mechanical Properties and Microstructure Fractal Analysis of Refractory Bauxite Concrete" in Science of Sintering, 47, no. 3 (2015):331-346,
https://doi.org/10.2298/SOS1503331T . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Mitić, Vojislav
AU  - Radojević, Zagorka
PY  - 2015
UR  - http://rims.institutims.rs/handle/123456789/267
AB  - The effect of the application of pelletized fly ash based aggregates obtained through different processing techniques on the behavior of lightweight concretes was analyzed. Experimental program implied production of four lightweight artificial aggregates-cold bonded and sintered pellets based on either mechanically activated or non-activated low-calcium fly ash and water glass. The lightweight concrete behavior was compared to that of normal-weight concrete through compressive strength, flexural strength, porosity, shrinkage, and modulus of elasticity investigation. Differences in concretes characteristics were discussed with SEM imagining support. The statistical analysis of lightweight aggregate and ash properties contribution on concrete performances was realized by analysis variance model (ANOVA). Optimal production combination that maximizes lightweight concrete performance was determined by employing response surface methodology. An increase in concrete strength induced by the increase in ash fineness was noticed. Mechanical activation also had effect on the pellets sintering period and sintering temperature reduction. The 28- and 56-day lightweight concrete specimens exhibited properties that met the requirements for normal-weight concretes. Finally, the ideal combinations of ash pellets production parameters and properties that gave the lightweight concrete with behavior matching to that of standard concrete were established. The production capability of lightweight concrete with advanced performances based on artificial aggregate approves the principle of waste material reusing and enables cleaner and economically sustainable concrete manufacturing procedure.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Artificial fly ash based aggregates properties influence on lightweight concrete performances
EP  - 2726
IS  - 2
SP  - 2714
VL  - 41
DO  - 10.1016/j.ceramint.2014.10.086
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Mitić, Vojislav and Radojević, Zagorka",
year = "2015",
abstract = "The effect of the application of pelletized fly ash based aggregates obtained through different processing techniques on the behavior of lightweight concretes was analyzed. Experimental program implied production of four lightweight artificial aggregates-cold bonded and sintered pellets based on either mechanically activated or non-activated low-calcium fly ash and water glass. The lightweight concrete behavior was compared to that of normal-weight concrete through compressive strength, flexural strength, porosity, shrinkage, and modulus of elasticity investigation. Differences in concretes characteristics were discussed with SEM imagining support. The statistical analysis of lightweight aggregate and ash properties contribution on concrete performances was realized by analysis variance model (ANOVA). Optimal production combination that maximizes lightweight concrete performance was determined by employing response surface methodology. An increase in concrete strength induced by the increase in ash fineness was noticed. Mechanical activation also had effect on the pellets sintering period and sintering temperature reduction. The 28- and 56-day lightweight concrete specimens exhibited properties that met the requirements for normal-weight concretes. Finally, the ideal combinations of ash pellets production parameters and properties that gave the lightweight concrete with behavior matching to that of standard concrete were established. The production capability of lightweight concrete with advanced performances based on artificial aggregate approves the principle of waste material reusing and enables cleaner and economically sustainable concrete manufacturing procedure.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Artificial fly ash based aggregates properties influence on lightweight concrete performances",
pages = "2726-2714",
number = "2",
volume = "41",
doi = "10.1016/j.ceramint.2014.10.086"
}

Terzić, A., Pezo, L., Mitić, V.,& Radojević, Z.. (2015). Artificial fly ash based aggregates properties influence on lightweight concrete performances. in Ceramics International
Elsevier Sci Ltd, Oxford., 41(2), 2714-2726.
https://doi.org/10.1016/j.ceramint.2014.10.086

Terzić A, Pezo L, Mitić V, Radojević Z. Artificial fly ash based aggregates properties influence on lightweight concrete performances. in Ceramics International. 2015;41(2):2714-2726.
doi:10.1016/j.ceramint.2014.10.086 .

Terzić, Anja, Pezo, Lato, Mitić, Vojislav, Radojević, Zagorka, "Artificial fly ash based aggregates properties influence on lightweight concrete performances" in Ceramics International, 41, no. 2 (2015):2714-2726,
https://doi.org/10.1016/j.ceramint.2014.10.086 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Pezo, Lato
AU  - Andrić, Ljubiša
AU  - Mitić, Vojislav
PY  - 2015
UR  - http://rims.institutims.rs/handle/123456789/271
AB  - The impact of the mechanical processing parameters on the alumina grain-size distribution affiliated characteristics and on the gamma to alpha phase transformation rate was investigated. The moderation in the alumina samples behavior has been correlated to the granulometric and mineralogical changes induced by activation via an ultra-centrifugal mill. The assessment of the activation process variables influence on the final quality of the product parameters was conveyed in order to optimize the mechanical treatment of the alumina, which otherwise could be regarded as either energetically or economically unsustainable procedure. The Response Surface Method, Standard Score Analysis and Principal Component Analysis were applied as means of the mechanical activation optimization. The r(2) values obtained by developed models were in range from 0.816 to 0.988. The established mathematical models were able to precisely predict the quality parameters in a broad range of processing parameters. The Standard Score Analysis emphasized that the optimal output sample was obtained using a sieve mesh of 120 mu m set of processing parameters (SS=0.96). Diverse comparison analyses disclosed that the optimal set of activation process parameters could reduce the negative effect of gamma-alumina samples immanent properties on the final score, and furthermore to enhance the rate of gamma to alpha transition which would improve energetic and economic sustainability of the alumina phase transformation procedure.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Analytical modeling of activation procedure applied in alpha-alumina thermo-mechanical synthesis
EP  - 11917
IS  - 9
SP  - 11908
VL  - 41
DO  - 10.1016/j.ceramint.2015.05.158
ER  - 

@article{
author = "Terzić, Anja and Pezo, Lato and Andrić, Ljubiša and Mitić, Vojislav",
year = "2015",
abstract = "The impact of the mechanical processing parameters on the alumina grain-size distribution affiliated characteristics and on the gamma to alpha phase transformation rate was investigated. The moderation in the alumina samples behavior has been correlated to the granulometric and mineralogical changes induced by activation via an ultra-centrifugal mill. The assessment of the activation process variables influence on the final quality of the product parameters was conveyed in order to optimize the mechanical treatment of the alumina, which otherwise could be regarded as either energetically or economically unsustainable procedure. The Response Surface Method, Standard Score Analysis and Principal Component Analysis were applied as means of the mechanical activation optimization. The r(2) values obtained by developed models were in range from 0.816 to 0.988. The established mathematical models were able to precisely predict the quality parameters in a broad range of processing parameters. The Standard Score Analysis emphasized that the optimal output sample was obtained using a sieve mesh of 120 mu m set of processing parameters (SS=0.96). Diverse comparison analyses disclosed that the optimal set of activation process parameters could reduce the negative effect of gamma-alumina samples immanent properties on the final score, and furthermore to enhance the rate of gamma to alpha transition which would improve energetic and economic sustainability of the alumina phase transformation procedure.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Analytical modeling of activation procedure applied in alpha-alumina thermo-mechanical synthesis",
pages = "11917-11908",
number = "9",
volume = "41",
doi = "10.1016/j.ceramint.2015.05.158"
}

Terzić, A., Pezo, L., Andrić, L.,& Mitić, V.. (2015). Analytical modeling of activation procedure applied in alpha-alumina thermo-mechanical synthesis. in Ceramics International
Elsevier Sci Ltd, Oxford., 41(9), 11908-11917.
https://doi.org/10.1016/j.ceramint.2015.05.158

Terzić A, Pezo L, Andrić L, Mitić V. Analytical modeling of activation procedure applied in alpha-alumina thermo-mechanical synthesis. in Ceramics International. 2015;41(9):11908-11917.
doi:10.1016/j.ceramint.2015.05.158 .

Terzić, Anja, Pezo, Lato, Andrić, Ljubiša, Mitić, Vojislav, "Analytical modeling of activation procedure applied in alpha-alumina thermo-mechanical synthesis" in Ceramics International, 41, no. 9 (2015):11908-11917,
https://doi.org/10.1016/j.ceramint.2015.05.158 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Andrić, Ljubiša
AU  - Mitić, Vojislav
PY  - 2014
UR  - http://rims.institutims.rs/handle/123456789/242
AB  - A growing demand for refractory castables with advanced properties has given rise to a continuous technological evolution and highlighted the necessity for secondary raw materials reapplication even in refractory industry. For the experiment, refractory shotcretes with the same matrix composition were prepared from 30 wt% of high aluminate cement, 40 wt% of bauxite aggregate and 30 wt% of chamotte filler. The request for obtaining a low-cement castable is fulfilled by application of mechanically activated coal ash as microfiller in one of the bauxite shotcretes. The fly ash was activated by means of vibratory disc mill and ultra-centrifugal mill, and results were compared. The shotcrete samples were dried at 110 degrees C during 24 h to create specimens for investigation of mechanical and thermal properties. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400 degrees C. At maximal 1400 degrees C, the bauxite shotcretes were mainly composed of anorthite, corundum, mullite and cristobalite. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis (DTA) at three different heating rates. DTA measurements showed different activation energies for ordinary bauxite shotcrete and shotcrete with microfiller. The evolution of the refractory shotcretes properties was investigated and correlated with microstructural changes induced by temperature and microfiller addition. The combination of advantages in investigated refractory shotcretes makes them suitable for use in severe conditions at high temperature applications especially in refractory industries.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation
EP  - 12065
IS  - 8
SP  - 12055
VL  - 40
DO  - 10.1016/j.ceramint.2014.04.045
ER  - 

@article{
author = "Terzić, Anja and Andrić, Ljubiša and Mitić, Vojislav",
year = "2014",
abstract = "A growing demand for refractory castables with advanced properties has given rise to a continuous technological evolution and highlighted the necessity for secondary raw materials reapplication even in refractory industry. For the experiment, refractory shotcretes with the same matrix composition were prepared from 30 wt% of high aluminate cement, 40 wt% of bauxite aggregate and 30 wt% of chamotte filler. The request for obtaining a low-cement castable is fulfilled by application of mechanically activated coal ash as microfiller in one of the bauxite shotcretes. The fly ash was activated by means of vibratory disc mill and ultra-centrifugal mill, and results were compared. The shotcrete samples were dried at 110 degrees C during 24 h to create specimens for investigation of mechanical and thermal properties. The properties have been studied at temperatures ranging from room temperature to adopted maximal temperature 1400 degrees C. At maximal 1400 degrees C, the bauxite shotcretes were mainly composed of anorthite, corundum, mullite and cristobalite. Mechanisms of hydration and sintering were investigated by means of differential thermal analysis (DTA) at three different heating rates. DTA measurements showed different activation energies for ordinary bauxite shotcrete and shotcrete with microfiller. The evolution of the refractory shotcretes properties was investigated and correlated with microstructural changes induced by temperature and microfiller addition. The combination of advantages in investigated refractory shotcretes makes them suitable for use in severe conditions at high temperature applications especially in refractory industries.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation",
pages = "12065-12055",
number = "8",
volume = "40",
doi = "10.1016/j.ceramint.2014.04.045"
}

Terzić, A., Andrić, L.,& Mitić, V.. (2014). Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation. in Ceramics International
Elsevier Sci Ltd, Oxford., 40(8), 12055-12065.
https://doi.org/10.1016/j.ceramint.2014.04.045

Terzić A, Andrić L, Mitić V. Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation. in Ceramics International. 2014;40(8):12055-12065.
doi:10.1016/j.ceramint.2014.04.045 .

Terzić, Anja, Andrić, Ljubiša, Mitić, Vojislav, "Mechanically activated coal ash as refractory bauxite shotcrete microfiller: Thermal interactions mechanism investigation" in Ceramics International, 40, no. 8 (2014):12055-12065,
https://doi.org/10.1016/j.ceramint.2014.04.045 . .

TY  - JOUR
AU  - Terzić, Anja
AU  - Andrić, Ljubiša
AU  - Mitić, Vojislav
PY  - 2014
UR  - http://rims.institutims.rs/handle/123456789/243
AB  - In this study, the feasibility of alumina phase transition enhancement by mechanical activation was conducted. It was showed that the milling environment plays an important role on the physical, chemical and thermal behavior of the alumina powder utilized as refractory component material. The aim of the investigation was to increase the reactivity of the starting gamma-Al2O3 by mechanical treatment in two types of high-energy activators - vibratory disc mill and vibratory ball mill. In continuation, the decrease of the subsequent sintering temperature as well as the treatment duration would be induced by making the transition into final thermo-stable alpha-Al2O3 modification easier and faster. Full factorial experiment was conducted and the results were analyzed by the proposed mathematical model in order to understand the effects of the activation process variables on the amount and physical characteristics of the synthesized (activated and subsequently thermally treated) product and to establish the optimal activation period. As the result of the analysis, operation parameters of the activator and activation period were found to be the most important factors. The initial gamma-Al2O3 and synthesized alpha-Al2O3 were thoroughly analyzed by DTA, XRD, IR and SEM methods. Thermal behavior of gamma and alpha-modification were studied by differential thermal analysis conducted in the same environment, under same heating rates. X-ray diffraction analysis gave reliable identification of the crystal phases and changes in crystallinity of treated alumina. Based on XRD peak intensity measurements, the gamma-Al2O3 almost completely passed (95%) into alpha-Al2O3 after 180 min of activation in vibratory ball mill and subsequent thermal treatment (2 h/1200 degrees C). SEM microphotographs with accompanying image analysis PC program highlighted changes in size and shape of particles of initial and synthesized Al2O3. Synthesized Al2O3 exquisite thermal behavior characteristic for refractory compounds, demonstrated that it is possible to obtain alpha-alumina at lower transformation temperatures in shorter time intervals by applying mechanical activation.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of gamma to alpha phase transformation mechanism
EP  - 14863
IS  - 9
SP  - 14851
VL  - 40
DO  - 10.1016/j.ceramint.2014.06.080
ER  - 

@article{
author = "Terzić, Anja and Andrić, Ljubiša and Mitić, Vojislav",
year = "2014",
abstract = "In this study, the feasibility of alumina phase transition enhancement by mechanical activation was conducted. It was showed that the milling environment plays an important role on the physical, chemical and thermal behavior of the alumina powder utilized as refractory component material. The aim of the investigation was to increase the reactivity of the starting gamma-Al2O3 by mechanical treatment in two types of high-energy activators - vibratory disc mill and vibratory ball mill. In continuation, the decrease of the subsequent sintering temperature as well as the treatment duration would be induced by making the transition into final thermo-stable alpha-Al2O3 modification easier and faster. Full factorial experiment was conducted and the results were analyzed by the proposed mathematical model in order to understand the effects of the activation process variables on the amount and physical characteristics of the synthesized (activated and subsequently thermally treated) product and to establish the optimal activation period. As the result of the analysis, operation parameters of the activator and activation period were found to be the most important factors. The initial gamma-Al2O3 and synthesized alpha-Al2O3 were thoroughly analyzed by DTA, XRD, IR and SEM methods. Thermal behavior of gamma and alpha-modification were studied by differential thermal analysis conducted in the same environment, under same heating rates. X-ray diffraction analysis gave reliable identification of the crystal phases and changes in crystallinity of treated alumina. Based on XRD peak intensity measurements, the gamma-Al2O3 almost completely passed (95%) into alpha-Al2O3 after 180 min of activation in vibratory ball mill and subsequent thermal treatment (2 h/1200 degrees C). SEM microphotographs with accompanying image analysis PC program highlighted changes in size and shape of particles of initial and synthesized Al2O3. Synthesized Al2O3 exquisite thermal behavior characteristic for refractory compounds, demonstrated that it is possible to obtain alpha-alumina at lower transformation temperatures in shorter time intervals by applying mechanical activation.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of gamma to alpha phase transformation mechanism",
pages = "14863-14851",
number = "9",
volume = "40",
doi = "10.1016/j.ceramint.2014.06.080"
}

Terzić, A., Andrić, L.,& Mitić, V.. (2014). Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of gamma to alpha phase transformation mechanism. in Ceramics International
Elsevier Sci Ltd, Oxford., 40(9), 14851-14863.
https://doi.org/10.1016/j.ceramint.2014.06.080

Terzić A, Andrić L, Mitić V. Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of gamma to alpha phase transformation mechanism. in Ceramics International. 2014;40(9):14851-14863.
doi:10.1016/j.ceramint.2014.06.080 .

Terzić, Anja, Andrić, Ljubiša, Mitić, Vojislav, "Assessment of intensive grinding effects on alumina as refractory compound: Acceleration of gamma to alpha phase transformation mechanism" in Ceramics International, 40, no. 9 (2014):14851-14863,
https://doi.org/10.1016/j.ceramint.2014.06.080 . .

TY  - CONF
AU  - Terzić, Anja
AU  - Pavlović, Ljubica
AU  - Mitić, Vojislav
PY  - 2011
UR  - http://rims.institutims.rs/handle/123456789/148
AB  - Aim of this paper is to establish the correlation between sintering process, porosity and important thermo-mechanical property of refractory concrete, i.e. creep. Creep deformation was investigated according to standard laboratory procedure applied at three temperatures: 1200, 1300 and 1400 degrees C. Corundum and bauxite based refractory concretes were investigated. The concretes are varying in chemical and mineralogical composition. Both loss of strength and degradation of material occur when refractory concrete is subjected to increased temperature and compressive static load. Measuring of thermo-mechanical properties can indicate and monitor the changes within microstructure. Variation of refractory concrete microstructure, as a consequence of sintering process, during exposure to constant compressive load and constant elevated temperature during certain time-intervals was investigated using scanning electron microscope and Image Pro Plus program for image analysis. Obtained results of the investigation proved that creep can be useful method when type of refractory concrete is to be chosen for an application.
PB  - American Ceramic Society
C3  - Mechanical Properties and Performance of Engineering Ceramics and Composites Vi
T1  - Determination of apparent porosity level of refractory concrete using ultrasonic pulse velocity technique and image analysis
EP  - 161
IS  - 2
SP  - 151
VL  - 32
UR  - https://hdl.handle.net/21.15107/rcub_rims_148
ER  - 

@conference{
author = "Terzić, Anja and Pavlović, Ljubica and Mitić, Vojislav",
year = "2011",
abstract = "Aim of this paper is to establish the correlation between sintering process, porosity and important thermo-mechanical property of refractory concrete, i.e. creep. Creep deformation was investigated according to standard laboratory procedure applied at three temperatures: 1200, 1300 and 1400 degrees C. Corundum and bauxite based refractory concretes were investigated. The concretes are varying in chemical and mineralogical composition. Both loss of strength and degradation of material occur when refractory concrete is subjected to increased temperature and compressive static load. Measuring of thermo-mechanical properties can indicate and monitor the changes within microstructure. Variation of refractory concrete microstructure, as a consequence of sintering process, during exposure to constant compressive load and constant elevated temperature during certain time-intervals was investigated using scanning electron microscope and Image Pro Plus program for image analysis. Obtained results of the investigation proved that creep can be useful method when type of refractory concrete is to be chosen for an application.",
publisher = "American Ceramic Society",
journal = "Mechanical Properties and Performance of Engineering Ceramics and Composites Vi",
title = "Determination of apparent porosity level of refractory concrete using ultrasonic pulse velocity technique and image analysis",
pages = "161-151",
number = "2",
volume = "32",
url = "https://hdl.handle.net/21.15107/rcub_rims_148"
}

Terzić, A., Pavlović, L.,& Mitić, V.. (2011). Determination of apparent porosity level of refractory concrete using ultrasonic pulse velocity technique and image analysis. in Mechanical Properties and Performance of Engineering Ceramics and Composites Vi
American Ceramic Society., 32(2), 151-161.
https://hdl.handle.net/21.15107/rcub_rims_148

Terzić A, Pavlović L, Mitić V. Determination of apparent porosity level of refractory concrete using ultrasonic pulse velocity technique and image analysis. in Mechanical Properties and Performance of Engineering Ceramics and Composites Vi. 2011;32(2):151-161.
https://hdl.handle.net/21.15107/rcub_rims_148 .

Terzić, Anja, Pavlović, Ljubica, Mitić, Vojislav, "Determination of apparent porosity level of refractory concrete using ultrasonic pulse velocity technique and image analysis" in Mechanical Properties and Performance of Engineering Ceramics and Composites Vi, 32, no. 2 (2011):151-161,
https://hdl.handle.net/21.15107/rcub_rims_148 .