TY  - CONF
AU  - Ilić, Biljana
AU  - Mitrović, Aleksandra
AU  - Radonjanin, Vlastimir
AU  - Malešev, Mirjana
AU  - Zdujić, Miodrag
PY  - 2018
UR  - https://dais.sanu.ac.rs/123456789/2376
AB  - Kaolin from a Serbian deposit, having a high content of mica and quartz, disordered kaolinite and a high specific surface area, was used to prepare metakaolin (MK). The calcination at temperatures of 700 °C or 750 °C for 30 to 180 min resulted in MK having high pozzolanic activity, but also significant aglomeration of particles. In order to disperse aglomerates, MK was milled, which resulted in increased pozzolanic activity and reduced particle size. The effects of MK and additionally milled metakaolin (MKmill) on the composite strengths and microstructure of the pastes were compared. We prepared and investigated composites in which ordinary Portland cement (OPC) was replaced with 10% to 50% of MK or MKmill, as well as the representative samples of paste for determination of microstructure.

Compressive strengths higher than the control were obtained for composites having up to 30% of MK and up to 40% of MKmill, respectively. Increase of composite strengths with MKmill was more pronounced at lower cement replacement levels (10% and 20%).

Compressive strength of composites containing agglomerated MK were satisfactory, which suggests that milling of MK, as well as purification of kaolin, may not be necessary.
PB  - Dordrecht : Springer
C3  - Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete
T1  - Compressive Strength Improvements of Cement-Based Composites Achieved with Additional Milling of Metakaolin
SP  - 212
EP  - 218
DO  - 10.1007/978-94-024-1207-9_34
UR  - https://hdl.handle.net/21.15107/rcub_dais_2376
ER  - 

@conference{
author = "Ilić, Biljana and Mitrović, Aleksandra and Radonjanin, Vlastimir and Malešev, Mirjana and Zdujić, Miodrag",
year = "2018",
abstract = "Kaolin from a Serbian deposit, having a high content of mica and quartz, disordered kaolinite and a high specific surface area, was used to prepare metakaolin (MK). The calcination at temperatures of 700 °C or 750 °C for 30 to 180 min resulted in MK having high pozzolanic activity, but also significant aglomeration of particles. In order to disperse aglomerates, MK was milled, which resulted in increased pozzolanic activity and reduced particle size. The effects of MK and additionally milled metakaolin (MKmill) on the composite strengths and microstructure of the pastes were compared. We prepared and investigated composites in which ordinary Portland cement (OPC) was replaced with 10% to 50% of MK or MKmill, as well as the representative samples of paste for determination of microstructure.

Compressive strengths higher than the control were obtained for composites having up to 30% of MK and up to 40% of MKmill, respectively. Increase of composite strengths with MKmill was more pronounced at lower cement replacement levels (10% and 20%).

Compressive strength of composites containing agglomerated MK were satisfactory, which suggests that milling of MK, as well as purification of kaolin, may not be necessary.",
publisher = "Dordrecht : Springer",
journal = "Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete",
title = "Compressive Strength Improvements of Cement-Based Composites Achieved with Additional Milling of Metakaolin",
pages = "212-218",
doi = "10.1007/978-94-024-1207-9_34",
url = "https://hdl.handle.net/21.15107/rcub_dais_2376"
}

Ilić, B., Mitrović, A., Radonjanin, V., Malešev, M.,& Zdujić, M.. (2018). Compressive Strength Improvements of Cement-Based Composites Achieved with Additional Milling of Metakaolin. in Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete
Dordrecht : Springer., 212-218.
https://doi.org/10.1007/978-94-024-1207-9_34
https://hdl.handle.net/21.15107/rcub_dais_2376

Ilić B, Mitrović A, Radonjanin V, Malešev M, Zdujić M. Compressive Strength Improvements of Cement-Based Composites Achieved with Additional Milling of Metakaolin. in Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete. 2018;:212-218.
doi:10.1007/978-94-024-1207-9_34
https://hdl.handle.net/21.15107/rcub_dais_2376 .

Ilić, Biljana, Mitrović, Aleksandra, Radonjanin, Vlastimir, Malešev, Mirjana, Zdujić, Miodrag, "Compressive Strength Improvements of Cement-Based Composites Achieved with Additional Milling of Metakaolin" in Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete (2018):212-218,
https://doi.org/10.1007/978-94-024-1207-9_34 .,
https://hdl.handle.net/21.15107/rcub_dais_2376 .

TY  - CONF
AU  - Ilić, Biljana
AU  - Radonjanin, Vlastimir
AU  - Malešev, Mirjana
AU  - Zdujić, Miodrag
AU  - Mitrović, Aleksandra
PY  - 2018
UR  - https://dais.sanu.ac.rs/123456789/2375
AB  - Environmental concerns and sustainable development require increased replacement of cement. Most of previous studies have shown that the compressive strength of cement-based composites is maximized with a 20% content of metakaolin. We investigated composites prepared by replacing ordinary Portland Cement (OPC) with 30 to 50% of metakaolin (MK) and addition of appropriate amount of hydrated lime, which were ordinary cured for 2, 28 or 90 days. Hydration products and microstructure of the pastes were determined by X-ray diffraction (XRD), differential thermal analysis/thermal gravimetry (DTA/TG) and mercury intrusion porosimetry (MIP). MK was produced by calcination of kaolin from a Serbian deposit, which contained a high level of impurities.

Replacement of OPC with 30% of MK achieved 28 days compressive strength equivalent to that of the control mix. Higher replacement levels, 40% and 50%, combined with the addition of hydrated lime, achieved satisfactory relative strengths of 94% and 87%, respectively. The positive contribution was particularly pronounced after 90 days for a composite containing 50% of MK. The results clearly showed a possibility of obtaining composites having acceptable compressive strength with reduced cement content in accordance with environmental and sustained development requirements.
PB  - Dordrecht : Springer
C3  - Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete
T1  - Properties of the cement-based composites with high content of metakaolin
DO  - 10.1007/978-94-024-1207-9_35
UR  - https://hdl.handle.net/21.15107/rcub_dais_2375
ER  - 

@conference{
author = "Ilić, Biljana and Radonjanin, Vlastimir and Malešev, Mirjana and Zdujić, Miodrag and Mitrović, Aleksandra",
year = "2018",
abstract = "Environmental concerns and sustainable development require increased replacement of cement. Most of previous studies have shown that the compressive strength of cement-based composites is maximized with a 20% content of metakaolin. We investigated composites prepared by replacing ordinary Portland Cement (OPC) with 30 to 50% of metakaolin (MK) and addition of appropriate amount of hydrated lime, which were ordinary cured for 2, 28 or 90 days. Hydration products and microstructure of the pastes were determined by X-ray diffraction (XRD), differential thermal analysis/thermal gravimetry (DTA/TG) and mercury intrusion porosimetry (MIP). MK was produced by calcination of kaolin from a Serbian deposit, which contained a high level of impurities.

Replacement of OPC with 30% of MK achieved 28 days compressive strength equivalent to that of the control mix. Higher replacement levels, 40% and 50%, combined with the addition of hydrated lime, achieved satisfactory relative strengths of 94% and 87%, respectively. The positive contribution was particularly pronounced after 90 days for a composite containing 50% of MK. The results clearly showed a possibility of obtaining composites having acceptable compressive strength with reduced cement content in accordance with environmental and sustained development requirements.",
publisher = "Dordrecht : Springer",
journal = "Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete",
title = "Properties of the cement-based composites with high content of metakaolin",
doi = "10.1007/978-94-024-1207-9_35",
url = "https://hdl.handle.net/21.15107/rcub_dais_2375"
}

Ilić, B., Radonjanin, V., Malešev, M., Zdujić, M.,& Mitrović, A.. (2018). Properties of the cement-based composites with high content of metakaolin. in Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete
Dordrecht : Springer..
https://doi.org/10.1007/978-94-024-1207-9_35
https://hdl.handle.net/21.15107/rcub_dais_2375

Ilić B, Radonjanin V, Malešev M, Zdujić M, Mitrović A. Properties of the cement-based composites with high content of metakaolin. in Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete. 2018;.
doi:10.1007/978-94-024-1207-9_35
https://hdl.handle.net/21.15107/rcub_dais_2375 .

Ilić, Biljana, Radonjanin, Vlastimir, Malešev, Mirjana, Zdujić, Miodrag, Mitrović, Aleksandra, "Properties of the cement-based composites with high content of metakaolin" in Calcined Clays for Sustainable Concrete: Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete (2018),
https://doi.org/10.1007/978-94-024-1207-9_35 .,
https://hdl.handle.net/21.15107/rcub_dais_2375 .

TY  - JOUR
AU  - Ilić, Biljana
AU  - Radonjanin, Vlastimir
AU  - Malešev, Mirjana
AU  - Zdujić, Miodrag
AU  - Mitrović, Aleksandra
PY  - 2017
UR  - https://dais.sanu.ac.rs/123456789/2341
AB  - The effects of thermally (MK) or mechanically activated kaolin (AK) on the compressive strength of mortars and microstructure of pastes were investigated. Mortar mixtures, in which 10%, 20% and 30% of ordinary Portland cement (OPC) was replaced by either MK or AK, were prepared (w/b of 0.5) and ordinary (age 2, 28 or 90 days) and autoclave cured. Hydration products were determined by X-ray diffraction (XRD) and differential thermal analysis/thermal gravimetry (DTA/TG) analysis, while microstructure was investigated by mercury intrusion porosimetry (MIP).

MK substitution increases the compressive strength of ordinary-cured mortars, as a result of the higher content of reactive silica that caused more pronounced pozzolanic reaction, as well as by effective refinement of their pore structure. Positive effects on the compressive strength could be achieved up to 30% substitution of OPC by MK. The OPC substitution by AK resulted in lower strengths of ordinary-cured mortars, compared to both MK mortars and reference. Higher specific surface area and finer particles of AK were insufficient to compensate, through filler effect, lower pozzolanic reaction and additional negative influence of the kaolinite presence. The highest compressive strength was obtained for mortar with 10% of AK (relative strength of 94%).

In comparison to the reference, autoclaved MK and AK mortars, exhibited lower compressive strength, as a consequence of increasing the hydrogarnet formation, instead of tobermorite. The highest strength was achieved for mortar with 10% of AK.
PB  - Elsevier
T2  - Construction and Building Materials
T1  - Study on the addition effect of metakaolin and mechanically activated kaolin on cement strength and microstructure under different curing conditions
SP  - 243
EP  - 252
VL  - 133
DO  - 10.1016/j.conbuildmat.2016.12.068
UR  - https://hdl.handle.net/21.15107/rcub_dais_2341
ER  - 

@article{
author = "Ilić, Biljana and Radonjanin, Vlastimir and Malešev, Mirjana and Zdujić, Miodrag and Mitrović, Aleksandra",
year = "2017",
abstract = "The effects of thermally (MK) or mechanically activated kaolin (AK) on the compressive strength of mortars and microstructure of pastes were investigated. Mortar mixtures, in which 10%, 20% and 30% of ordinary Portland cement (OPC) was replaced by either MK or AK, were prepared (w/b of 0.5) and ordinary (age 2, 28 or 90 days) and autoclave cured. Hydration products were determined by X-ray diffraction (XRD) and differential thermal analysis/thermal gravimetry (DTA/TG) analysis, while microstructure was investigated by mercury intrusion porosimetry (MIP).

MK substitution increases the compressive strength of ordinary-cured mortars, as a result of the higher content of reactive silica that caused more pronounced pozzolanic reaction, as well as by effective refinement of their pore structure. Positive effects on the compressive strength could be achieved up to 30% substitution of OPC by MK. The OPC substitution by AK resulted in lower strengths of ordinary-cured mortars, compared to both MK mortars and reference. Higher specific surface area and finer particles of AK were insufficient to compensate, through filler effect, lower pozzolanic reaction and additional negative influence of the kaolinite presence. The highest compressive strength was obtained for mortar with 10% of AK (relative strength of 94%).

In comparison to the reference, autoclaved MK and AK mortars, exhibited lower compressive strength, as a consequence of increasing the hydrogarnet formation, instead of tobermorite. The highest strength was achieved for mortar with 10% of AK.",
publisher = "Elsevier",
journal = "Construction and Building Materials",
title = "Study on the addition effect of metakaolin and mechanically activated kaolin on cement strength and microstructure under different curing conditions",
pages = "243-252",
volume = "133",
doi = "10.1016/j.conbuildmat.2016.12.068",
url = "https://hdl.handle.net/21.15107/rcub_dais_2341"
}

Ilić, B., Radonjanin, V., Malešev, M., Zdujić, M.,& Mitrović, A.. (2017). Study on the addition effect of metakaolin and mechanically activated kaolin on cement strength and microstructure under different curing conditions. in Construction and Building Materials
Elsevier., 133, 243-252.
https://doi.org/10.1016/j.conbuildmat.2016.12.068
https://hdl.handle.net/21.15107/rcub_dais_2341

Ilić B, Radonjanin V, Malešev M, Zdujić M, Mitrović A. Study on the addition effect of metakaolin and mechanically activated kaolin on cement strength and microstructure under different curing conditions. in Construction and Building Materials. 2017;133:243-252.
doi:10.1016/j.conbuildmat.2016.12.068
https://hdl.handle.net/21.15107/rcub_dais_2341 .

Ilić, Biljana, Radonjanin, Vlastimir, Malešev, Mirjana, Zdujić, Miodrag, Mitrović, Aleksandra, "Study on the addition effect of metakaolin and mechanically activated kaolin on cement strength and microstructure under different curing conditions" in Construction and Building Materials, 133 (2017):243-252,
https://doi.org/10.1016/j.conbuildmat.2016.12.068 .,
https://hdl.handle.net/21.15107/rcub_dais_2341 .

TY  - JOUR
AU  - Ilić, Biljana
AU  - Radonjanin, Vlastimir
AU  - Malešev, Mirjana
AU  - Zdujić, Miodrag
AU  - Mitrović, Aleksandra
PY  - 2016
UR  - https://dais.sanu.ac.rs/123456789/15976
AB  - Kaolin from a Serbian deposit, characterized by high content of impurities, such as mica and quartz, disordered kaolinite and high specific surface area, was subjected to thermal and mechanical activation on a large scale. Activations were carried out with a goal to investigate the effects of applied methods on the chemical, structural and morphological changes that occurred in the kaolin, and their influence on the pozzolanic activity. The changes were monitored using XRD, FTIR, TG/DTA, PSD, BET and SEM analyses. Pozzolanic activity was evaluated by determination of the 7-day compressive strength conducted on the lime mortars.

The results showed that mechanical activation by milling the kaolin for 20 h in the conventional horizontal ball mill was competitive for obtaining pozzolana as thermal activation. Pozzolanic activity of thermally activated kaolin was mainly influenced by formation of metakaolin. Combined effects (such as significant specific surface area increase, as well as partial kaolinite and complete mica phase amorphization) were dominant in pozzolanic activity of mechanically activated kaolin.
PB  - Elsevier
T2  - Applied Clay Science
T1  - Effects of mechanical and thermal activation on pozzolanic activity of kaolin containing mica
SP  - 173
EP  - 181
VL  - 123
DO  - 10.1016/j.clay.2016.01.029
UR  - https://hdl.handle.net/21.15107/rcub_dais_15976
ER  - 

@article{
author = "Ilić, Biljana and Radonjanin, Vlastimir and Malešev, Mirjana and Zdujić, Miodrag and Mitrović, Aleksandra",
year = "2016",
abstract = "Kaolin from a Serbian deposit, characterized by high content of impurities, such as mica and quartz, disordered kaolinite and high specific surface area, was subjected to thermal and mechanical activation on a large scale. Activations were carried out with a goal to investigate the effects of applied methods on the chemical, structural and morphological changes that occurred in the kaolin, and their influence on the pozzolanic activity. The changes were monitored using XRD, FTIR, TG/DTA, PSD, BET and SEM analyses. Pozzolanic activity was evaluated by determination of the 7-day compressive strength conducted on the lime mortars.

The results showed that mechanical activation by milling the kaolin for 20 h in the conventional horizontal ball mill was competitive for obtaining pozzolana as thermal activation. Pozzolanic activity of thermally activated kaolin was mainly influenced by formation of metakaolin. Combined effects (such as significant specific surface area increase, as well as partial kaolinite and complete mica phase amorphization) were dominant in pozzolanic activity of mechanically activated kaolin.",
publisher = "Elsevier",
journal = "Applied Clay Science",
title = "Effects of mechanical and thermal activation on pozzolanic activity of kaolin containing mica",
pages = "173-181",
volume = "123",
doi = "10.1016/j.clay.2016.01.029",
url = "https://hdl.handle.net/21.15107/rcub_dais_15976"
}

Ilić, B., Radonjanin, V., Malešev, M., Zdujić, M.,& Mitrović, A.. (2016). Effects of mechanical and thermal activation on pozzolanic activity of kaolin containing mica. in Applied Clay Science
Elsevier., 123, 173-181.
https://doi.org/10.1016/j.clay.2016.01.029
https://hdl.handle.net/21.15107/rcub_dais_15976

Ilić B, Radonjanin V, Malešev M, Zdujić M, Mitrović A. Effects of mechanical and thermal activation on pozzolanic activity of kaolin containing mica. in Applied Clay Science. 2016;123:173-181.
doi:10.1016/j.clay.2016.01.029
https://hdl.handle.net/21.15107/rcub_dais_15976 .

Ilić, Biljana, Radonjanin, Vlastimir, Malešev, Mirjana, Zdujić, Miodrag, Mitrović, Aleksandra, "Effects of mechanical and thermal activation on pozzolanic activity of kaolin containing mica" in Applied Clay Science, 123 (2016):173-181,
https://doi.org/10.1016/j.clay.2016.01.029 .,
https://hdl.handle.net/21.15107/rcub_dais_15976 .