Page 154 - New Trends in Green Construction

Advanced Construction Materials and Technologies
3. Results and conclusions
In this first stage, the dispersions were prepared, choosing the best nanoparticles by composition and smallest diameter of particle. For the TiO2, nanotitania rich in Anatase phase with Planetary mill activation was selected; for the alumina, commercial alumina with attritor mill activation was used; and for the silica, powder calcined with attritor mill activation was synthetized.
Then, dispersions with different percentages of powder were prepared and the Z-potential test was carried out tomake sure that the diameter of the particle were the correct and the dispersions were stable. The chosen dispersions are shown in the Table 1:
Material
d [nm]
ξ [mV]
AL2O3 - 0,05 % AL2O3 - 0,1 %
TiO2 (S-4) - 0,01 %
TiO2 (S-4) - 0,1 %
SiO2 - 0,05 % SiO2 - 0,1 % SiO2 - 0,05 % + D SiO2 - 0,1 % + D
72,28 ± 11,1 42,84 ± 6,58 111,4 - 63,5% 227 - 36,5 % 109,4 - 63 % 241,9 - 37 % 261,6
245 280,5 238,5
-37,3 -29,5
-54,2
-56,1
-36,5 -39 -40,6 -42,6
Table 1. Z-potential test and diameter of the particle in the dispersion.
The next step will be applying the dispersions on the concrete samples and evaluate their effectiveness and durability.
4. Acknowledgment
COST Action CA15202 for the STSMs at University of Novi sad, Faculty of Technology, and Ss Cyril and Methodius University in Skopje, Faculty of Technology and Metallurgy
5. References
Sánchez M., Alonso M.C., González R. (2014) Preliminary attempt of hardened mortar sealing by colloidal nanosilica migration. Construction and Building Materials 66, pp. 306-12
Franzoni E., Pigino B., Pistolesi C. (2013) Ethyl silicate for surface protection of concrete: Performance in comparison with other inorganic surface treatments. Cement & Concrete Composites 44, pp. 69–76
Xiaoying P., Zhenguo S., Caijun S. (2017) A review on concrete surface treatment Part I: Types and mechanisms. Construction and Building Materials 132, pp. 578–590
Xiaoying P., Zhenguo S., Caijun S. (2017)A review on surface treatment for concrete – Part 2: Performance. Construction and Building Materials 133, pp. 81–90
Sánchez M., Faria P., Ferrara L. (2018) External treatments for the preventive repair of existing constructions: A review. Construction and Building Materials 193, pp. 435–52
154