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Przeglądaj Wydział Budownictwa i Inżynierii Środowiska wg Autor "Cendrowski, Krzysztof"
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Pozycja Open Access Enhancing the Fresh and Early Age Performances of Portland Cement Pastes via Sol-Gel Silica Coating of Metal Oxides (Bi2O3 and Gd2O3)(MDPI, 2023) Cendrowski, Krzysztof; Federowicz, Karol; Techman, Mateusz; Chougan, Mehdi; Kędzierski, Tomasz; Sanytsky, Myroslav; Mijowska, Ewa; Sikora, Paweł; West Pomeranian University of Technology in Szczecin. Faculty of Civil and Environmental Engineering, Poland; West Pomeranian University of Technology in Szczecin. Faculty of Civil and Environmental Engineering, Poland; West Pomeranian University of Technology in Szczecin. Faculty of Civil and Environmental Engineering, Poland; Brunel University London. Department of Civil and Environmental Engineering,UK; West Pomeranian University of Technology. Faculty of Chemical Technology and Engineering. Poland; Lviv Polytechnic National University. Department of Building Production; West Pomeranian University of Technology. Faculty of Chemical Technology and Engineering,; West Pomeranian University of Technology in Szczecin. Faculty of Civil and Environmental Engineering, PolandIncorporating metal oxide nanoparticles into cement-based composites delays the hydration process and strength gain of cementitious composites. This study presents an approach toward improving the performance of bismuth oxide (Bi2O3) and gadolinium oxide (Gd2O3) particles in cementitious systems by synthesizing core–shell structures via a sol-gel process. Two types of silica coatings on cementitious pastes with 5% and 10% substitution levels were proposed. The rheology, hydration, and mechanical properties of the pastes were analyzed to determine the relationship between the coating type and nanoparticle concentration. The results indicate that despite the significant disparities in the performance of the resulting material, both methods are appropriate for cement technology applications. Bi2O3’s silica coatings accelerate the hydration process, leading to early strength development in the cement paste. However, due to the coarse particle size of Gd2O3, silica coatings exhibited negligible effects on the early age characteristics of cement pastes.Pozycja Open Access Functional Bi2O3/Gd2O3 Silica-Coated Structures for Improvement of Early Age and Radiation Shielding Performance of Cement Paste(MDPI, 2024-01-12) Cendrowski, Krzysztof; Federowicz, Karol; Techman, Mateusz; Chougan, Mehdi; El-Khayatt, Ahmed M.; Saudi, H.A.; Kędzierski, Tomasz; Mijowska, Ewa; Strzałkowski, Jarosław; Sibera, Daniel; Abd Elrahman, Mohamed; Sikora, Pawel; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental Engineering; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental Engineering; Imam Mohammad Ibn Saud Islamic University, Department of Physics, College of Science; Brunel University London, Department of Civil and Environmental Engineering; Atomic Energy Authority, Cairo, Nuclear Research Centre, Reactor Physics Department; Al-Azhar University, Women Branch, Nasr City Faculty of Science. Department of Physics,; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Nanomaterials Physicochemistry.; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental Engineering; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental Engineering; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Nanomaterials Physicochemistry.; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental Engineering; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental Engineering; Mansoura University, Mansoura City. Structural Engineering Department; West Pomeranian University of Technology in Szczecin, Faculty of Civil and Environmental EngineeringThis study presents a new approach towards the production of sol-gel silica-coated Bi2O3/Gd2O3 cement additives towards the improvement of early mechanical performance and radiation attenuation. Two types of silica coatings, which varied in synthesis method and morphology, were used to coat Bi2O3/Gd2O3 structures and evaluated as a cement filler in Portland cement pastes. Isothermal calorimetry studies and early strength evaluations confirmed that both proposed coating types can overcome retarded cement hydration process, attributed to Bi2O3 presence, resulting in improved one day compressive strength by 300% and 251% (depending on coating method) when compared to paste containing pristine Bi2O3 and Gd2O3 particles. Moreover, depending on the type of chosen coating type, various rheological performances of cement pastes can be achieved. Thanks to the proposed combination of materials, both gamma-rays and slow neutron attenuation in cement pastes can be simultaneously improved. The introduction of silica coating resulted in an increment of the gamma-ray and neutron shielding thanks to the increased probability of radiation interaction. Along with the positive early age effects of the synthesized structures, the 28 day mechanical performance of cement pastes was not suppressed, and was found to be comparable to that of the control specimen. As an outcome, silica-coated structures can be successfully used in radiation-shielding cement-based composites, e.g. with demanding early age performances.