Browsing by Author "Le, Van Su"
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- ItemMechanical properties of geopolymer foam at high temperature(2020-01) Le, Van Su; Szczypinski, Michal M.; Hájková, Pavlína; Kovačič, Vladimír; Bakalova, Totka; Voleský, Lukáš; Hiep, Le Chi; Louda, PetrIn this work, geopolymer foam composites containing waste basalt fibre (10, 30, and 50%wt) were exposed to elevated temperatures of 200, 400, 600, 800 and 1000 degrees C. With an increase in high temperature, the geopolymer foams material exhibits a decrease in compressive strength and bending strength. When heated above 600 degrees C, geopolymer foams materials exhibit a significant reduction in mechanical properties. It shows clearly with the naked eye that surface cracks in case of samples containing 10% of basalt filler. However, when increasing fillers with basalt fibres up to 30% and 50%, the cracking of the sample surface is no longer visible to the naked eye. Especially when the temperature increases, the mechanical properties also increase without decreasing in the sample of 50% by weighing to the binder. The results show that reinforcing the geopolymer foams with basalt ground fibre improves the mechanical properties at high temperatures.
- ItemTHERMAL CONDUCTIVITY OF REINFORCED GEOPOLYMER FOAMS(UNIV CHEMISTRY & TECHNOLOGY, PRAGUE, TECHNICKA 5, PRAGUE 6, DEJVICE 166 28, CZECH REPUBLIC, 2019) Le, Van Su; Hájková, Pavlína; Kovačič, Vladimír; Bakalova, Totka; Voleský, Lukáš; Le, Chi Hiep; Seifert, Kevin Ceccon; Peres, Amanda Pereira; Louda, PetrReinforced geopolymer foams were studied in this work as potential building materials. It has been widely assumed that for a given thermal conductivity. [W center dot m(-1)center dot K-1], geopolymer foams can have a lighter density than other materials. The study sought to test this assumption by comparing the thermal conductivity between geopolymer foams. The thermal conductivity. was measured using an ISOMET 2014 device. In all the experiments, the geopolymer foams were obtained by adding aluminium powder and several combinations: silica fume and fine sand reinforced by short basalt fibres. Curing was carried out at room temperature and then in a furnace at 70 degrees C. After the curing process, the properties of the samples were tested at 7 and 28 days. The results show that the thermal conductivity, porosity, compressive strength, flexural strength and density for all of the tests ranged in the following values: 0.13 - 0.359 W center dot m(-1)center dot K-1; 41.8 - 62.5 %; 1.94 - 9 MPa; 0.96 - 2.93 MPa; 546 - 1028 kg center dot m(-3), respectively. It was proven that the filler in the geopolymer foams has a significant influence on the mechanical and physical properties of the tested samples.