Effect of micro-sized silica aerogel on the properties of lightweight cement composite

Research Development in Silica Aerogel Incorporated Cementitious Composites—A Review

“…According to the literature data presented, the introduction of silica aerogel in the form of granulate into the cement matrix instead of a traditional aggregate is associated with a simultaneous drastic decrease in compressive strength. Some researchers indicate that the reason for this is the lack of adhesion between the aerogel and cement paste [ 67 , 68 , 76 , 89 , 90 ]. Figure 6 shows the transition zone between aerogel and cement binder and reveals the aforementioned air gap between the two materials.…”

“…In turn, Shah et al clearly indicate that an important issue in the future will be to increase the wettability of the silica aerogel so that good bonding with the cementitious binder can be achieved. This should, accordingly, lead to good mechanical performance and reduced absorbability of the composite [ 89 ]. The work of Al Zaidi et al exemplifies such a solution [ 72 ].…”

“…This is due to the increased porosity of the cement composites, which significantly depends on the amount of silica aerogel introduced into the structure. The effect of the porosity of aerogel cement composites on their physicomechanical parameters, mainly their compressive strength and thermal conductivity coefficient, has been studied by many researchers [ 68 , 89 , 104 , 105 , 106 ]. According to Shah et al, silica aerogel, in introducing a high degree of hydrophobicity into the structure of the cement matrix, contributes to an increase in the number of macropores, which in turn causes a decrease in the density of the material by 35% and compressive strength by 76% while enhancing the absorbability and water absorption rate of the composite [ 89 ].…”

“…The effect of the porosity of aerogel cement composites on their physicomechanical parameters, mainly their compressive strength and thermal conductivity coefficient, has been studied by many researchers [ 68 , 89 , 104 , 105 , 106 ]. According to Shah et al, silica aerogel, in introducing a high degree of hydrophobicity into the structure of the cement matrix, contributes to an increase in the number of macropores, which in turn causes a decrease in the density of the material by 35% and compressive strength by 76% while enhancing the absorbability and water absorption rate of the composite [ 89 ]. Changes in the porosity of lightweight cement composites as a function of the addition of silica aerogel and air-entraining admixture and aluminum powder was also investigated by Strzałkowski and Garbalińska [ 105 ].…”

“… SEM images for cementitious composites with silica aerogel with visible gap between cement paste and silica aerogel. Reproduced with permission [ 67 , 68 , 89 , 90 ], respectively, for ( a – c ), and ( d ). Copyright 2014, 2015, 2021, Elsevier.…”