SCC modification by use of amorphous nano-silica

Abstract

a b s t r a c tIn this study two different types of nano-silica (nS) were applied in self-compacting concrete (SCC), both having similar particle size distributions (PSD), but produced through two different processes: fumed powder silica and precipitated silica in colloidal suspension. The influence of nano-silica on SCC was investigated with respect to the properties of concrete in fresh (workability) and hardened state (mechanical properties and durability). Additionally, the densification of the microstructure of the hardened concrete was verified by SEM and EDS analyses. The obtained results demonstrate that nano-silica efficiently used in SCC can improve its mechanical properties and durability. Considering the reactivity of the two applied nano-silicas, the colloidal type showed a higher reactivity at early age, which influenced the final SCC properties.

Static properties and impact resistance of a green Ultra-High Performance Hybrid Fibre Reinforced Concrete (UHPHFRC): Experiments and modeling

“…The modified Andreasen and Andersen packing model has already been successfully employed in optimization algorithms for the design of normal density concrete [46,49,50,76,77] and lightweight concrete [47,48]. Different types of con- [49].…”

Study of durability of Portland cement mortars blended with silica nanoparticles

“…Other interesting investigations include those by MinHong et al [1], Deyu Kong et al [22], Said et al [8], and Mostafa et al [23], which analyze the resistance to chloride-ion penetration made on concrete of Portland cement blended with NS, and the work of Berra et al [24], which studied the use of NS for preventing expansive alkali-silica reaction in concrete. Quercia et al [25], which found that some durability indicators like conductivity, chlorine migration and diffusion coefficients, and freeze-thaw resistance were significantly improved in self-compacting concrete (SCC) with addition of NS. Ibrahim Rahel et al…”

Effect of Adding Silicon Carbide and Titanium Carbide Nanoparticles on the Performance of the Cement Pastes

“…It is also depicted from Fig. 27 that the concentration of the CH was higher than the C-S-H gel concentration, and the CH hydrate needles covered a large area in the control cement pastes specimens [29]. Figures 28 and 29 show SEM of the cement pastes samples with (5% SiC and 5% TiC) nanoparticles, respectively at curing time 28 days that resulted in the highest mechanical properties than the other specimens having different nanoparticles percentages.…”

“…The improvements of mechanical properties may be related to the high activity of many nanoparticles. The nanomaterial can consume "calcium hydroxide crystals, fill pores to increase the strength, reduce the size of the crystals at the interface zone, transmute the calcium hydroxide feeble crystals to the C-S-H crystals, and improve the interface zone and the cement paste structures" [29,30].…”