Effect of Nanosilica Particle Size on the Water Permeability, Abrasion Resistance, Drying Shrinkage, and Repair Work Properties of Cement Mortar Containing Nano-SiO₂

Table 1

Chemical composition of ordinary Portland cement, silica fume, and nanosilica.

Item	Chemical composition (%)
	OPC	Silica fume	AEROSIL 200	AEROSIL 90	AEROSIL OX 50
SiO2	22	88.3	99.8	99.8	99.8
Al2O3	6.6	1.17	—	—	—
Fe2O3	2.8	4.76	—	—	—
CaO	60.1	0.48	—	—	—
MgO	3.3	2.14	—	—	—
SO3	2.1	1.05	—	—	—
LOI	2.6	2.1	0.2	0.2	0.2
Surface area (m^2/g)	0.38	20	200	90	50
Mean particle size (nm)	15,000	100	12	20	40

OPC: ordinary Portland cement.
AEROSIL 200: nanosilica with particle size of 12 nm.
AEROSIL 90: nanosilica with particle size of 20 nm.
AEROSIL OX 50: nanosilica with particle size of 40 nm.
LOI: loss on ignition.