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E. Janowska-Renkas and D. Matyjaszczyk
1 Introduction
Modification of the concrete started in the 90s of the twentieth century included
the following aspects: structural, functional and ecological ones. One of examples
for structural modifications are concretes with increased durability. These concretes,
unlike the ordinary concrete, have a dense microstructure and a low water-to-cement
ratio (w/c ~ 0.2) [1–3]. The most important properties of the concrete currently
produced are e.g. very good workability of the fresh concrete, high compressive
strength after 28 days—above 60 MPa, water-proof properties, frost resistance, resistance to abrasion and impact of environmental conditions, thermal inertia, soundproof properties, fire and water protection. Furthermore, it is the ecological material
and thus it is not hazardous to human health [1–4].
Achievement of properties mentioned above was possible thanks to modification
of the concrete composition, which nowadays is a multi-constituent composite material composed of cement, aggregate, water, chemical admixtures, including effective
superplasticizers, as well as the waste substances in a form of mineral additives that
show pozzolanic and hydraulic properties, such as e.g.: silica fume, fly ash or blast
furnace slag [1–3].
Since the beginning of the twenty-first century, a quick development of nanomaterials application in the concrete technology has been observed. As research [4–7]
showed also in case of the concrete, a beneficial way to increase its utility parameters
is to introduce nanoparticles to the cement or the concrete. Until now, the impact of
such nanoparticles as the oxides of: TiO 2 , Fe 2 O 3 , SiO 2 , Al 2 O 3 as well as nanoparticles of silver and copper have been best tested. And thus e.g. TiO 2 in the nanoform has
the impact on achievement of self-cleaning properties by the concrete, and introduction of Ag and Cu nanoparticles—of bactericidal properties. Whereas introduction
of nano—Fe 2 O 3 or SiO 2 causes the increase of the flexural and compressive strength
of cement materials [4, 8–11].
Studies of many authors demonstrated that introduction of a small amount of ZnO,
Cr 2 O 3 nanoparticles, from 0.5 to 2% by mass, causes only a slight improvement
of mechanical properties; the growth in strength was generally from 5 to 20% [9,
12], a slightly higher in case of nano SiO 2 and Al 2 O 3 introduction—from 16 to
45% [9, 13], whereas introduction of nano ZnO and TiO 2 even caused deterioration
of the compressive strength by as many about 30% [14, 15], and in the case of nano
TiO 2 even the stop of hydratation [15]. Nano-modification in this case is based on
introduction of the following nano-oxides to the concrete mixture: iron, aluminium,
titanium, silica oxides or even carbon nanotubes or nanosilica with particle size
approximately 5 nm [16–21].
Spectacular researches are attributable to Iranian engineers, an example of which
is a Persian nanoconcrete proposed by professor Nazari [19]. They demonstrate that
inclusion of nanoparticles of iron, aluminium, zirconium, titanium or copper nanooxides to the ultra-high performance concrete allows to increase its impact strength,
which is 4 times higher than the impact strength of Ductal concrete, which makes it
more attractive for military applications: to build fortifications and bunkers.
E. Janowska-Renkas and D. Matyjaszczyk
1 Introduction
Modification of the concrete started in the 90s of the twentieth century included
the following aspects: structural, functional and ecological ones. One of examples
for structural modifications are concretes with increased durability. These concretes,
unlike the ordinary concrete, have a dense microstructure and a low water-to-cement
ratio (w/c ~ 0.2) [1–3]. The most important properties of the concrete currently
produced are e.g. very good workability of the fresh concrete, high compressive
strength after 28 days—above 60 MPa, water-proof properties, frost resistance, resistance to abrasion and impact of environmental conditions, thermal inertia, soundproof properties, fire and water protection. Furthermore, it is the ecological material
and thus it is not hazardous to human health [1–4].
Achievement of properties mentioned above was possible thanks to modification
of the concrete composition, which nowadays is a multi-constituent composite material composed of cement, aggregate, water, chemical admixtures, including effective
superplasticizers, as well as the waste substances in a form of mineral additives that
show pozzolanic and hydraulic properties, such as e.g.: silica fume, fly ash or blast
furnace slag [1–3].
Since the beginning of the twenty-first century, a quick development of nanomaterials application in the concrete technology has been observed. As research [4–7]
showed also in case of the concrete, a beneficial way to increase its utility parameters
is to introduce nanoparticles to the cement or the concrete. Until now, the impact of
such nanoparticles as the oxides of: TiO 2 , Fe 2 O 3 , SiO 2 , Al 2 O 3 as well as nanoparticles of silver and copper have been best tested. And thus e.g. TiO 2 in the nanoform has
the impact on achievement of self-cleaning properties by the concrete, and introduction of Ag and Cu nanoparticles—of bactericidal properties. Whereas introduction
of nano—Fe 2 O 3 or SiO 2 causes the increase of the flexural and compressive strength
of cement materials [4, 8–11].
Studies of many authors demonstrated that introduction of a small amount of ZnO,
Cr 2 O 3 nanoparticles, from 0.5 to 2% by mass, causes only a slight improvement
of mechanical properties; the growth in strength was generally from 5 to 20% [9,
12], a slightly higher in case of nano SiO 2 and Al 2 O 3 introduction—from 16 to
45% [9, 13], whereas introduction of nano ZnO and TiO 2 even caused deterioration
of the compressive strength by as many about 30% [14, 15], and in the case of nano
TiO 2 even the stop of hydratation [15]. Nano-modification in this case is based on
introduction of the following nano-oxides to the concrete mixture: iron, aluminium,
titanium, silica oxides or even carbon nanotubes or nanosilica with particle size
approximately 5 nm [16–21].
Spectacular researches are attributable to Iranian engineers, an example of which
is a Persian nanoconcrete proposed by professor Nazari [19]. They demonstrate that
inclusion of nanoparticles of iron, aluminium, zirconium, titanium or copper nanooxides to the ultra-high performance concrete allows to increase its impact strength,
which is 4 times higher than the impact strength of Ductal concrete, which makes it
more attractive for military applications: to build fortifications and bunkers.