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A. Kaleta-Jurowska et al.
aluminium oxides, which makes it the strongly pozzolanic additive after a longer
curing period. In consequence the concrete with this additives has better durability
[25].
Beneficial effects can be also achieved with various mineral additives applied
simultaneously. Tests presented in the paper [26] demonstrated that concretes made
with the use of fly ash and silica fume simultaneously reached the strength higher
by even 40%, compared to concretes with fly ash only. Tests show that application of these additives allows to improve workability of the concrete. Furthermore,
authors of [27] proved that it was more justified economically than control of concrete
consistency with the use of a superplasticizer.
Another waste material from industry is the fly ash coming from combustion in
fluidized bed boilers. However, the use of this material, is problematic, due to a high
content of calcium sulphate, which may cause delayed production of ettringite, and
in consequence destruction of the concrete. They are also heterogeneous, as their
chemical composition varies depending on a place of combustion and an origin of
the material being combusted [28].
Steel slag is an industrial waste from either the conversion of iron to steel in a
basic oxygen furnace or from melting scrap to make steel in an electric arc furnace.
Its composition is made of oxides such as CaO, MgO, SiO 2 , and FeO, which makes
it have binding properties and it is ideal for the use as the mineral additive to the
Portland cement. It shall be noted that the CO 2 emission during its production is
much lower than during production of the Portland cement clinker [29].
A very important feature of concrete made of cement with addition of the ground
granulated blast furnace slag is a fact that it emits much less heat than the concrete
made of the Portland cement [7]. Concrete made with the use of blast furnace slags
has a slower strength growth rate (compare to Portland cement based concrete), but
its final strength is higher. It also shows better durability regardless of its exposure.
It is due the fact that a microstructure of hardened binder is compacted and sealed. It
was also found that the use of the blast furnace slag as the mineral additive to cement
is more effective than its use as the aggregate, e.g. for subsoil stabilization [7].
It is estimated that the energy needed to grind the granulated blast furnace slag is
ten times lower than the energy needed for production of the Portland cement clinker
[7]. Due to the fact that production of the granulated blast furnace slag requires less
power consumption, concrete with this additive can be deemed as more environment
friendly [29].
Addition of granulated blast furnace slag to cement has also a beneficial effect
on workability of self-compacting concrete mixes. Tests presented in the paper [30]
show that the optimum quantity of slag to the cement mass is 20%. However, it
should be remembered, that concretes with this additive reach lower early strength.
Ground granulated blast furnace slag has a good influence on later strength, which
was demonstrated by tests after 56 and 90 days of curing.
This paper analyses the impact of grinding (fineness) of various types of mineral
additives: fly ash and ground granulated blast furnace slag on properties of mortars.
Physical properties of additives and impact on properties of fresh and hardened
A. Kaleta-Jurowska et al.
aluminium oxides, which makes it the strongly pozzolanic additive after a longer
curing period. In consequence the concrete with this additives has better durability
[25].
Beneficial effects can be also achieved with various mineral additives applied
simultaneously. Tests presented in the paper [26] demonstrated that concretes made
with the use of fly ash and silica fume simultaneously reached the strength higher
by even 40%, compared to concretes with fly ash only. Tests show that application of these additives allows to improve workability of the concrete. Furthermore,
authors of [27] proved that it was more justified economically than control of concrete
consistency with the use of a superplasticizer.
Another waste material from industry is the fly ash coming from combustion in
fluidized bed boilers. However, the use of this material, is problematic, due to a high
content of calcium sulphate, which may cause delayed production of ettringite, and
in consequence destruction of the concrete. They are also heterogeneous, as their
chemical composition varies depending on a place of combustion and an origin of
the material being combusted [28].
Steel slag is an industrial waste from either the conversion of iron to steel in a
basic oxygen furnace or from melting scrap to make steel in an electric arc furnace.
Its composition is made of oxides such as CaO, MgO, SiO 2 , and FeO, which makes
it have binding properties and it is ideal for the use as the mineral additive to the
Portland cement. It shall be noted that the CO 2 emission during its production is
much lower than during production of the Portland cement clinker [29].
A very important feature of concrete made of cement with addition of the ground
granulated blast furnace slag is a fact that it emits much less heat than the concrete
made of the Portland cement [7]. Concrete made with the use of blast furnace slags
has a slower strength growth rate (compare to Portland cement based concrete), but
its final strength is higher. It also shows better durability regardless of its exposure.
It is due the fact that a microstructure of hardened binder is compacted and sealed. It
was also found that the use of the blast furnace slag as the mineral additive to cement
is more effective than its use as the aggregate, e.g. for subsoil stabilization [7].
It is estimated that the energy needed to grind the granulated blast furnace slag is
ten times lower than the energy needed for production of the Portland cement clinker
[7]. Due to the fact that production of the granulated blast furnace slag requires less
power consumption, concrete with this additive can be deemed as more environment
friendly [29].
Addition of granulated blast furnace slag to cement has also a beneficial effect
on workability of self-compacting concrete mixes. Tests presented in the paper [30]
show that the optimum quantity of slag to the cement mass is 20%. However, it
should be remembered, that concretes with this additive reach lower early strength.
Ground granulated blast furnace slag has a good influence on later strength, which
was demonstrated by tests after 56 and 90 days of curing.
This paper analyses the impact of grinding (fineness) of various types of mineral
additives: fly ash and ground granulated blast furnace slag on properties of mortars.
Physical properties of additives and impact on properties of fresh and hardened