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A. Kaleta-Jurowska et al.
often the waste materials are used as mineral additives to the cement (fly ash, silica
fume, ground-granulated blast-furnace slag) [3].
New solutions are still being searched for aiming at utilization of various types of
waste. The waste material of a great significance for the environment is tire rubber. As
data presented in [4] show the approximate weight of scrap-tires generated annually
only in the USA is estimated at 3.6 million tons. Tests showed that concretes with tire
rubber addition had much lower density, better ductility, better resistance to impacts
and better sound-proof properties. However, in case of concretes made of normal
cements, a drastic reduction of the compressive strength is observed [5].
A natural substitute of aggregate, which allows to get light concrete, are coconut
shells. There are also research studies conducted to replace sand and a part of cement
with calcareous tuffs. Results of research often demonstrate a beneficial impact of
individual waste materials on selected properties of the concrete made with their
application, however, the environment-friendly aspect of waste materials utilization
is emphasized [6].
To put it simply, production of the Portland cement includes the following phases:
grinding of raw materials, their firing in temp. 1500 °C and then grinding of clinker
with gypsum. It is estimated that energy needed to produce one ton of the cement is
about 4000 MJ. As most of mineral additives requires grinding only, their use saves
a lot of energy [7].
Production of Portland cement is one of the most important factors in CO 2 worldwide emission strategy [8]. Statistic data show that in 2017 China had the largest
production of the cement equal to 2.38 Bnt. The next places are taken by India
(423 Mt/yr), and then the USA (120.5 Mt/year) [9]. A high CO 2 emission is caused
by the fact, that the Portland cement clinker production requires combustion of solid
fuels (for calcination of limestone in high temperatures) [2]. Production of the clinker
also requires transport of raw materials and electricity supply to the cement plant.
Therefore it is estimated that the cement industry in total accounts for 8% of the
global emission of carbon dioxide [10, 11]. Reduction of these values is possible
due to utilization of mineral additives as substitutes for the clinker [12] or through
application of waste materials such as phosphogypsum and waste limestone sludge,
waste stone sludge, iron oxide sludge, and spent catalyst as raw materials in the
production of the so-called eco-cement [13, 14].
1.2 Influence of Selected Mineral Additives on Concrete
Properties
The use of mineral additives in concretes has a beneficial effect not only on reduction
of CO 2 emission to air by substitution of the Portland cement clinker with industry
by-products [12]. Another advantages of their use is higher durability of the concrete
made, it’s denser structure or better resistance to corrosion [12, 15, 16].
A. Kaleta-Jurowska et al.
often the waste materials are used as mineral additives to the cement (fly ash, silica
fume, ground-granulated blast-furnace slag) [3].
New solutions are still being searched for aiming at utilization of various types of
waste. The waste material of a great significance for the environment is tire rubber. As
data presented in [4] show the approximate weight of scrap-tires generated annually
only in the USA is estimated at 3.6 million tons. Tests showed that concretes with tire
rubber addition had much lower density, better ductility, better resistance to impacts
and better sound-proof properties. However, in case of concretes made of normal
cements, a drastic reduction of the compressive strength is observed [5].
A natural substitute of aggregate, which allows to get light concrete, are coconut
shells. There are also research studies conducted to replace sand and a part of cement
with calcareous tuffs. Results of research often demonstrate a beneficial impact of
individual waste materials on selected properties of the concrete made with their
application, however, the environment-friendly aspect of waste materials utilization
is emphasized [6].
To put it simply, production of the Portland cement includes the following phases:
grinding of raw materials, their firing in temp. 1500 °C and then grinding of clinker
with gypsum. It is estimated that energy needed to produce one ton of the cement is
about 4000 MJ. As most of mineral additives requires grinding only, their use saves
a lot of energy [7].
Production of Portland cement is one of the most important factors in CO 2 worldwide emission strategy [8]. Statistic data show that in 2017 China had the largest
production of the cement equal to 2.38 Bnt. The next places are taken by India
(423 Mt/yr), and then the USA (120.5 Mt/year) [9]. A high CO 2 emission is caused
by the fact, that the Portland cement clinker production requires combustion of solid
fuels (for calcination of limestone in high temperatures) [2]. Production of the clinker
also requires transport of raw materials and electricity supply to the cement plant.
Therefore it is estimated that the cement industry in total accounts for 8% of the
global emission of carbon dioxide [10, 11]. Reduction of these values is possible
due to utilization of mineral additives as substitutes for the clinker [12] or through
application of waste materials such as phosphogypsum and waste limestone sludge,
waste stone sludge, iron oxide sludge, and spent catalyst as raw materials in the
production of the so-called eco-cement [13, 14].
1.2 Influence of Selected Mineral Additives on Concrete
Properties
The use of mineral additives in concretes has a beneficial effect not only on reduction
of CO 2 emission to air by substitution of the Portland cement clinker with industry
by-products [12]. Another advantages of their use is higher durability of the concrete
made, it’s denser structure or better resistance to corrosion [12, 15, 16].