History of limestone crushed stone
Limestone was formed in sea basins from the remains of mollusks and crustaceans shells, animal skeletons and chemical sediments. It resulted from the impact of groundwater on organic residues. This is evidence of the millennial life of the planet.
Popular monuments of architecture - the Egyptian pyramids and the Great Wall of China are composed of limestone. Crushed limestone, whose technical characteristics were known even in the distant past, served as the basis for the construction of Moscow. It is because of its color that the capital is called white stone.
Properties and characteristics of rubble
Dolomite crushed stone is resistant to temperature changes and has high impact resistance, it is harmless and environmentally friendly. It has a small water absorption and water saturation, high frost resistance. A small amount of impurities can give it a reddish, white, yellow or brown color.
Compared to granite, it has less radiation activity and a greater binding property, its products are of excellent quality. Its bulk strength coefficient is much lower than that of granite, which means that the consumption of such rubble is less. Its cost is much lower than that of other species. A disadvantage is only one - a relatively low strength.
Also important is the quality of flakiness or the degree of flatness( from the word "bream" or "flat as bream").The lower this index, the more compact is the ramming.
The best crushed stone is cube-shaped, its flakiness index is about 10%, in this mixture there are almost no voids. When using cube-shaped rubble, the consumption of the binder solution is the least. Used such rubble as a facing stone, for the construction of roads with a small transport load, in the production of lime, Portland cement, soda, mineral fertilizers, calcium carbide, to strengthen glass, in the manufacture of reinforced concrete and in printing.
Fractional variety of crushed stone
Dolomite crushed stone is produced in 3 fractions( grain size in mm):
- 5-20;
- 20-40;
- 40-70.
Limestone crushed stone 5-20 more often than others serves as a filler in the production of concretes. Small reinforced concrete structures are also often made from this very shallow fraction. From it roads are constructed with little bandwidth. Sometimes used for facing buildings. It is this fraction that is used as a raw material in lime production.
Rubble, limestone for which is crushed to the fraction of 20-40, is in demand more than others. The foundation of it is perfect. The paths and areas covered by this faction retain their attractive appearance for a very long time. The production of medium reinforced concrete construction and the construction of roads is the main purpose of this fraction. They are also lined with buildings and used in the production of lime.
Crushed stone 40-70 is rarely used alone. It is made from a ballast layer or gravel cushions for roads, railway embankments and tramways, and massive reinforced concrete structures are manufactured. Facing buildings with this faction is rare, only in very large projects. For the production of lime, this fraction has to be further crushed.
Calcareous crushed stone 20-40 - an indispensable bulk material in construction. It is an excellent bonding material and filler. Strength and frost resistance ensure good stability of roads and buildings to the whims of our climate, which in winter is completely ruthless.