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Building Materials

August 12, 2017 18:08

Secondary gravel and others of his species in modern construction

rubble Properties

most important characteristic of this material is considered flakiness - a parameter that determines the degree of rubble plane, because it can be prickly grains and platelet-shaped.And the higher the flakiness, the better the material.

That is, the flatter the shape of the stone has, the better, as it provides a dense ramming.What can be said in the presence of angular shapes that lead to the formation of voids, and therefore need to spend on the binder mixture filling them.

Depending on the content of the material grains and prickly plate shape are the following groups: normal, improved and cubiform rubble .The first may contain from 15 to 50% of the grains, the second - from 10 to 15% and the third - 10%.Consequently, the most cubiform rubble quality and reduce consumption of mixtures of binders up to 30%, it still increases the strength and durability of asphalt concrete structures.

flakiness addition, one can distinguish such a property as radioactivity, it is I and class II.

first class - the presence of radionuclides of about 370 Bq / kg, the second - 740 Bq / kg.Class I is used for various construction jobs, and to create suitable roads class II.In addition, there are also two indicators, which pay attention when buying - it frost resistance and durability .They are indicated by the letters F and M. The higher the score, the greater the resistance is crushed stone to frost or strength.

Species rubble

Depending on the material and method of processing the following types of crushed stone: granite, gravel, slag, limestone, secondary.There are still some types, but we will describe below.To begin with let's deal with the main types.

  • Gravel ( or river gravel ), which is produced in two ways.First - by crushing and screening stone cliffs.The second - a typical charge is rounded sea or river pebbles.By the way, Washed gravel also applies to this type.He has one advantage over granite rubble - a low radioactive background.But it is inferior in strength.Apply for concrete work, laying the foundation, the construction of roads.
  • Granite rubble prepared from granite rock (solid rock).In fact, this magma, which froze at great depths.It is used as an additive in a variety of construction work, as well as for decorative finishes.According to its characteristics this kind of material has the best performance in strength and flakiness.
  • limestone or dolomite , it is derived from sedimentary rock by chopping it.Consisting mostly of calcium carbonate.It is used in reinforced concrete construction and establishment of roads.
  • secondary or blast rubble made from construction debris (ie remnants of brick, concrete, asphalt).In many respects (frost resistance and strength) of the material is inferior to the granite rubble.But with all this, it can also be successfully used for the improvement of roads, for soil stabilization, to add to the concrete, etc.
  • slag gravel form of the crushed steel slags.its cost is much lower, but lower strength characteristics.Because this material is often used to strengthen the foundations, building structures and asphalt roads.Come in different sizes and fractions.For example, the most popular private gravel, having a size of 40 mm.

few words about the other types of rubble

Apart from common species there are also some other types.For example, porous gravel (or expanded clay).It is made from clay with additives and then sintering.We call this method "wet".The technology is quite complex and time-consuming.But there is another way, "dry".

However, it is used instead of clay solids, that do not require any training and immediately fired.This may be perlite or any shales low in carbon components (less than 0.2%).Use porous rubble for more concrete, which are further used for heat insulation.