Bulk density of rubble - what does this characteristic mean?
Rubble of the smallest fraction is used for landscape design, the device of garden paths, decorative finishes and so on. Crushed stone of the largest fraction, which is a fragment of rocks, is used as a rubble material. The most popular middle fraction is used to create reinforced concrete products, concrete mixtures, foundations, as well as for the construction of roads, bridges, railways and other.
Bulk density of rubble is one more quantity that must be taken into account when working with this material: stripping or laying, calculation of the concrete composition. This ratio of the volume occupied by rubble to its total mass. In other words, this is the density of the rubble in the unconsolidated state.
Special vessels of a certain shape, up to 50 liters, are used for measurements. This value should be calculated as follows: the mass of the empty vessel is subtracted from the mass of the vessel filled with gravel, the resulting number is divided by the volume of the empty vessel. In this way, the bulk density of any loose building material is calculated.
Scattering of crushed stone: the essence of the process
The construction of the crushed stone foundation for the roadway is made in the construction of roads, bridges, runways. The base of crushed stone must have high strength and density, because the roadway will be subjected to high loads. To make the base as dense as possible, the technological process of the dissection is applied.
Scuffing of rubble is a process of laying a crushed stone base with the use of grains of different fractions. As a matter of fact, this filling of emptiness between grains of a coarse fraction by grains of a fine-grained rubble that gives to the basis the maximum durability. In accordance with the technology of roadway construction, the installation of crushed stone must be carried out in several stages.
First laying of grains of a larger fraction, 50-70 mm, more rarely 80-120 mm. After that, it must be sealed using special road rollers. Further, rasklinkovka material of the fine fraction and seal the roller. Then the next rasklinkovka with the addition of crushed rock of even finer fraction, after each - compaction of rubble roller.
Depending on the requirements for the roadway, up to three raskltsovok can be produced. To reduce friction between crushed grains, they must be watered. The technological process of dissection can be used not only in the construction of roads, but also in the manufacture of reinforced concrete products and structures.
Coefficient of compaction of rubble - why should you know this parameter?
Compacting of soil with rubble is used mainly in the construction of buildings. Such a technological process is carried out to avoid subsidence of the underlying layers, otherwise, with improper compaction, the crushed stone and compacted soil will shrink with time, which will lead to the formation of voids between the layer and the floor plate, whereupon the floors will be covered with cracks.
The ramming of rubble is an indispensable condition for the creation of a strong and quality foundation for the construction of roads or buildings. For ramming, you can use a roller, vibratory plate or manual ram( for small volumes).
To check the quality of the seal, a special device is used, which determines the degree of ramming by the dynamic sounding method: after several impacts on the surface of its disk, it calculates the shrinkage of the crushed stone. If, according to the instrument, the degree of shrinkage is normal, then it is possible to continue the expansion and consolidation of the following layers of crushed stone.