Properties of deposit and type of construction stone

Before designing the mine, all issues in the field   ofmineralogy and mineralogy should be carefully studied, first, information such as deposit shape, type of mineral, chemical composition, storage amount, tailings thickness, place of use and like other deposits.    In addition,  in the case of the deposit of construction stones, the properties andproperties such as bending resistance, abrasion, khbandan, heat, cold, water absorption, stone state in terms of softness and hardness in cutting, year and tickling, color of stone and its changes in the deposit, stability or color fluctuation of the stone under the influence of  Atmospheric factors, seams and crevices system, lag, special gravity, thermal properties, ease or difficulty in  the themeofleakage and … The     study of the contract (Nabiyan et al., 1991).

 Different stones that are chosen as building stones, in general, should have a minimum in terms of some characteristics, these minimums may be for a variety of granite, sandstone, limestone, etc. In addition, the utto be determined in terms of the location of stone consumption (according to the climate of the region, architectural style and its installation location) in terms of size and other characteristics and standards.

The stone extracted from the mountain must have special specifications to be used.  More importantly, the desired characteristics of stone are:

1. Lack of effects on the phenomenon of alteration

 The inner igneous rocks are most prepared for alteration, during the alteration process, minerals such as alkane feldspars, plagioclases and feldsparoids, p-roxons and olivine, which are the main minerals of the rocks’ mattress.  These are, if the conditions of alteration such as water with appropriate pH, soluble salts, heat, etc. Provide, easily transform and become secondary minerals, during which the texture of the stones is weakened and disintegrated and the properties of the building stones are lost.  If even the degree of alteration is small, the building stone will not be suitable.

If the stones are sensitive to alteration, be sure to make a thin cross section of several samples before any action, check the alteration function under the microscope by   the lithographer or perform X-ray analysis.   They investigated the presence   or absence of alteration-induced minerals.

2. Lack of complicationsofnetology

The presence of   drains and gaps in the text of the stone, whether in relatively large drains or small drains, reduces the resistance of the stone and overshadows its ability to extract and process in the stone factory from the first stage when the stones are peaked under the apparatus.  The process to the last stage, which is beveling and drying (especially in the calibration and substrate stages that are of particular importance to igneous rocks), is likely to disintegrate in many cases these drains and especially in the rocks.  Limestone is filled with pads of dozens of secondary and the stone has the necessary resistance, most of these drains, which appear as veins, have a different color to the text of the stone.

 If the drainage system is such that these drains have many distances than each other, so that the boulders can be extracted from it, the extraction conditions are more suitable. In other words, the 10-ale construction stone mine is a mineral that can be extracted along the seam system and the gaps in the working chest, large blocks and can be extracted so that the surfaces of the extracted rock fragments are the surfaces of the natural seams.  The drains cause problems in the extraction method by cutting wire crushes.  It is possible that the existence of the oppression of the drainage in the mine, according to the expert’s diagnosis, also negates the use of cutting.

3. Not having schistocytes and labands

A stone with a sheet structure or schistosity usually has the lowest resistance in parallel with the surface of the turquoy.  Stones with schistocites (such as L’s, etc.) are not suitable for the construction of coupe extraction workshops for stone façade because of the impossibility of working on them and the laxity   of   all thin stone units. Becentimeters, used to make malone.  The proper lily for the preparation of the cup should be such that it can be extracted along the compartment with the appropriate sizes, in cases where the thickness of the layers is the size of one of the sizes of the coupe so that the surface of the band is in a way that the surface of the bandis the same.  One of the surfaces of the coupe is the ideal situation provided.

4- Having the ability to cut, sub and polish

One of the main characteristics of building stones is their ticklishness, this factor is undoubtedly a very important parameter in determining the popularity, price and amount of stone sales, an experienced person   can only comment on the degree and quality of the stone by observing the stone. Slow. The stones, which are pitted due to tectonic stresses, tissue disharmony or weathering effects, have little ability to polish and certainly have little market and therefore will not have a high price by conducting a few experimental experiments on the sample coupe   of the ability to cut, sub and polish the stone.  Dodd.

The higher the specific gravity of   the stones, the more polishability it will be, usually the stones with a specific weight of less than 1500 kg/cm m3 are polished and the stones with a specific weight of more than 2400 kg/cm3 have very good polishability and are not.   The specially weighted stones between the two have a polished web.

5. Having acceptable difficulty

The hardness of   the building stones varies greatly so that the range of hardness changes of these stones varies from very low hardness (soap stone) to more hardness than steel (granite), the hardness in the finished price of the stone and also for use in a particular place that requires a lot of pressure and abrasion tolerance.

  The hardness    of the stones, especially the stones used in the floors and stairs, should be enough, too, the conditions of cutting and polishing the stone, and the cost of preparing the stone, therefore, the hardness should be at an acceptable level because of their high hardness, expensive; But these    stones are more expensive because of their beauty and good resistance, making ordinary stones like travertine because of the low hardness, much cheaper.  Theserock species are in good resistance.

6- Having attractiveness in terms of beauty of colors and colors

The importance of color in stones is not covered by anyone, even some architects prefer the color of the stone and its effect on the building or the interior of the building over any other quality in the stone.    Stones may have a different appearance in different polished sections, in cutting copes should be selected the most beautiful section, the desired stone has a uniform and bright color and its color changes against sunlight and ambient weather.  However, the beauty and attractiveness of the color depends on the market and the taste of the customer, so that sometimes and in certain places, the market of different stones has different elasticity, but due to the diversityof human demand, the desired color may be and the pattern used in the stone may vary.

The  importance and role  of the stone color is clear, so that perhaps the most effective factor in choosing the stone is from the architects’ point of view, of course, the style and shape of the building, the taste of the buyers is effective in preferring the color to another color,  but  due to the change in people’s tastes, which in the years not too far was more used than the stone façade with bright white, bone or cream color;  But now most of the fashion or taste  is  towards the use of  green, black or red green, or red, of course,  in a city with high pollution rates like Tehran, perhaps  in the form of  a wiser use of the field of color.  Be. Or, for example, both white travertine and walnut and red types of this stone have a forming method and even the white sample in some cases is more resistant to the color type, butthe color type has a price several times the white type.

7. Lack of clay layers inside the stone

Some rocks are apparently resistant and strong, but due to the full distance   of grains from clay, their resistance in the vicinity to water is the lowest amount, clay compounds are more susceptible to weathering than other minerals, so their existence in building stones is undesirable, so the existence of la la. Clay’s hey inside the stone should be examined.

 Marni limestones, which have a small percentage of clay, are    simply cut and polished, less resistance to pure limestone and soon to be worn out.   In most cases, they are not suitable for use in stairs, corridor floors, and cedars. In general, the presence of more than 3% of clay materials in limestone used as building stones is not permitted by performing the mineralological decomposition of the rocks by X-ray method to simply find out the clay percentage in them (Nabiyan et al., 1991).

8- Low porosity and water absorption coefficient

 One of the most important parameters that must be taken into consideration by the buyer and the consumer is the amount of porosity in the façade stones, which is one of the main factors in breaking and separating the stone from the surface of the building.  Water between the stone and the wall or the floor, and due to the cold below zero degrees, initially creates minor seams and gaps and eventually breaks and separates one or more plaques from the surface of the building, causing our bodies to become and cause problems to find plaques with the same design and color and replace the new stone.

9- Having good friction, compressive and tensile strength

Depending on the location of the stone consumption, the stone must have the necessary frictional, compressive and tensile strength. For most construction work, compressive strength of 400 kg/cm2 is enough.

10- Having good durability

  In spite of the beliefs of many people who consider the stone to be the destruction of the   immaterious B, the building stones are composed of minerals and materials that are under certain conditions to be attacked and changed under certain conditions.   Building stones should be    considered against factors such as weathering, fire, heat and cold, and the weathering agent should   be divided into two chemical and physical components, such as the effect of factors such as   deoxycarbon, DXYD.  Sulfur and oxygen and physical factors such as freezing water, melting ice and the effect of sunlight and heat that constantly affect the stone can be very influential, so in choosing the right stone, weather conditions should be considered so that, for example, in areas with high rainfall and carbonic gas, the use of rocks should be considered.   Calcareous and especially travertine is not suitable.

Carbonaterocks are prone to chemical weathering in acidic climates, for example stone sculptures dating from 1170 onwards and located in the Industrial Region of The Reine-Ruhr, Germany, have been undergoing a rapid collapse since the early 19th century, and their clarity has declined.    The grains and their cement (64%) are calcite, and their weathering includes a combination of chemical weathering of calcite by attacking rock cement and physical weathering through the growth of salt   minerals in pore spaces, speeding up a polluted atmosphere of both types of weathering.

11. Ease of Extraction

The ease of extraction is more important in judging the stone to choose it as a construction stone, the situation of the mine should be such that large and flawless pieces of stones can be extracted.

  In terms of extractive stones, the10alter blocks of stone are blocks with a topographic slope of less than 30 degrees, and the possibility of constructing a way to reach their upper points is simply as well as close to urban facilities and main communication routes.

12. Sufficient storage

One of the desirable characteristicsof the stone is that for at least one period of economic exploitation, sufficient reserve can be extracted.

13. Other Factors

Considering   the location of the stone installation in the building and the climatic environment where they are used, andthe desired jags of the stone may change, for example, a stone that is good in color, tickling and uniformity of the grains, but has little frictional resistance, can.  In the façade and walls, it will be used as a desirable stone, but it will be undesirable on the floor, or a stone that has all the characteristics of a good stone, but its resistance to squabbling is low, for cold areas, for use in the outer parts of the building undesirable, but for use in non-populated areas.   In areas where there is a lot of rainfall and carbonated gas in the space, the use of limestone, especially travertine, is not reasonable for the exterior of the buildings.