The material of the rebar is steel. A steel section that is responsible for a large part of the task of bearing and transmitting pressure. Different types of rebar are produced and used in the industry. They are also produced with different standards in different countries. In general, rebars are produced in grades A1-A2-A3 and A4. The diameter of the rebars is 6, 8, 10, 12, 14, 16, 18, 20, 22, 25, 28, 32, 36, 40 and 50 mm.
The rebar that has treads or ridges on its surface is called ribbed rebar, which are widely used in construction. Another type of rebars are simple rebars that do not have treads. Each of the rebars has different uses and features. Another type of rebar has high flexibility and has a smooth and polished surface, which is called coil or wire rod.
Ribbed rebars are usually used in construction and simple rebars are used in various industries.  Normally, rebars are used from the lowest point of the building in the foundation to the highest point of the building to shape the building.

From the time of construction of shelters and houses in the heart of the mountains by human beings to the present time and the use of decorative stones and facades in magnificent buildings and towers, stone has been used as one of the important building materials. In addition to construction, another use of stone is in construction and sidewalk projects. Over the years with the advancement of technology, equipment and machinery related to this huge industry; Consumption of various stones has also been increasing.
Granite, travertine, marble, marble, etc. are the most important building stones. These stones without deformation and with deformation in different parts of the building such as foundations, floors, walls, facades, etc., as well as for civil works such as paving roads and sidewalks, walls of dams and bridges, etc. Are used. Building stones are divided into the following two general categories:
1- Foundation stones on which not much work is done. These stones are used in the form of carcasses, shards, etc., following buildings, walls and arches of buildings, paving yards and streets, bridge walls, etc.
2- Decorative stones and facades that after cutting in different sizes, they are polished and in the appearance of the building such as exterior and interior walls, building floor, stairs, tunnel walls, especially subway tunnels, etc., case Are used.
This trading group has provided all kinds of building and construction stones such as marble, granite, travertine, etc. in the form of blocks , slabs and tiles from the best mines in the country for international marketing and export. 

• Marble
Marble is one of the dense limestones that in addition to beauty and variety of colors, has high strength and resistance. This type of rock is obtained from the density of calcium deposits and has low porosity, fine or medium granulation with sugar texture. There is a lot of color variety due to the presence of materials such as mica, serpentine, silica, etc. in marble. This type of stone is available in creamy, light yellow, brown, black, etc.
The most important provinces of Iran that have marble mines are Azerbaijan, Lorestan, Kermanshah, Khorasan and Isfahan.

• Marble (Onyx)
Onyx is one of the metamorphic limestones that is used as one of the precious stones in the interior of the building due to its ability to pass light and its dazzling radiance. It can be said that marble is the same as metamorphic travertine. This type of stone has a high resistance to cold and heat and in addition to being uniform, has a high ability to sand and polish. Due to these outstanding features, it has long been one of the most important stones in the art of sculpture.
Among the most important constituents of marble are calcite and aragonite. This type of stone due to having aluminum, magnesium and iron has various colors such as green, white, lemon, pink, turquoise blue, etc. The most important provinces of Iran that have marble mines are Azerbaijan, Kurdistan, Kerman and Khorasan.

• Travertine
Travertine is one of the limestones that has been formed from the deposition of calcium carbonate related to the fourth geological period (quartz period) and over many years. This type of stone, in addition to beautiful appearance, wide color spectrum, polishability, etc., also has high resistance. Travertine stones are available in two forms, wavy and undulating, which are more resistant to undulating types.
Due to the relatively suitable weight (about 2500 kg per cubic meter) and also good adhesion due to the pores on the stone surface, this type of stone is easily used in the exterior of the building.
This type of stone is available due to the elements of iron oxide, silica, manganese in lemon, brown, red, silver, etc. colors. The most important provinces of Iran that have travertine mines are Azerbaijan, Yazd, Isfahan and Markazi.

• Granite
Granite is one of the outer igneous rocks that is the result of cooling of volcanic molten material. The texture of this type of stone is small and medium, which gives it a dazzling beauty. This type of stone is used in interior paving of stairs, stairs, cabinet plates, sculpture, etc. due to its strength, durability, hardness and very high polishing properties. In addition to these applications, granite is also used in the production of kitchen sinks due to its hygienic nature.
This type of stone due to having elements of mica, feldspar, quartz, …exists and is produced in colors like gray, white, golden yellow, turquoise, green, etc. The most important provinces of Iran that have granite mines are Azerbaijan, Zanjan, Khorasan, Hamedan, Yazd and Sistan and Baluchestan.

Cement
Cement is a powder that is produced from limestone and clay. Its mixture with other materials such as sand, gravel and stone is used to make all kinds of mortar and concrete. Cement is used in concrete, and its function is only to stick the grains together, and it does not have an effect on strength and load.
Cements have limestone roots. In other words, the main material of cement and cement ingredients is lime (calcium oxide). Cement is a combination of calcium oxide (lime) with other oxides such as aluminum oxide, silicon oxide, iron oxide, magnesium oxide and alkaline oxides that have the tendency to combine cement with water and become hard and resistant in the vicinity of air and under water. 
Cement, as one of the constituents of concrete, plays an important role in creating various features and characteristics for it. Today, different types of cement are produced and marketed in bulk or 50 kg bags, each of which is specific to one or more purposes. The types of cement are:



• Fast hardening cement
• Expansive cement
• Hydrographic cement
• Pozzolanic cement
• Colored cement
• Aerated cement
•  White cement
• Fastening cement
• Cement with high alumina
• Cement with low heat generation
• Cement with high sulfate resistance
• Cement made from furnace slag


In general, construction cements are divided into two types: Portland and non-Portland.
The types of Portland cement are divided into five types based on the iranian standard- which is based on the ASTM standard- which are:
Type 1 - Ordinary Portland cement
Type 2 - Modified Portland cement
Type 3 - quick-hardening Portland cement
Type 4 - Portland cement with low heat
Type 5 - anti-sulfate portland cement


Clinker

Clinker or furnace slag are gray and dark colored grains that are observed in the diameter of 3 to 21 mm. Cement is a powder material and is used in construction, but clinker is used in cement production. Clinker is obtained during the cement production process inside the furnace.
When the raw materials (clay and limestone) are placed inside the furnace under intense heat up to 1500 degrees Celsius, at the highest temperature, clinker is obtained with a sudden decrease in temperature.
The produced clinker can be kept in a dry place for a long time, so that its properties do not change. from clinker in cement factories in areas where raw materials for cement are scarce and simply not available; is used Based on this and in order to produce different types of cement, 5 types of clinker are produced based on ASTM standards.

Cement production from clinker is done in two ways, wet and dry. In wet cement production, clinker is mixed in water and then ground, but in dry cement production, clinker and other raw materials are combined and ground dry.