Similar to a skeleton which gives proper appearance to our body, steel gives the required structure to the building. It is hence necessary to assess the quality of steel to ensure a strong and structured home.
As you know, steel is used in combination with concrete for construction of slabs, footings, lintels, and stairs. High strength in compression is brought with concrete. However, to provide high tensile strength for reinforcements, steel is used along with concrete. Read through to know about quality features of steel.
Types and grades of steel
General construction purposes use two types of steel including the mild and deformed steel bars. The mild steel bars which are used in reinforced cement concrete works are plain in surface and round in cross-section. Whereas the deformed ones have ribs or deformations on their surface. Sometimes, certain cracks may be formed in the reinforced cement concrete around mild steel bars. This is because the bars stretch and reduce the bond with concrete. The projected deformations of the deformed bars avoid this problem and improve the bond with concrete.
More commonly, steel bars of grades Fe 415 and Fe 500 are used for construction purposes. The number of the grade indicates the yield stress. Fe 415 graded steel is being used mostly nowadays among the two. The steel bars are available in different ranges of diameter from 6mm to 50mm. However, those having diameter from 6mm to 20mm are used for home constructions.
Checking the quality of steel on site
The quality of steel used for reinforcement works is determined by its tensile strength, yield strength, weight and elongation. In addition, the chemical composition like the Carbon, Sulphur, Manganese, and Phosphorous content affects the quality. Various laboratory tests are conducted to check the quality of steel before supplying. However, it is difficult to know all these things for a common man. Therefore, ask your builder to ensure that they are tested before being purchased from the supplier. The good quality steel bars should be sound and free from surface flaws and cracks. They should not have rough, jagged and imperfect edges.
A simple test called bend test conducted on site can assess the quality of steel. When you bend the steel rod to make an angle of 90 to 135 degrees and then bend it back straight, there should be no cracks on it. If the original shape is retained once it is straightened, you can assure that it is of best quality.
Things to consider while purchasing steel
Do not forget to check the following things when purchasing steel bars
- Ensure the presence of the BIS certification mark.
- Get the details of the quality of steel.
- Purchase from the reputed manufacturers. Also, check for the trademark on every bar.
- Ensure that same sized rods are given without any errors.
Remember that a proper storage of steel bars on site is necessary. They must be kept under shade in dry conditions to prevent rusting. Ensure that they are not exposed outside for more than one month. Wash them with cement slurry if they are exposed so. Clean the re-bars that are already rested before usage.
It is on your part to assure that the best quality steel rods are used for grills, windows, reinforcement work and others. Remember, any deviations in the specifications of the steel may weaken the structure of your building.