News

Jun 23, 2023

Purpose of Markings on Reinforced Steel Used in Construction

In the wake of several buildings collapsing across the country, techniques are

In the wake of several buildings collapsing across the country, techniques are incorporated to ensure the strength, integrity and quality of reinforced concrete structures.

Markings on rebars - steel reinforcement bars - are crucial in enhancing adherence to industry standards. They enable engineers and contractors to identify and interpret crucial details regarding the steel accurately.

By facilitating effective communication and verification, these markings ensure that the right rebars are used in the appropriate places, contributing to the overall strength, durability, and safety of the concrete structures.

Kenyans.co.ke looks at the purpose of the four markings on the reinforced steel and their role in contributing to the safety and longevity of various infrastructure projects.

The first mark identifies the manufacturer of the reinforcement bar. This is either an alphabet or a symbol predesignated by the manufacturer.

For instance, the letter H is used by sellers to denote Grade 500 steel which is considered a high-strength, low-alloy steel and falls within international standards.

The second marking means the bar size, where the designation number correlates with the weight per foot of a square bar.

For instance, bar sizes 3 to 9 correlate with a square bar less than one inch in diameter. However, from designation number 9, it has the same weight per foot as a one-inch square bar and above.

The third character refers to the type of steel. It is depicted by four different types of steel represented by four different characters:

S stands for billet steel, I stands for rail steel, A represents axial steel, and W stands for low alloy steel.

The fourth mark shows the steel grade of the particular bar. To put it into perspective, the steel grade highlights the tensile strength of the bar per square. The grade can also be pinpointed by the number of lines running for at least five spaces.

The government has been cracking down on buildings that contravened the standards set for construction materials.

Kenya Bureau of Standards (KEBS) Managing Director Bernard Njiraini recently disclosed that some of the affected materials were structural steel, cement, and roofing tiles.

"We have an elaborate way of protecting consumers against any manufacturing who will be attempting to reduce the quality of materials they are manufacturing," Njiriani emphasised on April 2, 2023.