Concrete is a structural material that is extensively used globally. Generally, plain concrete by itself lacks the ability to carry the load in tension or withstand the impact of heavy loads, once the cracks in it begin to develop in its cement matrix. To offset this problem, two materials, Steel and Concrete, must combine together to provide strength and reinforce concrete. A good bond between steel deformed reinforcing bar and concrete in concrete structures is vital for structural and serviceability performance; a good bond mechanism allows the forces to be transferred between the concrete and steel. If this bond is inadequate, then the concrete structure’s behavioral and failure characteristics will be altered.
Generally, in concrete construction, many kinds of contaminants are present on the site like form oil for coating the forms and bond-breaker in tilt-up construction. As a result, the reinforcement can get contaminated during construction, if adequate care is not taken. In case, the structure gets contaminated, then there will be considerable issues with the bond strength and specifications.
To avoid issues as these, it’s important to get the two materials – Steel and Concrete, bond well to provide strength to reinforced concrete. That is possible only with TMT bars, not ordinary bars; TMT bars since their evolution have proven to be a viable solution for reinforcing concrete structures. Combined together, they withstand induced forces in a way wherein the TMT bars resist tensile and shear forces whilst the concrete resist the compressive forces. That is how the concrete structure began to be callused as Reinforced Cement Concrete (RCC).
Since its evolution, RCC has dramatically altered the face of construction industry by becoming the most effective construction material. With its high compressive strength compared to other building materials, and its ability to undertake any shape, it has become the most preferred construction material.
WHY REINFORCEMENT IS NEEDED IN CONCRETE?
As the compressive strength of concrete is very high, tremendous force is required to crush concrete. But concrete has a relatively weak tensile strength which means less force is required to crack concrete by twisting or bending it than is required to crush concrete.
Since the tensile strength of the concrete is weak, steel reinforcement bar (TMT bar) is required to improve the tensile strength of the concrete. Furthermore, TMT bars are needed for their superior elongation which takes care of the stresses and strengthens the concrete to withstand all kinds of loads.
Concrete reinforcements should be free from loose rust, oil paints, mud, etc, and be in a position to cut, bent, and fixed properly. TMT bar meets all of these criteria requirements and functions as a strong steel reinforcement as bars of circular cross-section in concrete structure, like a skeleton in human body.
The reinforcement is placed and maintained in position, providing proper cover blocks, spacers, supporting bars, laps, etc and also placed and tied in a way that makes concrete placement possible without segregation and compaction possible by an immersion vibrator.
HOW TMT BARS REINFORCES CONCRETE?
As reinforcement, TMT bars makes concrete several times more resistant to failure. A combination of the following factors helps TMT reinforce concrete structures.
- TMT process equips the TMT bar with superior strength and anti-corrosive properties. Controlled water-cooling prevents the formation of coarse carbides, which is the main cause for the corrosive nature of the common bar.
- Soft ferrite-pearlite core enables TMT bars to bear dynamic and seismic loading. Add to this, the bars high ductility quality offers high fatigue resistance to dynamic/seismic loads.
- Tough surface offers high-yield strength and a soft core providing excellent ductility.
- Strength properties that comes from quenching and tempering (no mechanical treatment is involved).
- Carbon content in TMT bars is restricted to 0.2% which helps them to attain weldability while at the same time; no strength is lost on this account. Joints can be welded by ordinary electrodes and no extra precautions are required.
- Combination of high elongation values and consistent properties throughout the length of the bar, equips it with excellent workability and bend-ability.
HOW TMT BARS WORK EFFECTIVELY AS REINFORCEMENT?
- Properties of thermal expansion for both TMT bars and concrete are approximately the same. This combines with TMT bars excellent bendability to effectively reinforce concrete structures.
- TMT bars bonds well with concrete. As passive reinforcement, TMT bar is strong in tension and at the same time, ductile enough to be shaped or bent; this put together helps the concrete structure to stay strong.
REINFORCEMENT TESTS
The following tests are performed to identify the proposed strength of the reinforced bar.
- Tensile Test is the most common test performance. Under this test, the TMT bar is strained by the tensile force and elongated generally to the point of failure. This is to determine its tensile strength.
- Yield-Stress Test subjects the TMT bar to deform plastically (cannot be reshaped to the original).
- Percentage Elongation Test subjects the TMT bar to varied levels of elongation ranges. This will test its ability to deform prior to breaking. Each grade TMT bar has its own purpose and is specifically designed for that purpose.
- Bend and re-bend tests evaluates the ductility of the TMT bar. Under these tests, the TMT Bar is bent by bending it at the midpoint resulting in bending without fracture. Likewise, the re-bend test involves measurement of the effect of strain ageing on the TMT bar.
TMT bars as a tensioning device reinforces concrete to help hold the concrete in a compressed state. It compensates for concrete’s lack of strength in tension and slab’s behavior, by carrying the tensile loads. To firm up the concrete structure better, the TMT bars can be patterned to form a better bond with the concrete.
VINAYAK STEEL TMT BARS – MOST VIABLE CHOICE
India is witnessing rapid growth in infrastructure construction development. TMT steel bars have become an important essential for these construction activities thus fuelling demand for them across construction sites in the country.
With growing demand for quality TMT steel bars, finding the appropriate TMT bars for construction needs will become more paramount. Currently, there are various grades of TMT bars available in the marketplace. Each of the grades represents the strength and rigidity of the TMT bar, specifically the yield-strength of reinforcements. When zeroing in on the right TMT bars, factoring in the strength of TMT bars based on their grades, is important.
The higher the grade, the better the TMT bars are. It is here that Fe 500D Grade TMT Bars provides the ideal confluence of strength & flexibility in line with IS Standards. Further, their extreme flexibility in line with the same norms makes them ideal for all types of construction purposes.
Leading TMT steel bars manufacturer, VINAYAK STEEL INDUSTRIES offers the finest of genuine strongest and long-life TMT steel bar Fe-550, that conform to IS: 1786:2008 BIS standards (a standard equivalent to a number of international standards like ASTM A615 Grade 60 of the USA; BS 444 Grade 460 of Britain; BST 500 of DIN 488 of Germany).
VINAYAK STEEL’s LIMITED high-grade Fe-550 TMT Bar has proven time and again its extreme robustness and strength. Add to this, it also guarantees top-notch equilibrium, safety and stability to a concrete structure; and great resistance on dynamic loading with varied yield and tensile strength.
Manufactured with the latest technology, every Fe-550 TMT Bar undergoes robust quality-check process including extreme anti-corrosion testing methodology, in intense rusting conditions. The high calibre of their quality can be estimated from the fact that every VINAYAK’s Fe-550 TMT Bar, carries a BIS Certification confirming adherence to IS 1786:2008 (Contains the Standard Mark, Cast / Lot number, Grade, Size, & Corresponding test results).
An ideal construction material for all kinds of construction structures from coastal, to marine or underground, VINAYAK STEEL’s LIMITED Fe-550 TMT Bars are best selected in accordance with the design requirement of a construction structure.
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