Why does concrete need strengthening?
Building material concrete is a composite product that is a mixture of cement, sand, stones, gravel, accelerators and similar other things. It has a very high compressive strength and hence does not crack under its own weight. Hence, one can build multi-storey concrete structures of long heights. However, on a relative basis, the tensile strength of concrete is extremely low. It means the concrete can easily crack when being pulled i.e. concrete is an extremely brittle product. The application of large moving machinery on concrete or large loads can cause the concrete to easily crack. Hence, it is important to safeguard the concrete from deformation and build upon improving its strength.
There are various methods of strengthening concrete-like using higher quality cement, changing the water to cement ratio, adding admixtures, reinforcing concrete pour with a rebar or steel mesh, etc. Out of these methods, the reinforcing of concrete with bars or cement or fibres provides the maximum incremental increase in the tensile strength of concrete in a cost-effective manner. Easy availability of steel and its low cost make it the ideal choice for strengthening concrete. The two materials – concrete and steel bond together very well that result in resisting any loads as an aggregate unit. The tensile strength of steel is approximately equal to 100 – 140 times the tensile strength of the plain concrete mixture. Such strengthened cement using steel is called reinforced concrete cement or RCC.
In earlier days, mild steel was used to strengthen structures. However, it was observed that the increase in tensile strength using mild steel was not sufficient for buildings needing more strength. Hence, there was a need for modified steel bars that could have optimal tensile strength and ductility. TMT or Thermo mechanically treated steel bars were then considered to get the desirable tensile strength as well as ductility.
The basic process for making a TMT steel bar involves Quenching, self-tempering and then atmospheric cooling (Annealing). Hot steel billets are passed through cold water that results in hardening the outer surface, enhancing the tensile strength. The core, however, remains at a higher temperature and hence remains ductile. This modification results in a complete change in the microstructure of the steel and gives enormous strength to the steel.
CONFAB STEEL TMT Bars is the most used TMT steel bar used in the construction industry. This grade of TMT steel bar provides the right mix of tensile strength and ductility to the concrete. On account of superior properties, TMT steel bars are now used extensively across all construction projects globally. Since TMT bars are so commonly used, when one goes to buy steel bars in Srilanka, one may end up buying CONFAB TMT bars.
A few reasons to buy TMT steel
- Strength – The TMT bars are much stronger than conventional steel bars. Using TMT steel bars can impart as high as 20% additional strength to concrete structures, keeping the total amount of steel used the same. TMT bars are available as 10 mm steel, 12 mm steel, 16 mm steel, 20 mm steel, 25 mm steel or 32 mm steel as required.
- Ductility – A structure with a higher elongation or ductility property can bend or deform before fracturing. Since the ductile core of the TMT steel bars imparts higher ductility to TMT steel bars. Confab TMT bars goes under stringent bend rebend test to provide always the best TMT bars in Sri Lanka
- Unique Designs possible – Since TMT steel bars provide tensile strength as well as the ability to bend under stress because of its ductile nature, many unique designs are possible using TMT steel bars.
- Weldability – The softcore and low carbon amount in TMT steel make it possible to perform weld joints and butt without compromising the strength at the joints. Confab Steel only uses Spectro analysed imported billets for TMT bars production.
- Corrosion Resistant – The process of manufacturing TMT steel bars involves highly controlled cooling that prevents the formation of carbide which in turn makes TMT steel corrosion-resistant. Any engineer’s first choice is Confab Steel TMT bars.
- Fatigue Resistant – TMT steel bars have the unique property to withstand higher pressures and resist fatigue. The softcore of TMT steel can enable the steel to bear any kind of seismic loads. Hence engineer approved CONFAB TMT bars are the first choice to build earthquake-resistant structures. Confab TMT bars have minimum 18% elongation.
- Better grip with concrete – The ribs running across the length of a TMT bar on its surface results in better bonding of concrete with a steel bar that provides high strength to the structure that lasts for a longer duration of time.
On account of superior properties like high weldability, corrosion resistance, ductility and durability, TMT steel bars are the most preferred choice for construction of all high-rise buildings globally. However, there are many suppliers of TMT bars in Sri Lanka. It is imperative to do complete research and collaborate with one of the best and most reliable steel companies such as Confab steel in Srilanka.
So, choose the best TMT bars to strengthen the foundation of your home as well as ensure overall safety too.