Model of Power Earthquake Resistant Steel Bars G 72
The advance manufacturing process of Thermo Mechanical Treatment (TMT) makes it surpass the minimum limit of strength and ductility speci¬fied in the standards. The yield strength also far exceeds the standard norms and specifications.
The UTS/YS ratio and percentage elongation that determine the seismic property of a rebar is also very high in Thermo Model Treatment signi¬ficantly enhance its ability to handle the pressure of earthquakes.
The Thermo Mechanical Treatment (TMT) steel bars are manufactured after the incoming scraps are analyzed for chemical composition and are segregated for unwanted material like cast iron, non-ferrous etc. the billets are tested to maintain the certifi¬ed composition of carbon, Sulfur & phosphorus much lower than the speciation. This results in more longevity, excellent ductility, higher bend ability, better corrosion resistance and superior weld ability and enhances its intrinsic quality to withstand load under adverse conditions. Bars are manufactured from superior quality billets, in adherence with the international quality standards and norms to ensure quality consistency.
Since 1969, grand 50 years of pride and customer satisfaction, customer loyalty & trust is an enviable accomplishment by Model Steel Group of Companies. Model steel believes in creating and promoting the customer satisfaction in simplifying order, after sales service, production testing prompt delivering and use of best raw material. By this method the unnecessary Steps, Misunderstanding and dispute are well addressed right on spot and immediately, which reduce the cost of construction.
What is Earthquake?
Earthquake is a release of energy at the focus or hypocenter (epicenter on earth's surface) of earth quake by breaking of the rocks. This energy in the form of waves of vibration travels to the buildings. Same earthquake on Richter scale have larger effect s on areas near the epicenter and minor effects on areas away from the earthquake. Similarly, shallow depth earthquakes usually cause more damage than deep earthquakes. This energy enters the buildings through their foundations and they start vibrating.
The frequency of the vibration continuously and very significantly changes. The mass of the building tries to resist this vibration due to its inertial property due to which lateral earthquake forces are produced within the structure and are called "earthquake forces". The greater is the mass of the building, the more earthquake forces it will generate for the same earthquake. The natural time period of the building is also an important factor that determines the magnitude of the earthquake forces.
Steel Bars and its use in Earthquake zones:
1. ZONE 0,1 and 2A
All type s of steels, including TOR steel, manufactured according to standards and under strict quality control may be used for Zones 0, 1 and 2A.
Twisted BSS 4441 & Deformed ASTM A615 - G40, G60, ASTM A706 G-60 and Cold Twisted Bar.
2. ZONES 2B, 3 and 4
Satisfying the requirements of ASTM or BS must be used in zones 2B, 3 and 4. However, TMT steel of prescribed quality may also be used in these areas. ASTM A615- G 40, G 60, ASTM A706 G-60. BS 4449:2005 G-500 (G72), ASTM A615 G-75.
In Zones 2B, 3 and 4, the steel used must have ultimate strength higher than 1.25 times the yield strength and the percentage elongation must be greater than the ASTM or BS requirements.
Pakistan Earthquake Zone Map
Greater Bond Strength Due to The State of Art Vertical & fish Ribs Technology:
Model Steel bars are rib-patterned enabling better strength between the bars and the adjacent concrete. It enhances the strength of the structure thus giving it better and longer lives attach with better ribs. The strength of a construction depends on the quality of Model Steel bars used in it and most importantly the ribs on these bars. Model Steel bars bear very prominent ribs that give them improved adhesiveness, and provide the construction with higher strength and a longer life.
Cost Saving Model of Power Earthquake Resistant Steel Bars
According to ACI (American Concrete Institution) code the consumption of steel bars kg per square foot G500 (G-72) is 30% less as compare to grade 40 & 20 % less as compare to grade 60.
Cost Saving in Construction
There is the growing interest within the reinforced concrete industry in using higher strength reinforcing steel for certain applications. This interest is driven primarily by relief of congestion; particularly in buildings assigned a high seismic design category. There are also other areas where high strength concrete –allow reinforced concrete to be used in more demanding applications. Today, the vast majority of concrete design and construction uses Grade 60 steel, with occasional but increasing use of Grade 500.
Actually, higher grades are often used to permit smaller concrete members, relating to the space problems for placement of the reinforcement.
It has been found that Grade 500 steel is allowed as reinforcing bar in all international building codes and standards. From a design standpoint, all the current codes limit the allowable design strength of reinforcement to 80 ksi (550 MPa). Using Grade 500steel instead of commonly available Grade 415 bars in the market, economy can also be achieved.
Main advantage of using Grade 500 steel is to remove the steel congestion at beam column joint and in the foundation mat. However, development length for Grade 500 steel is higher than development length for Grade 415 steel. To get maximum benefi¬ts for Grade 500 steel, higher strength concrete and good engineering judgments are required.
Always use building materials as per/ recommended Civil Engineer / Designer.
Advantages of Model of Power Earthquake Resistant Steel Bar
Cost of Contruction Comparision:
Determination of Concrete and Steel Volume for Flat plate slab (Using ACI Code)
For estimation purpose of total steel, Negative reinforcements at column strips are provided up to 0.3L from column supports and 25% of total negative steel are assumed continuous for seismic resistance.
Negative reinforcements at middle strips are provided up to 0.22L from column supports.
Earthquake Resistant Construction:
- A proper design on earthquake resistant reinforcement using ground solidifi¬cation for underground structure.
- Proper load sharing through columns & beams (height, width).
- Fatigue Calculation.
- Supersonic sounds create huge amount of vibrations in the building, calculations & precaution needed.
- Vibration created by Htv, Ltv underground & overhead trains systems. Proper building design needed.
- Earthquake Forces diffusion design needed.
- Water oods or humid environment needs special building design.