Brief Information on Rebars
BENEFITS OF USE OF HIGH (YIELD) STRENGTH DEFORMED BARS IN R.C.C. STRUCTURES
1. Following materials are used in the R.C.C. structures:-
(1) Cement (2) Steel (3) Sand (4) Aggregates (5) Water
2. Different types of steel bars used in R.C.C. works are mentioned below: 1) Mild Steel plain bars (Generally M.S. round bars are used) 2) Medium Tensile Steel bars 3) High yield strength deformed bars (H.Y.S.D. bars) 1. Mild Steel Bars (M.S. Bars) In past, mild steel was available in two different categories. 1. M.S. Plain Bars:-
M.S. plain bars of round section confirm to I S 432 – Part – I, 1982 (Grade-I) and (Grade-II) is most commonly used and easily available in the market. It’s diameter denoted by Ø. The permissible tensile strength of the mild steel confirm to grade-I of I S 432 – Part-I, 1982 is a) 140 N/mm² for bars up to and including 20 mm Ø b) 130 N/mm² for bars over 20 mm Ø The permissible tensile strength for mild steel confirming to grade-II of I S 432 – Part-I, 1982 is @ 90 % of grade-I bars. Hence if the design details have already been worked out on the basis of Mild Steel confirming to grade-I of I S 432 – Part-I, 1982 and it happens to use grade-II of Mild Steel than the area of reinforcement shall be increased by 10 % of the required for grade-I steel. More over I S 432 – Part-I, 1982 does not recommend the grade-II M.S. bars for use in structures located in earthquake zone subjected to severely damage and structures subjected to dynamic loading (other than wind loading)
2. M.S. Deformed Bar (or Deformed Mild Steel Bars):- In past deformed M.S. bars were also available in the market confirm to I S 1139 – 1966. Deformed bars are furnished with lugs, ribs or other surface deformation. The technical specification of such deformed bars are
1. Following materials are used in the R.C.C. structures:-
(1) Cement (2) Steel (3) Sand (4) Aggregates (5) Water
2. Different types of steel bars used in R.C.C. works are mentioned below: 1) Mild Steel plain bars (Generally M.S. round bars are used) 2) Medium Tensile Steel bars 3) High yield strength deformed bars (H.Y.S.D. bars) 1. Mild Steel Bars (M.S. Bars) In past, mild steel was available in two different categories. 1. M.S. Plain Bars:-
M.S. plain bars of round section confirm to I S 432 – Part – I, 1982 (Grade-I) and (Grade-II) is most commonly used and easily available in the market. It’s diameter denoted by Ø. The permissible tensile strength of the mild steel confirm to grade-I of I S 432 – Part-I, 1982 is a) 140 N/mm² for bars up to and including 20 mm Ø b) 130 N/mm² for bars over 20 mm Ø The permissible tensile strength for mild steel confirming to grade-II of I S 432 – Part-I, 1982 is @ 90 % of grade-I bars. Hence if the design details have already been worked out on the basis of Mild Steel confirming to grade-I of I S 432 – Part-I, 1982 and it happens to use grade-II of Mild Steel than the area of reinforcement shall be increased by 10 % of the required for grade-I steel. More over I S 432 – Part-I, 1982 does not recommend the grade-II M.S. bars for use in structures located in earthquake zone subjected to severely damage and structures subjected to dynamic loading (other than wind loading)
2. M.S. Deformed Bar (or Deformed Mild Steel Bars):- In past deformed M.S. bars were also available in the market confirm to I S 1139 – 1966. Deformed bars are furnished with lugs, ribs or other surface deformation. The technical specification of such deformed bars are