Cold rolled ribbed steel bars
1 Scope
This standard specifies the terms and definitions, classification, designation, dimension, appearance, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and certification of cold-rolled ribbed steel bars.
This standard is applicable to cold-rolled ribbed steel bars used for prestressed concrete and ordinary reinforced concrete, it is also applicable to the cold-rolled ribbed steel bars used for manufacturing welded mesh (hereafter referred to as simply steel bars).
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) is applicable to this document.
GB/T 2101 General requirement of acceptance packaging, marking and certification for section steel
GB/T 2103 General requirements for checking, packing, marking and certification of steel wire
GB/T 17505 Steel and steel products - General technical delivery requirements
GB/T 21839 Test methods of steel for prestressing concrete
GB/T 28899 Wire rods for cold rolled ribbed steel bars
GB/T 28900 Test methods of steel for reinforcement of concrete
YB/T 081 Rule for rounding off of numberical values and judgement of testing values for technical standards of metallurgy
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
cold rolled ribbed steel bars
steel bars with ribs evenly distributed along the length on the surface of hot-rolled wire rods after cold rolling
3.2
nominal diameter
nominal diameter of plain round bar equivalent to cross sectional area
3.3
specific projected rib area
ratio of the product of the projected area of the rib on a plane vertical to axial line of steel bar to the nominal perimeter and the spacing between ribs
3.4
rib spacing
chord length of the discontinuity of the ribs on the circumferential surface of the bar projected perpendicular to the axis of the bar
4 Classification, designation
4.1 Classification and symbols
Cold-rolled ribbed steel bars are classified into two categories by ductility:
Cold-rolled ribbed bars CRB
High elongation cold-rolled ribbed bars
CRB + tensile strength characteristic value + H
C, R, B, H are the first letter of the four English words Cold rolled, Ribbed, Bar and High elongation.
4.2 Designation
Steel bars have 6 designations, i.e. CRB550, CRB650, CRB800, CRB600H, CRB680H and CRB800H. CRB550 and CRB600H are for ordinary reinforced concrete, CRB650, CRB800 and CRB800H are for prestressed concrete, CRB680H can be used for either ordinary reinforced concrete or prestressed concrete.
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Classification, designation
5 Dimension, appearance, weight and allowance deviation
6 Technical requirements
7 Test method
8 Inspection rules
Cold rolled ribbed steel bars
1 Scope
This standard specifies the terms and definitions, classification, designation, dimension, appearance, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and certification of cold-rolled ribbed steel bars.
This standard is applicable to cold-rolled ribbed steel bars used for prestressed concrete and ordinary reinforced concrete, it is also applicable to the cold-rolled ribbed steel bars used for manufacturing welded mesh (hereafter referred to as simply steel bars).
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) is applicable to this document.
GB/T 2101 General requirement of acceptance packaging, marking and certification for section steel
GB/T 2103 General requirements for checking, packing, marking and certification of steel wire
GB/T 17505 Steel and steel products - General technical delivery requirements
GB/T 21839 Test methods of steel for prestressing concrete
GB/T 28899 Wire rods for cold rolled ribbed steel bars
GB/T 28900 Test methods of steel for reinforcement of concrete
YB/T 081 Rule for rounding off of numberical values and judgement of testing values for technical standards of metallurgy
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
cold rolled ribbed steel bars
steel bars with ribs evenly distributed along the length on the surface of hot-rolled wire rods after cold rolling
3.2
nominal diameter
nominal diameter of plain round bar equivalent to cross sectional area
3.3
specific projected rib area
ratio of the product of the projected area of the rib on a plane vertical to axial line of steel bar to the nominal perimeter and the spacing between ribs
3.4
rib spacing
chord length of the discontinuity of the ribs on the circumferential surface of the bar projected perpendicular to the axis of the bar
4 Classification, designation
4.1 Classification and symbols
Cold-rolled ribbed steel bars are classified into two categories by ductility:
Cold-rolled ribbed bars CRB
High elongation cold-rolled ribbed bars
CRB + tensile strength characteristic value + H
C, R, B, H are the first letter of the four English words Cold rolled, Ribbed, Bar and High elongation.
4.2 Designation
Steel bars have 6 designations, i.e. CRB550, CRB650, CRB800, CRB600H, CRB680H and CRB800H. CRB550 and CRB600H are for ordinary reinforced concrete, CRB650, CRB800 and CRB800H are for prestressed concrete, CRB680H can be used for either ordinary reinforced concrete or prestressed concrete.
Contents of GB/T 13788-2017
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Classification, designation
5 Dimension, appearance, weight and allowance deviation
6 Technical requirements
7 Test method
8 Inspection rules
