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BUREAU OF INDIAN STANDARDS (Eastern Region Office, Kolkata)
DRAFT PRODUCT CERTIFICATION MANUAL FOR COMMENTS Our Ref: DDGE/22/IS 6006 Dated: 20 Feb 2014 Sub: Draft manual for IS 6006 This has reference to CMD circular CMD:1/31 dated:11 Nov 2013 on the above subject. In this connection, please find enclosed the draft product certification manuals as per details below: UNCOATED STRESS RELIEVED STRAND FOR PRESTRESSED CONCRETE Kindly examine the draft product certification manual and forward your comments on the draft to ERO at email@example.com , in the format given below:
Sl no Clause no/page no Comment
Last date for comments: 05 March 2014. (Product Certification Officer) ERO
Revision Number 00
UNCOATED STRESS RELIEVED STRAND FOR PRESTRESSED CONCRETE
AS PER IS 6006:1983 (Incorporating Amendment No. 4)
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9, BAHADUR SHAH ZAFAR MARG,
NEW DELHI 110002
Sl No Page No Amendment no. Amendment dt Remarks / Reasons for amendment
This standard was first published by Bureau of Indian Standards in 1970 to cover the requirements of strands used in prestressed concrete work. The standard was revised in 1983. During revision, significant modifications incorporated relating to physical requirements of nominal mass of strand and proof load and the sample size for tensile test. Further, SI units have been adopted in the revision and references to related Indian Standards appearing in the standard have been updated. In the formulation of this standard, due weight age has been given to international co-ordination among the standards and practices prevailing in different countries in addition to relating it to the practices in the field in this country.
This Manual for Uncoated Stress Relieved Strand for Prestressed Concrete provides general guidelines for various aspect related to certification of the above product. This document is intended for internal use by BIS officers only.
TABLE OF CONTENTS
Section No Title Pages ------ Amendment Sheet 01 ------ Foreword 02 ------ Table of Contents 03
1 Product Description 1.1 Product Description 04
1.2 Latest Indian Standard Number with Product Title and Number of Amendments 04 1.3 List of referred Indian Standards for raw materials / components and test methods 04 1.4 Check-list for submission of an application for grant of licence 05-06
2 Raw Materials / Components 2.1 List of important Raw Materials 07
3 Manufacturing Process and In-process Quality Controls 3.1 Description of Manufacturing Process(es) 08
3.2 Infrastructure for production 08 4 Certification Criteria
4.1 Identification of Critical Requirements of the Indian Standard 09 4.2 Scheme of Testing and Inspection 10-14 4.3 Marking Fee Rates 15 4.4 Grouping Guidelines, if any 15 4.5 Guidelines for writing Scope of Licence 15 4.6 Guidelines for Inclusion of new Varieties 15 4.7 Sample size, including guidelines for drawal of separate samples when samples are
required to be sent to different labs for testing 15
4.8 Manner of Sealing of Sample(s) 15 4.9 Whether remnants of sample(s) are returnable / non-returnable, to be scrapped / used,
to be deshaped before disposal In case of safety items), any other precaution required for dealing with remnants
4.10 Procedure to be followed for destroying / deshaping / recycling the product that does not meet the quality parameters during regular production
5 Inspection and Testing 5.1 Packing Material requirement (for Packing / Dispatch of Samples) 15
5.2 List of Test Equipment / Facilities with requirement and frequency of Calibration 15 5.3 Status of Test Facilities in BIS Labs and OSLs with Testing Charges, and
approximate time required for testing by BIS labs / OSLs 15-17
5.4 Whether GOL will be based on Factory testing basis or Independent testing basis or Mixed (factory testing basis plus independent testing of some raw materials)
5.5 Tests to be carried out in the Factory in case of Applicant / Verification Samples / Surveillance / Market Samples / Raw Material Samples to be got tested, if any
Section I: Product Description
1.1 Description of Product(s)
Two Wire Strand - The nominal diameter, the nominal crosssectional area and the nominal mass per unit length of the strand shall be as given in Table 1. The two wire strand shall be designated by the number of element wires ( plies) and the diameter of the element wire making the strand, for example, 2-ply 2 mm strand will mean a strand consisting of t\VO element wires of diameter 2 0 mrn each.
Two wire strand
Three Wire Strand - The nominal diameter, the nominal crosssectional area and the nominal mass per unit length of the strand shall be as given in Table 1. The three wire strand shall be designated by the number of element wires ( plies ) and the diameter of the element wire making the strand, for example, 3-ply 3 mm strand will mean a strand consisting of three element wires of diameter 3.0 mm each.
Three wire strand
Seven wire strand - The nominal diameter, nominal cross sectional area and nominal mass per unit length of the strand shall be as given in Table 2. The nominal diameter of strand shall be measured across the crown of the wires. The seven wire strand shall be designated by the approximate overall diameter of the strand and number of element wires ( plies) making the strand, for example, 6.3 mm 7-ply strand will mean a strand of approximate diameter 6.3 mm and made out of seven ( six outer and one central) wires.
Seven wire strand Class 1and Class 2
The tolerance on the nominal diameter of the element wire in case of two wire and three wire strands and the tolerance on the nominal diameter of the strand in case of seven wire strand shall be as given in "Tables 1 and 2 respectively. 1.2 Latest Indian Standard Number with Product Title and Number of Amendments
IS 6006:1983, No. of Amendments 4. 1.3 List of referred Indian Standards for raw materials / components and test methods
IS No. Title IS 228 relevant parts Method for chemical analysis of steel IS 1608/ISO 6892 Metallic Materials - Tensile Testing at Ambient Temperature IS 1387 General requirements for The supply of metallurgical materials
1.4 Check-list for submission of an application for grant of licence
Section II: Raw Materials / Components
2.1 List of important Raw Materials / components, including those which are required to conform to the relevant Indian Standards
Wire The base metal shall be carbon steel of such quality that when drawn to suitable round wire sizes and fabricated into proper strand sizes and properly stress relieved after stranding, shall have the properties and characteristics as prescribed in this specification. The element wire to be used for strand shall be cold-drawn from plain carbon steel and shall contain not more than 0.050 percent of sulphur and not more than 0050 percent of phosphorus, when tested in accordance with relevant parts of IS : 228.
Section III: Manufacturing Process and In-process Quality Controls
3.1 Description of Manufacturing Process(es)
The wire used in the manufacture of the strand shall be well and cleanly drawn to the specified dimensions and shall be sound and free from splits, surface flaws, piping, and any other defects likely to impair its use in the manufacture of the strand and the performance of the strand -in prestressed concrete.
Strand The seven wire strand shall have a centre wire at least 1.5 percent greater in diameter than the surrounding wires enclosed tightly by six helically placed outer wires with a uniform length of lay of at least 12 times but not more than 16 times of the nominal diameter of the strand. The length of lay for the two and three wire strands shall be uniform throughout and shall be 24 to 36 times the diameter of element wire. The wires in the strand shall be so formed that they shall not unravel when the strand is cut and they shall not fly out of position when the strand is cut without seizing.
Joint-There shall be no strand joints or strand splices in any length of the completed strand unless specifically permitted by the purchaser. During process of manufacture of individual wires for stranding, welding is permitted only prior to or at the size of the last heat treatment ( patenting ). During fabrication of the 7 wire strand, butt-welded joints maybe made in the individual wires, provided there is not more than one such joint in any 45 m section of the completed strand.
Note - When specifically ordered as weldless grade, a product free of welds shall be supplied. When this grade is specified, no welds or joints are permitted except as detailed in 3.3.2 of the specification.
Stress Relieving or Strand - After stranding, all strands shall be subjected to a stress-relieving. Stress relieving shall be carried out as a continuous process on a length of strand by uncoiling and running through any suitable form of heating to produce the prescribed mechanical properties. Temper colours, which may result front the stress-relieving operation, shall be considered normal for the finished appearance of the strand. After stress relieving, the strand shall be reformed into coils or wound on to reels, havin