GB/T 20491-2017 English PDF (GBT20491-2017)

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GB/T 20491-2017: Steel slag powder used for cement and concrete
GB/T 20491-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.99
H 54
Replacing GB/T 20491-2006
Steel slag powder used for cement and concrete
ISSUED ON. SEPTEMBER 7, 2017
IMPLEMENTED ON. JUNE 1, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of the PRC;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 6 
2 Normative references ... 6 
3 Terms and definitions ... 7 
4 Technical requirements ... 7 
5 Test methods ... 7 
6 Inspection rules ... 8 
7 Packing, marking, transport, and storage ... 11 
Foreword
This Standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This Standard replaces GB/T 20491-2006 “Steel slag powder used for cement
and concrete”. As compared with GB/T 20491-2006, in addition to editorial
modifications, the main technical changes are as follows.
- DELETE “products of steel slag powder combined with ground granulated
blast furnace slag powder and fly ash” in the “Scope”;
- DELETE the definitions of “comparison sample, test sample, comparison
mortar, test mortar, activity index, fluidity ratio” in the “Terms and definitions”;
- In the definition of steel slag powder, CHANGE “When grinding, it is allowed
to add appropriate amount of gypsum in accordance with GB/T 5483 and
cement grinding process admixture conforming to JC/T 667” to “When
grinding, it is allowed to add cement grinding aid in accordance with GB/T
26748”;
- For the specific surface of steel slag powder, “The primary and secondary
specific surfaces are not less than 400 m2/kg” is changed to “The primary
and secondary specific surfaces shall ≥350 m2/kg” (SEE Table 1);
- The density of steel slag powder is changed from “not less than 2.8 g/cm3”
to “≥3.2 g/cm3”;
- The free calcium oxide content of steel slag powder is changed from “not
more than 3.0%” to “≤4.0%”;
- DELETE the definition and index of the basicity factor of steel slag powder;
- ADD chloride ion content index of steel slag powder. The value is ≤0.06%;
- The fluidity ratio is changed from “not less than 90” to “≥95”;
- In the soundness of steel slag powder, autoclave method is changed from
“When the content of MgO in steel slag is more than 13%, it shall be
qualified” to “6 h autoclave expansion rate ≤0.50% (If the content of MgO
in steel slag powder is not more than 5%, autoclave soundness may not be
inspected)”;
- The reference method for the determination of free calcium oxide content
is changed from “YB/T 140 ‘Methods of chemical analysis of steel slag’” to
“YB/T 4328 ‘Determination Method for Free Calcium Oxide Content in Steel
Slag’”;
Steel slag powder used for cement and concrete
1 Scope
This Standard specifies the terms and definitions, technical requirements, test
methods, inspection rules, packing, marking, transport, and storage of steel
slag powder used for cement and concrete.
This Standard is applicable to steel slag powder used for cement and concrete.
2 Normative references
The following documents are indispensable for the application of this document.
For the dated references, only the versions with the dates indicated are
applicable to this document. For the undated references, the latest version
(including all the amendments) are applicable to this document.
GB/T 176 Methods for chemical analysis of cement
GB/T 208 Test method for determining cement density
GB/T 750 Autoclave method for soundness of Portland cement
GB/T 1346 Test methods for water requirement of normal consistency,
setting time and soundness of the Portland cement
GB/T 2419 Test method for fluidity of cement mortar
GB/T 8074 Testing method for specific surface of cement - Blaine method
GB 8076 Concrete admixtures
GB/T 9774 Sacks for packing cement
GB/T 12573 Sampling method for cement
GB/T 17671 Method of testing cements - Determination of strength
GB/T 51003-2014 Technical code for application of mineral admixture
YB/T 022 Steel slag used for cement
YB/T 804 Terminology for iron and steel slag and treatment and utilization
It shall be carried out according to GB/T 8074.
5.2 Density
It shall be carried out according to GB/T 208.
5.3 Water content
It shall be carried out according to Appendix C of GB/T 51003-2014.
5.4 Free calcium oxide
It shall be carried out according to YB/T 4328.
5.5 Sulfur trioxide
It shall be carried out according to GB/T 176.
5.6 Chloride ion
It shall be carried out according to GB/T 176.
5.7 Activity index and fluidity ratio
It shall be carried out according to Appendix B of GB/T 51003-2014. Cement
for inspection shall use reference cement for performance test of concrete
admixture conforming to GB 8076. The test sample is prepared by mixing steel
slag powder and reference cement at a mass ratio of 3.7.
5.8 Determination of soundness
The autoclave method inspection is carried out in accordance with GB/T 750.
Autoclave time is 6 h.
The boiling method inspection is carried out in accordance with the provisions
of pat test in GB/T 1346.
Cement for inspection shall use reference cement for performance test of
concrete admixture conforming to GB 8076. The test sample is prepared by
mixing steel slag powder and reference cement at a mass ratio of 3.7.
6 Inspection rules
6.1 Numbering and sampling
6.1.1 Numbering
- When the exit-factory inspection result is significantly different from the last
type inspection.
6.4 Judgement rules
6.4.1 The products of which the inspection results meet the technical
requirements of Table 1 are qualified.
6.4.2 The products of which the inspection results do not meet the technical
requirements of Table 1 are unqualified. Except for the soundness index, if any
of the items does not meet the requirements, double samples shall be re-taken,
for reinspection of the non-conforming items. The result of the reinspection shall
prevail in the assessment. The activity index, after reinspection, can be
degraded to use. If the soundness is unqualified, it cannot be re-inspected and
shall be as a non-conforming product.
6.4.3 If the type inspection result meets all the requirements of Table 1, the type
inspection shall be judged as qualified. If the type inspection result does not
meet any of the requirements in Table 1, the type inspection shall be judged as
unqualified.
6.4.4 The contents of the inspection report shall include exit-factory inspection
items and other technical requirements stipulated in the contract. When the
user needs, the manufacturer shall, within 11 d from the date of delivery of steel
slag powder, send the test results except the 28 d activity index. The 28 d
activity index shall be supplementally reported within 32 d from the date of
delivery of steel slag powder.
6.5 Delivery and acceptance
6.5.1 At the time of delivery, the quality acceptance of steel slag powder can be
based on the inspection results of the physical samples taken; or be based on
the inspection report of steel slag powder of the same number of the
manufacturer. The method for acceptance shall be agreed upon by the supplier
and the buyer and be stated in the contract or agreement. The supplier has the
responsibility to inform the buyer of the method for acceptance. When there is
no written contract or agreement, or the acceptance method is not specified in
the contract or agreement, the supplier shall indicat...