GB 200-1989 Medium heat Portland cement Low heat slag Portland cement

GB 200-1989 Medium-heat Portland cement Low-heat slag Portland cement GB200-1989 Standard download and decompression password: www.bzxz.net

National Standard of the People's Republic of China
Medium heat Portland cement
Low heat slag Portland cement
Moderate heat portland cementLow heat portland slag cement1Theme content and scope of application
GB200-89
replaces GB200-80
This standard specifies the definition and technology of medium-heat Portland cement (referred to as medium-heat cement) and low-heat slag Portland cement (referred to as low-heat slag cement) requirements, test methods and inspection rules, etc. This standard applies to cement used in dams and mass concrete projects that require low hydration heat. 2 Reference standards
Cement chemical analysis method
Cement mortar strength test method||tt ||Granulated blast furnace slag used in cement
Cement stability test method (pressure steaming method) GB1345
Cement fineness test method (sieve analysis method)
Cement standard consistency Test methods for water consumption, setting time and stability GB1346
GB1596
Fly ash used in cement and concrete
GB2022
GB2419
GB5483
GB6645
Test method for heat of hydration of cement (direct method) Determination method of fluidity of cement mortar
Gypsum and anhydrite in cement
Used in cement Granulated electric furnace phosphorus slag in www.bzxz.net
GB9774
Cement packaging bags
3 Definitions
3.1 Medium heat Portland cement: Portland cement with appropriate composition Clinker is added with an appropriate amount of gypsum and ground into a hydraulic cementitious material with medium heat of hydration, which is called medium heat Portland cement. 3.2 Low-heat slag Portland cement: A hydraulic cementitious material with low heat of hydration made by grinding Portland cement clinker with appropriate components, adding slag and an appropriate amount of gypsum, and grinding it into pieces. It is called low-heat slag Portland cement. . The amount of slag added to cement is 20% to 60% by weight, and it is allowed to replace part of the slag with phosphorus slag or fly ash not exceeding 50% of the total amount of mixed materials. Note: ① Slag, phosphorus slag and gypsum must comply with the regulations of GB203, GB6645 and GB5483 respectively. Fly ash should comply with the regulations of GB1596. When the user requests low alkali, the alkali content shall be expressed as Na20 (Na20 + 0.658K20) equivalent. greater than 2.0%. When using industrial by-product azurite, it must be tested and submitted to the provincial, municipal, and autonomous region building materials industry authorities for approval. ② When grinding cement, it is allowed to add grinding aids that do not damage the performance of the cement, and the amount added does not exceed 1% of the weight of the cement. The National Building Materials Industry Bureau approved the implementation on 1989-12-01 on March 16, 1989 | Cement is divided into two grades: 325 and 425. 5 Technical requirements
5.1 Tricalcium aluminate and tricalcium silicate
The content of tricalcium aluminate in the clinker shall not exceed 6% for medium-heat cement and 8% for low-heat slag cement; The tricalcium silicate content in the clinker shall not exceed 55% for medium heat cement. 5.2 Magnesium oxide
The magnesium oxide content in clinker shall not exceed 5%. If the cement passes the autoclave stability test, it is allowed to be relaxed to 6%. 5.3 Free calcium oxide
When producing medium-heat cement, the free calcium oxide content in the clinker shall not exceed 1.0%. When producing low-heat slag cement, the free calcium oxide content in the clinker shall not exceed 1.2%.
5.4 Alkali
The alkali content shall be agreed upon by both supply and demand parties. When cement may react harmfully with aggregates in concrete and the user requests low alkali, the alkali content in medium-heat cement clinker shall not exceed 0.6% in terms of Na20 (Na20+0.658K20) equivalent, and the alkali content in low-heat slag cement clinker shall not exceed 0.6%. The alkali content in it shall not exceed 1.0%.
5.5 Sulfur trioxide
The sulfur trioxide content in cement shall not exceed 3.5%. 5.6 Fineness
0.080mm square hole screen residue shall not exceed 12%. 5.7 Setting time
The initial setting shall not be earlier than 60min, and the final setting shall not be later than 12h. 5.8 Stability
The stability of cement must be qualified.
5.9 Strength
The strength value at each age shall not be lower than the value in Table 1. Table 1
Compressive Strength
Product
Medium Heat Cement
Low Heat Slag Cement
5.10 Heat of Hydration||tt ||Mark
3 days
20.6||tt| |The heat of hydration at each age should not exceed the values ??in Table 2. 7 days
28 days
3 days
Flexural strength
7 days
4.5||tt ||5.3
28 days
5.4||tt| |6.3
Cement grade
6 test methods
GB200—89
Table 2
Hot Cement
Medium
3 days
7 days
low heat slag cement
3 days
7 days
230| |tt||230
6.1 Calcium oxide (CaO), silicon dioxide (SiO2), aluminum oxide (Al2O), iron oxide (Fe2Os), magnesium oxide (MgO), sulfur trioxide (SO;), The determination of free calcium oxide and alkali content shall be carried out in accordance with the provisions of GB176. 6.2 The tricalcium aluminate content X (%) and tricalcium silicate content X2 (%) in the clinker are calculated according to the following formula: 6.72Al,O—1.43Fe2O—2.85SO:6.3 The fineness is measured according to GB1345.
6.4 The determination of setting time and stability shall be carried out according to GB1346. 6.5 The determination of pressure steam stability shall be carried out in accordance with GB750. 6.6 The strength is measured according to GB177.
6.7 The measurement of heat of hydration shall be carried out in accordance with GB2022. 7 Inspection Rules
7.1 Numbering and Sampling
Sampling of cement of the same variety and label before leaving the factory. No more than 400t is a number. Each number is a sampling unit. Sampling should be representative and can be taken continuously, or equal amounts of samples can be taken from more than 20 different parts, with a total of at least 14kg. 7.2 Test and retained samples
The cement samples obtained for each number should be thoroughly mixed. Divide it into two equal parts, one part shall be tested by the cement factory according to the method specified in Chapter 6 of this standard; the other part shall be sealed and kept for three months in case of doubt, and submitted to the nationally designated inspection agency for re-inspection or arbitration. 7.3 Judgment rules
7.3.1 If any of the magnesium oxide, sulfur trioxide, stability, initial setting time, and heat of hydration does not meet the requirements of Chapter 5 of this standard, and the strength is lower than the minimum label index, it shall be for scrap.
7.3.2 If any of the fineness, final setting time, mixing amount, tricalcium silicate, tricalcium aluminate, free calcium oxide and alkali content does not comply with Chapter 5 of this standard If the specification or intensity is lower than the index specified in the product label, it is a non-conforming product. 7.4 Test report
The cement factory shall send the cement quality test report within 11 days from the date of cement issuance. The test report includes the test results in Chapter 5 of this standard except for the 28-day strength. The 28-day strength value shall be reported within 32 days from the date of cement dispatch. The test report should also fill in the name and mixing amount of the mixed materials, and should be accompanied by the technical requirements of the cement. 7.5 Arbitration
Within three months after the cement leaves the factory, if the purchasing unit raises questions about the quality of the cement or problems related to the quality of the cement arise during the construction process and require arbitration by the cement quality supervision and inspection agency, the cement factory shall Sealing samples of cement with the same number were carried out. If the user has questions about the cement stability and initial setting time and requires on-site sampling for arbitration, the manufacturer shall work with the user on-site to take samples within 7 days after receiving the user's request and send them to the cement quality supervision and inspection agency for inspection. If the manufacturer does not go to the site within the specified time, the user can take samples and submit them for inspection separately, and the results will be equally valid.
8 Packaging, marking, transportation and storage
8.1 Packaging and marking
GB200-89
Cement can be packed in bags or in bulk. The net weight of each bag is 50±1kg. The packaging bag must be clearly marked with: factory name, cement type (abbreviation), label, packaging year, month, day and serial number, and the name of the grinding aid. The cement name and number should also be printed on both sides of the packaging bag. Packaging bags should comply with the regulations of GB9774. When packing in bulk, a card with the same content as the bag mark must be submitted. 8.2 Transportation and Storage
Cement must not be affected by moisture or mixed with debris during transportation and storage. Cement of different varieties and labels should be stored separately and must not be mixed. Additional notes:
This standard is under the jurisdiction of the China Academy of Building Materials. The main drafters of this standard are Zhen Xiangxian and Huang Chunjiang. This standard is interpreted by the Cement Institute of the China Academy of Building Materials. This standard was first published in 1963.
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