1、MIL-G-20098C 31 January 1969 SUPERSEDING See Section 6 MILITARY SPECIFICATION GYSUM, CALCINED This specification is mandatory for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 hemihydrate). 1.2 Classification. as specif ied : This specification covers calcined gypsum
2、 (calcium sulfate The calcined gypsum shall be of the following types, . Type I - Fast setting Type II - Slow setting 2. APPLICABLE DOCUMENTS 2.1 for bids or request for proposal, form a part of this specification to the extent specified herein. The following documents of the issue in.effect on date
3、 of invitation SPECIFICATIONS FEDERAL RR-S-366 - Sieves, Standard for Testing Purposes UU-S-48 - Sack, Shipping, Paper PPP-C-96 - Cans, Metal, 28 Gauge and Lighter STANDARDS MILITARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes MIL-STD-129 - Marking for Shipment and Stor
4、age FSC 5610 - /I I . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-20078C 56 777770b 0213115 2 1 MIL -6-2009 8C . (Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement
5、functions should be obtained from the procuring activity or as directed by the contracting officer .) 2.2 -. The following document fonns a part of this specification to the extent 8pecified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids shall apply. AMERICAH
6、SOCZETY FOR TESTING AND MATERIALS Method C266 - Teat for Time of Setting of Hydraulic Cement by Gillmore Needles (Application for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pa., 19103.) 3. REQUIREWNTS 3.1 mterial. The reaterial shall
7、 be a high-quality calcined gypsum meeting the requirements hereinafter specified. 3.2 Fineness. All the material ohall pass a No. 20 U. S. standard test sieve, while not less than 95 percent shally,pass a No. 100 sieve, when tested as specified in 4.5.1. 3.3. Set- ta. 3.3.1 TVDC I. The calcined gyp
8、sum shall set in not les8 than 20 minutes nor more than 25 minutes from the initial time of addition of water to the material. The setting tirne shall be determined as specified in 4.5.2. 3.3.2 TvDe 14. The calcined gypsum shall set in not less than 20 minutes nor aiore than two hours. 3.4 Shrtwe an
9、d em- o . The calcined gypsum shall not shrink The gypeum more than 0.10 percent when tested as,-specified in 4.5.3. shall not expand when so tested. 3.5 mession str-. 3.5.1 TvpeJ,. The average compfession strength of the dry set calcined gypaum shall be not less than 3,400 psi when tested a8 specif
10、ied in 4.5.4. The compression strength of any one of the iridividual test specimen8 shall be not less than 2,900 psi. 3.5.2 TvDe 11. shall not be lesa The conpression strength of type II calcined gypsura ; than 4,000 pounds psi. a Provided by IHSNot for ResaleNo reproduction or networking permitted
11、without license from IHS-,-,-MPL-G-2009 8C 3.6 Wm. The calcined gypsum ehe11 be a dry, powdered material, smooth in texture, and free of lumps and extraneous matter. shall be proceesed in accordance with high-grade commercial practice. The material 4. QUALITY ASSITBANCIS PBoVISIOS 4.1 RSDOO utv for
12、mDecth . Unless otherwise specified in the Except as otherwise contract or purchase order, the eupplier.is responsible for the perforeence of all inspection requirements as specified herein. specified in the contract or order, the supplier may use hie OWLI or any other facilities suitable for the pe
13、rformance of the inspection requirexitents specified herein, unless disapproved by the Cotrerusent. The Government re8erves the right to perform any of the nepections ret forth in the specification where such inspections are deemed necessary to aasure supplies and services conform to prerrcribcd req
14、uircwnts. produced under like conditions in one unchanged process by ooc manu- facturer and presented for: acceptance at one time. 4.2 La. A lot of calcined gypsum shell be of uniform composition, 4.3 SaaiDling. 4.3.1 Samlioe for examin at iog . A random raple of shipping containers shall be oelecte
15、d for examination of the gypsum and for the preparation for delivery in accordance with level 1 of MXL-STD-105. 4.3.2 Samm tw . Five containers shall be taken at random from the lot. A composite 2-pound sample rhall be prepared by rcIMtling equal portions of material from each relected container, an
16、d mixing th- thoroughly. metal container, labeled to show the naam of the material, lot number, lot size, contract or order number, and name of the contractor. acceptance tests shall be performad on material drawn from the composite sap le. The composite oample rrhall be placed in a tkghtlp eerled A
17、ll 4.4 ExwnatiQp. 4.4.1 m. Sample Uslit6 selected in accordance with 4.3.1 shall be examined for visual defects in the calcined gypsum and at the acceptable quality level shown in table I. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-2009 8C
18、 Table I. Examination of gypsum, calcined AQL Classification Method of mteria 1 Percent of de ec te Defects exooa tien. Calcined gypoum 2.5 Major 101 Not dry Viau1 and tactile (See 3.6 and Major 102 Not powdered Vfoual and tactile -=-.-4-4_. 12-.- _ -Bkjor71L Not sntooth Visual and tactile ia textur
19、e Major 104 Not free from Virual Major 105 Contains ex- Visual lumps trancou8 wtter 4.4.2 Packagim. u ackinn and naarkiqg. Sample units aelected in accord- ancc with 4.3.1 shall be examined for the defecto ad at the acceptable quality level shown in table II. 4 Provided by IHSNot for ResaleNo reprod
20、uction or networking permitted without license from IHS-,-,-MIL-G-20078C N Q) h( Q) d a O rn N CI o B M cl rl i U 6 a w O w H o d 8 rLtrr O000 %nG M El 4 n4 a Co h U a K or -v( o- or oi OX %.! h ur O Ltw O0 aa 9 U Q U Q N . $5 angle between adjacent interior faces and between interior faces and to a
21、nd bottom planes of the mold shall be 90 f 0.05 deg. measured at points slightly removed from the intersection of the faces. The mld shall have not more than 3 cube . Interior faces shall be plane 4.5.4.3 procedur e. Allow the material in the moide to set for I hour, remove the set blocks from the m
22、olde, and dry them completely in an atmosphere conditioned to a temperature of 70 to 80F and a relative humidity of 30 to SO percent, as specified in 4.5.3. of the blocks so that each block may be placed in the compression testing machine with its marked side up. the compression load at the rate of
23、20,000 f 2,000 pounds per minute, until the block is crushed. Record the load required to crueh each of the 5 blocks. Calculate the average compression strength in tem8 of pounds per square inch. strengths are not as indicated in 3.5. Mark the top aide Place a block in the nachine and apply The mate
24、rials shall be rejected if the compression 5. PREPARATION FOR DELIVERY 5.1 Packarring . 5.1.1 &eve1 A. Packaging shall be level A or C as specified (see 6.2). Calcined gypsum irhall be packaged 1 pound net weight in metal containers of suitable size conforming to type V, claas 2 of PPP-C-96, or 100
25、pound shipping paper sacke conforming to type XI, IV, or V as specified, of construction number 12X, of -S-48. 5.1.2 Level 6. Unless athemiss specified, calcined gypsum shall be packaged in metal containero or sacks 88 opecified in 5.1.1, except as follows: The exterior coating shall not be required
26、 %of the can of PPP-C-96, and the construction number LOX bag of -S-48 shall be uaed (see 6.2). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-20098C 5.2 Packing. 5.2.1 Level A. Containers as specified in 5.1.1 shall be packed in Packing shall
27、 be level A or C as specified (see 6.2) accordance with the overseas shipment requirements of the appendix to PPP-C-96. Paper sacks as specified in 5.1.1 shall be packed in accordance with the overseas shipment requirements of table XII of UU-S-48. 5.2.2 Level C. Either 50 pounds or 100 pounds, as s
28、pecified (see 6.2), of calcined gypsum shall be packed in a paper shipping sack conforming to - -I- sfyle-El-y-t , ype optlonal y const-rucriorrmbeni 4X-or- IOX, -respectively-, Of UU-S-48. 5.3 Marking. procuring activity (see 6.2), all containers shall be marked in accordance with MIL-STD- 129. In
29、addition to any special marking specified by the 6. NOTES 6.1 Intended use. Calcined gypsum is used in the manufacture and assembly of level vials for fire control equipment, also as an ingredient in fillers used in inert ammunition. 6.2 Ordering data. Procurement documents should specify the follow
30、ing: (a) Title, number and date of this specification. (b) (c) Unit quantities required. Selection of applicable levels of packaging and packing. 6.3 A dish, such as Catalog No. 4357, A. H. Thomas Co., Philadelphia, Pa., has been found to be a suitable container for holding the calcined gypsum in ma
31、king the setting time determination (see 4.5.2). i 6.4 Supersession. This specification Spersedes MIL-G-20098B dated 31 July 1963 and PA-PD-290(Rev. i), dated 21 October 1955. Type I is applicable where previous issues of MIL-G-20098 are referenced. Type II replaces PA-PD-290. Custodian: Amy - MU Air Force - 84. . Review activities: Amy - MU, MD Ais Force - 84, 85 User activities: Army - MI, EL Preparing activity: Amy - Mu Project No, 5610-0056 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
