Document 6R59qyJZo5myy8wp51nNpwmn9

Johns-Manville Research Center Ki/^ Report No. 431-384 Dote June 29, I960 Title: ARMSTRONG JU25, JM-23 and JM-26 INSULATING FIRE BRICK - HUXERIIES Requested by: Sales Service Request IK-272 r> c* ^ 11 / -I V t D G- B. BROWN summary jul 1 4 1960 A 75-brick sample of Armstrong A-25 insulating fire brick from General Refractories Company was tested far comparison with JM-23 and JK-26 insulating fire brick. ' Since A-25 insulating fire brick are manufactured by Armstrong Cork Company far sale by General Refractories Company, the brand name on the specimens was "GREFCO GR-25. * JM-26 specimens from laboratory stock were used for determination of shrinkage at 250QF. Samples of JM-23 and JM-26 submitted by totality Control far annual tests were used for determination of other properties. A comparison of properties was needed to promote the sale of J-M insulating fire brick to lindberg Engineering Company. The results were: Density, pcf Modulus of Rupture, psi Cold Crushing Strength, psi Linear Change, % - 23OOF 250QF 260QF A-25 39.5 175 394 0.0 -4.2 -- JM-23 44.5 191 240 -0.1 -6.1 -- JM-26 49.9 153 255 _ -0.6 -0.8 Judging from the structure and the strength, it was concluded that cork had been used far the burn-out in the manufacture of A-25 insulating fire brick. The objectives of Sales Service Request IK-272 were attained. Contents: Summary, Appendix I - Table, Appendix II - fhotographs. Reported by S. E. Uooley f cc: C. F. Rassweiler, GH (+S) Attn: H. S. Allen J. E. Begert, GH (S) J. B. Jobe, DH (S) M. U. Burleson, DH (S) U. D. Gechea, DH (S) N. J. Kent, DH S. C. Lindstrom, DH Notebook Ho. 1819, pp 109-116 J. A. McKinney S. E. Uooley (C) File: U. M. MacAlpine Library (5) C File 43111