EMINENTLY HYDRAULIC LIMES: GRAPPIER CEMENTS. 185 



Grappier Cements. 



Grappier cements are made by grinding finely the lumps of unburned 

 and overburned material which remain when a hydraulic lime is slaked. 

 These lumps, as earlier noted, consist partly of lime silicate and partly 

 of unburned limestone. The value of the resulting grappier cement 

 will depend on the proportions in which these two ingredients occur 

 in the lumps. If lime silicate forms most of the lumps, the grappier 

 cement will be a very satisfactory material, approximating to Portland 

 cement in its properties. If most, or even a large part, of the lumps 

 consist of unburned limestone, however, the grappier cement will be 

 practically worthless. 



Lafarge cement, well known on the American market as a "non- 

 staining" cement, is a grappier cement of very satisfactory composition 

 made at Teil, France. 



Composition of grappier cements. 



TABLE 80. 

 ANALYSES OF GRAPPIER CEMENTS. 



1. Typical grappier cement. Le Chatelier, Trans. Amer. Inst. Min, Engrs., vol. 22, p. 19. 



2 Teil grappiers. Analysis by Durand-Claye. Quoted by Spalding, " Hydraulic Cement ", p. 20. 



3. Lafarge cement. C. F. McKenna, analyst, 1897. Sales-agents' circular. 



4. Lafarge cement. Quoted by E. Duryee, Engineering News, vol. 47, p. 23. Jan. 9, 1902. 



5. Malain grappier cement. Quoted by Bonnami, " Fabrication et controle des Chaux Hydrau- 



liques ", p. 54. 



Physical properties of grappier cements. The only data available 

 on the strength, etc., of grappier cements are those contained in the 

 circular issued by the American sales-agents of the Lafarge brand. 

 The tests were conducted in 1897 by Dr. C. F. McKenna. 



The Lafarge cement gave the following results: 



Specific gravity, not ignited. . . 2.6 



ignited 2.7 



Loss on ignition 3 . 83% 



Initial set 4 hours 



Final set 10 hours 



Fineness 99 . 8% through 50-mesh 



" 99. 4% through 100- " 



