IX, A, 2 Reihling: Natural Cement versus Brick 173 



Enough work has been done to prove the feasibility of the 

 commercial manufacture of natural cement at Iwahig and to 

 show that the product will meet the requirements of many- 

 kinds of concrete construction work. Natural cement can be 

 used to advantage mixed with Portland cement. A mixture 

 containing 9 parts of natural and 1 part of Portland cement 

 will gain strength more rapidly than natural cement and may 

 be employed where early removal of the forms is desirable. 

 It is probable that by further study the raw materials could 

 be utilized to produce much better natural cements than those 

 described in the preceding pages, and a thorough investigation 

 should be made before a cement plant is installed. 



