34 The Philippine Journal of Science 



SUMMARY 



Three mixtures of Meycauayan tuff with hydrated lime were 

 made and subjected to a number of physical tests. Mix A con- 

 tained 90 per cent tuff; B, 75 per cent; and C, 50 per cent. 

 The following conclusions are based on the results obtained: 



1. A mixture of Meycauayan tuff and hydrated lime possesses 

 hydraulic properties. It is not suitable for construction per- 

 manently exposed to the air, but develops considerable strength 

 in water. 



2. Increasing percentage of lime is accompanied by a retar- 

 dation of set and a decrease in the specific gravity. 



3. The tensile strength is influenced by the fineness of the 

 material. A coarser grind shows lower tensile strength, but 

 the specimens are less liable to crack when stored in air. 



4. In general, mix B gave the most satisfactory results. 



