29 



varies from 10 to 15, the latter being used In 

 -c 

 calculations. 



ncsults of Prof. Hatt's Experiments to Determine 

 of Concrete. 



The adhesion of concrete to the steel can be taken at 

 300 Ib. per sq. in. Prof. Hatt made the following de- 

 terminations: 



Results of Prof. Hatfs Adhesion Tests of Concrete 



and Iron. 



