101 



Ing $3.64 per cu. yd., the cost was reduced to $4.72 per 

 cu. yd. in place. The Buffalo breakwater cost, when built 

 In 36 ft. sections, blocks $7.10 per cu. yd., mass concrete 

 $5.65 per cu. yd. When a concrete steel superstructure 

 was built, the same cost $10.00 a cu. yd. for blocks and 

 $9.40 a cu. yd. for mass concrete. 



ABUTMENT WALLS. 



When about 120 ft. long and containing 590 cu. yd., the 

 concrete in abutment walls can be placed at $5.75 per cu. 

 yd; day labor being $1.50 per day of 10 hours, and cement 

 $2.10 per bbl. 



RETAINING WALLS. 



The excavation of these walls costs about 50c per cu. 

 yd. A natural cement base can be put in at $4.00 per 

 cu. yd. of 1:2:4 mix. The Portland cement concrete at 

 $6.25 per yd. 



LEVEE WALLS. 



Levee walls constructed at Columbus, Ohio, 18 in. thick 

 at the top, 50 in. at the bottom and a maximum height of 

 11% ft., the heart of the wall being made of 1:2^:5 

 (crushed pravel). The face of the wall for a thickness of 

 2 in. was of mortar of 1 cement and 2 sand. 



