CONTENTS. 



Department Bulletin No. 1076,— Biology op the Lotus Borer (Pyrausta 



genitalis Grote): p 



Introductory 2. 



Systematic history .'.'.'.'. 2 



Studies at Knoxville, Tenn '.'...'. 2 



Life cycle '/'[ 4 



Feeding habits on the leaves ] 5 



Feeding habits on the pods g 



Pupation of the first generation 7 



Pupation of the second generation 7 



Habits of the moths 3 



The egg ,[[[[ 9 



Food plants 10 



Enemies 10 



Literature cited 13 



Department Bulletin No. 1077. — Portland Cement Concrete Roads: 



Introduction 1 



Materials used in concrete roads 3 



Cement 3 



Fine aggregate 3 



Coarse aggregate 4 



Water 5 



Reinforcement 6 



Proportioning 6 



Quantities of materials required 10 



Design of concrete roads 10 



Width of pavement 11 



Thickness of pavement 12 



Crown of pavement 14 



Superelevation of curves 15 



Widening on curves 16 



Joints 20 



Steel reinforcement 23 



Shoulders and ditches 24 



Curbs and gutters 25 



Bituminous surface treatment 25 



The cross section 27 



Construction. . .«. .- 27 



Grading 27 



Drainage 27 



Preparation of the subgrade 29 



Forms 30 



Handling and hauling materials 31 



Mixing and placing .' 40 



Finishing the surface 42 



Protecting and curing the concrete 46 



Placing concrete in freezing weather 47 



Organization and equipment 47 



Capital required - ^^ 



Cost of concrete pavements ^^ 



Maintenance ^^ 



Resurfacing old concrete pavements ^^ 



Appendix '. "J 



A. Quantities of materials required -.--•:•■ 



B. Tables for determining the size of pump required for delivering 



water ^^ 



C. Cost of Federal-aid concrete pavements "4 



3 



