CHAPTER I

.--METHODS AND COST OF SELECTING AND PREPARING

MATERIALS FOR CONCRETE. 1

~Cement:~ Portland Cement--Natural Cement--Slag Cement--Size and Weight of Barrels of Cement--Specifications and Testing. ~Sand:~ Properties of Good Sand--Cost of Sand--Washing Sand; Washing with Hose; Washing with Sand Ejectors; Washing with Tank Washers. ~Aggregates:~ Broken Stone--Gravel--Slag and Cinders--Balanced Aggregate--Size of Aggregate--Cost of Aggregate--Screened and Crusher Run Stone for Concrete--Quarrying and Crushing Stone--Screening and Washing Gravel.

##