Fred T. Hodgson · Frederick J. Drake and Co. · leaf 501
HOW TO USE THEM 497 … Pig. 44. 498 CEMENTS AND CONCRETES show that a 6-inch thickness of 1-2-4 concrete properlymade is waterproof up to about 50 pounds to the squareinch. This concrete is frequently used for facingdams. 1-3-6 is the proportion generally used for theinterior of dams and large structures. It is…