Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 edition. Excerpt: ... York building authorities have made fourteen tests on concrete constructions, seven of which proved successful. It seems that in the case of the building that failed to stand the test the concrete was too green and the moisture in the concrete was converted into steam that caused the disintegration. Sidewalks, Pavements and Floors. Foundation. The first step in making concrete sidewalks is the excavation of the ground and preparation of the surface by ramming for the reception of the stone, gravel or cinders. In localities where the frosts are heavy the ground should be excavated to a depth of twelve inches. In milder climates it need not be excavated further than six inches. An average thickness for the sub-foundation is six inches, although if the ground is always dry it need not be more than three. The subfoundation--stone, gravel or cinders--should be well pounded down to assure its being firm. The practice in some localities is to permit cinders to lie for some time in place before operations of laying the walk are commenced. The foundation consists of a layer of concrete topped by one of cement mortar. Proportions. In the making of, walks Portland cement should be used. The proportions for the concrete are about 1:3 and a depth of 3 to 4 inches is required. The stone or gravel should be 1 inch in size. Local conditions may change these proportions, however. The cement mortar for the top dressing should be mixed in the proportion of 1 part cement to 2 parts sand. Measurements. As a guide in excavating a cord stretched between stakes will do, after which the bottom of the trench should be rammed. The next step is the driving of stakes along the sides of the walk with their tops made even with the finished parts of the walk. There should be a...
