Excerpt from Concrete Strength During Construction Three types of concrete specimens were used. For the compressive and splitting tests, conventional 6 x 12 in (15 x 30 cm) cylinders were cast in waxed cardboard molds. For the nde tests, unreinforced 3 ft x 5 ft x 5 in thick m x m x 140 mm) slabs were cast in oiled wood forms. The pull-out specimens for the relative bond - strength tests consisted of a 48 in m) long No. 6 in or 19 mm) deformed reinforcing bar ksi, or mpa yield) cast in a 6 x 8 in (15 x 20 cm) waxed cardboard cylinder mold. Figure 1 shows the pull-out specimen and mold. The specimens were made so that the bar was bonded to the concrete for a length of 6 inches cm) in all specimens. The pull-out molds were set up for casting in gang racks holding 6 specimens each. The racks were designed to rigidly hold each bar in a Vertical position during the casting operation and during curing. The metal bottom of each cylinder mold had a hole drilled in it so that the bottom end of the bar would extend into a hole in the plywood base of the rack. A plastic furniture tip over the end of the bar sealed the hole in'the bottom of the mold and protected the end of the bar. The concrete cylinder of each pull-out specimen was reinforced with a in cm) diameter cage made of 2 in x 2 in (5 cm x 5 cm) welded steel wire mesh of 16 gage in or mm). About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.