Excerpt from Fire Resistance of Concrete Columns It was found early in the progress of the work that the gravel concrete columns had a decided tendency to Spall, and that this tendency did not manifest itself at all in the limestone concrete columns. Spalling, by causing the loss of a large part of the protective covering, resulted in the attainment of comparatively high temperatures in the interior of the columns from which it occurred. It was found that there was a much stronger tendency for columns with spiral steel to lose their protective concrete by spalling than for round columns with vertical reinforcement only. Square columns made with siliceous aggregates also spalled freely. No spalling took place in limestone concrete columns of any kind. Since the characteristic tendencies of these two aggregates were shown in much stronger contrast in round columns with h00ping and in square columns than in round columns without h00ping, no round columns without h00ping were included in the latter part of the investigation. With the evidence of the early tests in mind, columns from the following aggregates were added to the program. 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.