Excerpt from Survey of Concrete Transport Properties and Their Measurement Concrete is one of the most widely used building materials in the construction of the nation's infrastructure including highways, bridges, water supply and sewage systems, harbors, locks, dams, tunnels and buildings. Over 500 million tons of concrete are produced in the United States each year of which a significant fraction is used for repair and rehabilitation rather than new construction. The service life and utility of concrete strongly depends on its transport properties li.e. Permeability, sorptivity and chloride permeability). For example, concrete is a building material with potential use for long term storage of hazardous substances such as nuclear and toxic wastes. In such applications it is essential that concrete have a very low permeability. On the other hand, it has been suggested that very low permeability high performance-concrete (hpc) may have serious deficiencies as a building material due to possible spalling when subject to high temperatures resulting from fires. Although concrete is commonly thought of as a static or unchanging material, it is, over the typical service life of a structure, a dynamical changing composite material which may undergo considerable degradation. The ingress of potentially deleterious materials such as chlorides, sulfates and water by diffusion and capillary transport can lead to the corrosion of steel reinforcement or a reduction of strength due to cracking by frost or sulfate attack. Clearly, a variety of transport mechanisms play an important role in the degradation of concrete and must be better understood to mitigate such processes. 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.