TABLE OF CONTENTS All man-made and natural materials are susceptible to deterioration. This topic is so broad that it is not possible to cover every type of geotechnical and foundation element susceptible to deterioration. Instead, this chapter will discuss four of the more common types of deterioration: sulfate attack of concrete, pavement distress, frost-related damage, and damage caused by tree roots.
In terms of deterioration, the National Science Foundation (NSF, 1992) states:
The infrastructure deteriorates with time, due to aging of the materials, excessive use, overloading, climatic conditions, lack of sufficient maintenance, and difficulties encountered in proper inspection methods. All of these factors contribute to the obsolescence of the structural system as a whole. As a result, repair, retrofit, rehabilitation, and replacement become necessary actions to be taken to insure the safety of the public.
Sulfate attack of concrete is defined as a chemical and/or physical reaction between sul-fates (usually in the soil or groundwater) and concrete or mortar, primarily with hydrated calcium aluminate in the cement-paste matrix, often causing deterioration (ACI, 1990). Sulfate attack of concrete occurs throughout the world, especially in arid areas, such as the southwestern United States. In arid regions, the salts are drawn up into the concrete and then deposited on the concrete surface as the groundwater evaporates, as shown in Figs. 13.1 to 13.3. Sulfate attack of concrete can cause a physical loss of concrete (Fig. 13.4) or the unusual cracking and discoloration of concrete such as shown in Fig.
