ABSTRACT
This chapter deals with durability indicators, which are a set of tools to quantify and control concrete durability in construction. It reviews durability indicators, which can encompass physical, mechanical, chemical, and electrochemical properties of concrete. Durability indicators or indexes comprise quantifiable chemical, physical, or engineering parameters that characterize the concrete. They must be sensitive to materials, processing, and environmental factors such as binder type and presence of supplementary cementing materials (SCMs), water/binder ratio, other mix constituents, placing and compaction, type and degree of curing, and so on. Calcium hydroxide content is a measure of the "alkalinity" of the concrete matrix. Diffusivity and conductivity refer to the transport of ionic and molecular species through concrete due to a concentration difference or a potential difference, respectively. Electrical resistivity is an important physic electrochemical property of concrete that affects a variety of applications. The rapid chloride permeability test (RCPT) measures the charge passed through a concrete cylinder under a 60-V potential difference.
