Title: Durability of Concrete - The Zigzag Course of Progress

Author(s): P.K. Mehta

Publication: Symposium Paper

Volume: 234

Issue:

Appears on pages(s): 1-16

Keywords: concrete; damage; deterioration; durability; holistic; macrocracks; microcracks; microstructure; sustainability

DOI: 10.14359/15925

Date: 3/22/2006

Abstract:
Concrete design and construction practices today are essentially strength-driven. However, due to escalation in the repair and replacement costs of structures and a growing concern about sustainability of the concrete industry, more attention is being paid now to durability issues. An overview of the state of the built infrastructure in the world shows that the current methods for achieving considerable enhancement of durability of concrete structures are proving inadequate, especially with concrete members exposed to severe weather conditions. It seems that inhomogeneities in the microstructure of concrete are responsible for microcracks which, when subjected to tensile stress from weathering and loading effects during the service, grow into macrocracks. When the macrocracks, voids, and microcracks become interlinked there is a sudden increase in the rate of transport of water, carrying harmful ions and gases from the surface into the interior of concrete. This point marks the initiation and progressive deterioration of the material from one or more causes. A three-stage concrete damage process is discussed to show what changes in concrete technology are needed for radical enhancement in the durability of structures to be built in the future.