Permeability of Concrete - A "silent killer"

J.Burman Roy. Visiting Faculty in School of Planning and Architecture.
Managing Director, Design DeigratiaTM New Delhi

Introduction

Excellent long-term performance of concrete structures is associated with both concrete strength and durability properties, e.g., Permeability which is a governing property to estimate durability of a concrete structure. Many laboratory tests exist for measuring this property. In this article, a brief discussion about water and air permeability is presented followed by various experimental methods and laboratory equipment. In the end, analysis of the works of various researchers is included and there results are compiled to arrive at conclusion w.r.t. my point of view.

Concrete Durability

A concrete structure is considered to be of adequate durability if it performs in accordance with its intended level of functionality and serviceability over an expected or predicted life cycle. Durable concrete must have the ability to withstand the potentially deteriorative conditions to which it can reasonably be expected to be exposed.

In terms of deterioration of concrete due to physical or chemical causes, the mobility of fluids or gases through the concrete are nearly always involved. The overall susceptibility, or penetrability of a concrete structure, especially when compounded by additional environmental or exposure challenges, is the key to its ultimate serviceability and durability. Low porosity / permeability / penetrability of concrete to moisture and gas is the first line of defense against: frost damage, acid attack, sulfate attack, corrosion of steel embedment and reinforcements, carbonation, alkali-aggregate reaction, and efflorescence to name a few of the most prominent concrete ailments.