Test Methods for Concrete Durability

Abstract

Concrete is considered as one of the fundamental component in the field of construction. Due to this purpose, it is very important to check the durability of concrete that has to be used. In this research, various testing methods for checking the durability of concrete are discussed. There are several methods designed that can effectively analyze that either concrete are durable for construction or not. It is mostly assumed that durability of concrete depends on its transport properties such as permeability, diffusion and absorption. Like a first line protection is offered by the concrete cover against the entrance of several harmful elements into the concrete, similarly a measure of it transport properties play essential role in accessing its durable performance in the given situation. By using array of electrical sensors that are present in the cover concrete, the rate of ingress of the deleterious substances could be monitored in new structures. For testing concrete durability the apparatus that are used include permeability apparatuses, viz. Autoclam Permeability System and Permit Ion Migration Test. These are used for measuring water absorption and Permit Ion Migration Test as well as for determining the ionic diffusion. In order to carry out the test, these instruments can be mounted on the concrete surface. These are the two effective testing methods for concrete durability. It is observed that in most concrete, quality decreases slowly with the passage of time not instantly. The rate of change of performance is changed by or the performance level is altered by intermittent maintenance and deterioration with time. Due to this, a continuous monitoring of the structure condition is necessarily required. This shows that the main need of testing and monitoring strategy is to measure the structure of the building on the completion of the construction. That can further be checked.

Table of Contents

Abstract3

Introduction5

Discussion5

Testing Variation6

Durability Principles6

Test in Current Practices7

Core Testing7

Ingress of moisture tests8

Absorption tests8

Permeability tests10

Diffusion tests12

Water Absorption Test12

Importance of Concrete Durability Testing16

References21

Introduction

Concrete is the most commonly used construction material internationally. It has been observed that mechanisms of deterioration are mostly because of the transport and micro structure properties of the concrete cover. It is because the transport properties of the concrete cover influence the environmental penetrations that cause damage. However, it is important to test concrete destructively at the surface for accessing the quality and performance at the time of construction (Goodspeed, Vanikar, and Cook, 2009). It is considered that the durability of reinforced concrete structure is much dependent on their resistance to:

Deterioration of freeze-thaw

Salts in pores crystallization

Reinforcement corrosion as a result of leaching, chloride ingress and carbonation.

Sulphate attack

Alkali attack

Acid attack

Reaction in alkali-silica

Cracking in both the hardened and pre-hardening states.

Abrasion

And fire damage

Discussion

When there is the requirement of testing concrete durability, it is highly recommended that engineers should not completely depend on specifying maximum water-cement ratio, minimum compressive strength, minimum air entrainment and cementitious content (Spence, 2010). In order to quantify the durability of concrete, there are much better and effective ways provided. Two main performance characteristics of ...