What are the main stages of durability evaluation?

Preliminary investigation, Detailed investigation, and Specialized investigation (Clause 5.2).

What NDT is used to check for corrosion activity?

Half-Cell Potentiometry is the primary method to assess the probability of active corrosion in reinforcement (Annex B).

What is the indicative limiting crack width for a structure in a 'severe' environment?

0.1 mm, as per Table 2. However, the significance of any crack depends on its cause, nature, and location.

Does this code provide repair methods?

No, this code focuses on evaluation and diagnosis. Repair methods and materials are covered in other standards like the IS 13430 series.

IS 15974

: 2012

Evaluation of Existing Concrete Structures for Durability and Service Life - Guidelines

CurrentSpecializedGuidelinesBIMStructural Engineering · Demolition, Renovation and Repair of Structures

Archive.org BIS Portal Google

This standard provides guidelines for the systematic evaluation of existing concrete structures to assess their condition and durability. It outlines a methodology for investigation, including diagnostic testing (NDT and destructive), to identify causes of deterioration and to aid in the prediction of remaining service life.

Provides guidelines for evaluating existing concrete structures concerning their durability and service life.

Quick Reference Values

Limiting crack width in 'Very Severe/Extreme' exposure0.1 mm

Limiting crack width in 'Moderate' exposure0.2 mm

pH value for passivation of steel reinforcement> 9.5

Max total chloride content for RCC in severe exposure (by mass of cement)0.20 %

Max total chloride content for PSC in severe exposure (by mass of cement)0.10 %

Practical Notes

This is a 'Guidelines' document, not a prescriptive code; it requires significant engineering judgment for interpretation and application.

The code recommends a phased approach: preliminary investigation, followed by detailed and specialized investigations if required. This prevents unnecessary and costly testing.

Service life prediction models discussed are highly sensitive to the quality of input data from investigations. Results should be interpreted as probabilistic indicators for decision-making, not as absolute certainties.