IS 13642:1993 is the Indian Standard (BIS) for recommendations for selection of repair materials for concrete structures. This standard provides guidelines for the diagnosis of damage in concrete structures and the selection of appropriate repair materials. It details the desirable properties for repair materials, such as bond strength, compatibility, and durability, and offers a framework for choosing the correct material and system for various types of defects.
Provides recommendations for the selection of appropriate repair materials for different types of concrete structures and defects.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Bond Strength (Pull-off Test) | Recommends it to be adequate, with failure preferably in the substrate concrete, not the bond line. No absolute value specified. | ≥ 2.0 N/mm² for Class R4 structural repair mortar. | EN 1504-3 |
| Compressive Strength (28 days) | Should be compatible with and generally slightly higher than the substrate concrete. | Defined by class: R4 > 45 N/mm²; R3 > 25 N/mm²; R2 > 15 N/mm². | EN 1504-3 |
| Chloride Ion Content | Advises limiting chlorides to prevent corrosion, typically by reference to standards for concrete constituents. | ≤ 0.05% by mass of dry mortar. | EN 1504-3 |
| Capillary Absorption | Recommends low water absorption and permeability to protect reinforcement, but no quantitative limit is given. | ≤ 0.5 kg·m⁻²·h⁻⁰.⁵ | EN 1504-3 |
| Modulus of Elasticity | Recommends the modulus to be equal to or lower than the parent concrete to avoid stress concentrations. | Required to be a declared value by the manufacturer; specific requirements for some repair principles (e.g., must be > 20 GPa for R4 mortars). | EN 1504-3 |
| Restrained Shrinkage/Expansion | Stresses the importance of dimensional stability and compatibility to prevent cracking and debonding. | After cycling, the repair mortar must show no cracking, delamination, or debonding, and retain a pull-off strength ≥ 1.5 N/mm² (for R3/R4 mortars). | EN 1504-3 |