The suitability of various non-destructive tests are as follows.

1. Surface hardness test- To estimate the concrete strength using Williams testing pistol and impact hammer.

2. Rebound hammer test- To estimate the strength of concrete and comparative investigations.

3. Ultrasonic pulse velocity test- To determine homogeneity of concrete mass and strength of concrete.

4. Penetration and pullout technique- To determine penetration and pullout resistance of concrete mass and hence to determine concrete strength.

5. Dynamic or vibration test- To evaluate durability and uniformity of concrete and to estimate its strength and elastic properties.

6. Radioactive method-To measure density and thickness of concrete using X and gamma ray

7. Nuclear method- To determine moisture and cement content.

8. Magnetic method- To determine cover of reinforcement in concrete mass.

9. Electrical method- To measure moisture content and thickness of concrete.

10. Acoustic emission techniques- To study the initiation and growth of cracks in concrete.