NACE CIP 2 EXAM. QUESTIONS WITH ANSWERS

Laitance: Weak surface layer of water, rich cement mixture caused by upward movement of water Efflorescence: Condition caused by water passing thru concrete and salts reacting with CO2 to create a fluffy, crystalline surface deposit Reasons to coat concrete: 1. Waterproofing 2. Freeze protection 3. Chem. resistance 4. Decontamination 5. Abrasion protection 6. Color coding 7. Contents protection 8. Improved cleaning 9. Skid resistance 10. Steel Re-enforcement Explain Gunniting: Process of sprayiny or slinging concrete onto a surface as a coating How do ambient conditions and vibration affect poured concrete? 1. Hot weather will accelerate cure and cause voids and low strength surface 2. Vibration can cause heavy aggregate to sink resulting in a weak, sandy surface known a laitance What is the process concrete cures by? Hydration