Correct Answer - Option 4 : Reduces strength
Explanation:
If oil is present in the mixing of concrete then it will reduce the strength
Air Entraining Agents:
- Natural wood resins, Animal and vegetable fats, and oils such as tallow, olive oil and their fatty acids such as stearic and oleic acids.
- Various wetting agents such as alkali salts or sulfonated organic compounds
- Water soluble soaps of resins acid
- Miscellaneous materials such as sodium salts of petroleum sulphonic acids, hydrogen peroxide and aluminium powder,
Air entrainment will affect directly the following three properties of concrete
- Increased resistance to freezing and thawing
- Improvement in workability
- Reduction in strength
Vegetable oil interaction with Concrete:
Vegetable oil when spilled or splattered onto a concrete surface will absorb into it. But concrete is porous by nature and absorbs oily and wet stains.
When the vegetable oil is left on the surface and absorbed into the cement, it causes discoloration and acts as a stain magnet, attracting more dirt and debris.
