Properties of Fresh Concrete
Workability
- Definition: The ease with which concrete can be mixed, placed, and finished.
- Factors Influencing Workability:
Consistency
- Definition: A measure of the fluidity or wetness of concrete.
- Testing: Slump test is commonly used to assess consistency.
Plasticity
- Definition: The ability of fresh concrete to flow and be molded without segregation.
Cohesiveness
- Definition: The ability of concrete to hold all ingredients together without separation or bleeding.
Setting Time
- Initial Setting: Time taken for concrete to start hardening.
- Final Setting: Time taken for concrete to completely harden.
- Factors Affecting Setting Time:
- Ambient temperature
- Cement type
- Mixing water
Temperature Effects
- Higher Temperatures: Accelerate setting and can result in quick loss of workability.
- Lower Temperatures: Slow down setting and can delay construction schedules.
Compaction
- Importance: Ensures removal of entrapped air and achieves the desired density.
- Method: Can be achieved using mechanical vibrations.
These notes cover the critical properties that define the behavior and quality of fresh concrete. Understanding these properties is essential for ensuring successful concrete placement and durability.
0 Comments