Test methods on SCC (Self Compacting Concrete)
The methods presented here are devised specifically for SCC. Existing rheological test procedure have not considered here, though the relationship between the results of these tests & the rheological characteristics of the concrete is likely to figure highly in future work, including standardization work. In considering these tests there are number of points which should be taken into account:
- There is no clear relation between test results & performance on site.
- There is little precise data, therefore no clear guidance on compliance limits.
A concrete mix can only be classified as SCC if the requirements for all the following three workability properties are fulfilled.
1. Filling ability,
2. Passing ability, &
3. Segregation resistance.
Filling ability: It is the ability of SCC to flow into all spaces within the formwork under its own weight. Tests, such as slump flow, V-funnel etc, are used to determine the filling ability of fresh concrete.
Passing ability: It is the ability of SCC to flow through tight openings, such as spaces between steel reinforcing bars, under its own weight. Passing ability can be determined by using U-box, L-box, Fill-box, and J-ring test methods.
Segregation resistance: The SCC must meet the filling ability and passing ability with uniform composition throughout the process of transport and placing.
Test methods to determine workability of SCC are:
3. L Box Test
4. U Box Test