Astm tests for self consolidating concrete, video on this topic
A higher T20 T50 value indicates a more viscous mix which is more appropriate for concrete in applications with congested reinforcement or in deep sections.
When the cone is lifted, the SCC spreads out like pancake batter. The primary test used in the field for SCC is slump flow, although there are other fields tests currently in use.
Thanks to our Website Sponsors Testing Several test procedures have been successfully employed to measure the plastic properties of Self-Consolidating Concrete. The slump cone is completely filled without consolidation, the cone lifted, and the spread of the concrete measured.
J-ring—The J-Ring is a measure of the concrete's passing ability—how easily it flows through obstructions and reinforcing.
A lower T20 T50 value may be appropriate for concrete that has to travel long horizontal distances without much obstruction. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard.
The spread can range from 18 to 32 inches to mm. A VSI of 0 or 1 indicates a stable mix, while a 2 or 3 is unstable.
Therefore, this test method is considered applicable to self-consolidating concrete having coarse aggregate up to 25 mm [1 in.
The U- box, L-box and J-ring tests measure the passing ability of concrete in congested reinforcement.
The U-Box and L-Box tests are used for product development or prequalification and involve filling concrete on one side of the box and then opening a gate to allow the concrete to flow through the opening containing rebar. Another test being standardized is a column test, which measures the coarse aggregate content of concrete at different heights in a placed columnar specimen as an indication of stability or resistance to segregation.
A difference greater than 2 inches indicates poor passing ability.
Appendix X1 provides non-mandatory visual rating criteria that may be used to classify the ability of a self-consolidating concrete mixture to resist segregation stability. The slump flow test is run both with and without the J-Ring in place and the passing ability is the difference in slump flow.