The J-ring test is used to assess the passing ability of self-compacting concrete to flow through tight openings including spaces between reinforcing bars and other obstructions without segregation or blocking. A narrow and wide bar spacing test is described. The narrow bar spacing simulates more congested reinforcement.
The J-ring test is an alternative to the L-box test EN 12350-10 although the result is not directly comparable.
The method follows the procedure detailed in EN 12350-8 Slump-flow and t500 time for self-compacting concrete except that, before filling the slump cone with concrete, the J ring is placed concentrically over the cone. The J-ring consists of a ring of evenly spaced vertical, smooth bars.
In addition, the time when the concrete has flowed to a diameter of 500 mm t500 may be measured.
The set consists of –
- 41mm Narrow Ring
- 59mm Wide Ring
- Slump Flow Board
- Slump Cone (feet removed)