Structures designed with congested reinforcing steel often require Self-Consolidating Concrete (SCC) mix designs to assure structures free of voids and honeycombing. The J-Ring test, in conjunction with the Slump-Flow test, is one way to determine the passing ability of SCC, defined as the ability of the concrete to flow under its own weight to completely fill all spaces within the formwork.
Depending upon the procedure selected, a modified slump cone is positioned either inverted or upright in the middle of the J-Ring and filled with concrete in a single lift. The cone is then lifted straight up and the diameter of the resulting circular flow of concrete is measured. A similar test is then run without the J-Ring in place and the difference in the flow diameters is recorded as the passing ability. Additional measurements or visual classifications may also be determined at the conclusion of the test.
Gilson offers this equipment as a set or as individual components. The complete HM-55 set includes the J-Ring assembly, Modified Slump Cone, high-density polyethylene Strike-Off Bar and a plastic Base Plate with convenient cut-out carrying handles.
The Base Plate is inscribed with concentric circles for use when performing the optional relative viscosity procedure described in ASTM C1611.