3.1.4. J-Ring Test

Figure 13 shows the J-Ring test results expressed to the nearest 10 mm for all mixtures. In this experimental work, the J-ring test was used to assess SCC passing ability [60,74]. This is crucial to be sure that SCC can flow through spaces between and around congested reinforcement, through tight openings, and around any other obstructions that might prevent SCC from flowing during the casting process without segregation, blocking, or leaving voids. As can be seen from the figure, the spread flow ability of OPC-SCC is 600 mm, whereas all developed sustainable high-strength SCCs showed a higher ability to flow and spread within the casting process.

The results showed that there was an increase in the flow spread of concrete produced with binder containing FA and MS. The increase was 15%, 17%, and 17% for SCC produced by replacing OPC with 20.43%, 29.5%, and 38.74% of the FA + MS system, respectively. Replacing OPC with high levels of GGBS and MS also showed an increase in the spread flow ability. The results registered 12%, 15%, and 10% increases in the flow spread for mixtures produced with 38.74%, 52.6%, and 71.16% GGBS + MS, respectively. Generally, the test depicted the capability of SCC produced with high levels of replacement to fill the formwork without segregation or blocking even with congested reinforcement and the possibility of full compaction based on its weight.

**Figure 13.** J-ring flow mm of SCC mixture.
