Before the pour, have your QC staff practice corrective action processes with mixes that are too flowable/segregating, or not flowable enough (too wet or too dry, in conventional concrete terms). This trial run will give your crew the experience to deal calmly and confidently with job-site realities.
Since adjustment to SCC mixes is new to your team, flowchart the mix adjustment process. Make it step-by-step and specify who is authorized to do what. Provide copies and discuss it in detail at the pre-pour meeting.
Adding water to SCC mixes usually is not recommended. For low-slump flow mixes, corrective actions will typically include adding high-range water reducing admixture. Adding viscosity modifying admixtures and/or holding trucks for an additional period is allowed if the mix is segregating or slump flow is too high.
For any SCC project, both pre-construction and pre-pour meetings are essential. This is especially true if the architect is using SCC to achieve a particular look.
Also read, Why is SCC MIA?Want to Learn More?
Diane Hughes will lead the SCC for Ready Mix Concrete Practitioners course offered by the World Center for Concrete Technology in Alpena, Mich. The 12-week online course provides an overview on how to adopt the proper SCC procedures.
The course will educate contractors, lab personnel, engineers, architects, and producers of current procedures for testing SCC. The next class begins in September. Visit www.wcct.net.