Q: I am project manager for a concrete contractor. We have our first large self-consolidating concrete (SCC) project coming up soon, so I want to ensure that we get this right. The engineer performed the required test mixes to confirm slump, flow, spread, and compressive strength performance. The mix from the concrete producer passed with flying colors. Even so, the engineer is still nervous about the placement. What else should we do to ensure that the job goes smoothly?
A: Preparing for a new SCC project requires careful development of a conservative mix design along with a thorough material quality control program. You must ensure you are producing robust SCC mixes—meaning the mix will retain its properties even with minor variations in temperature, water content, and mix ingredients. On any given day a producer can batch acceptable SCC. The trick is to maintain this level of performance throughout an entire project. If you apply meticulous quality control then your project should be successful.
There's a new learning resource that may help you and your team prepare for this project. Diane Hughes, from Hughes Concrete eduTraining, will lead the “SCC for Ready Mix Concrete Practitioners” course through the World Center for Concrete Technology, Alpena, Mich.
This eight-week online course explores the topic of SCC from a ready-mixed concrete perspective. Hughes will cover the fundamentals of SCC rheology, fresh-concrete properties, test methods, and mix proportioning. Detailed guidelines on laboratory test mix protocols and production, as well as placement checklists are provided.
Students will benefit from understanding the reasons why some SCC mixes are successful, while others are not; how new SCC ASTM test methods are applied and interpreted; and why step-by-step attention to detail pays off at the plant and at the jobsite. The course is geared for contractors, testing laboratories, engineers, architects, and concrete producers. The next class begins on Aug. 24. You can learn more by visiting the WCCT Web site at www.wcct.net.