Self-consolidating concrete (SCC) is a high-performance concrete that can flow easily into tight and constricted spaces without segregating and without requiring vibration. The key to creating self-consolidating concrete , also referred to as self-compacting, self-leveling, or self-placing concrete, is a mixture that is fluid, but also stable to prevent segregation.
To achieve the desired flowability a new generation of superplasticizers based on polycarboxylate ethers works best. Developed in the 1990s, they produce better water reduction and slower slump loss than traditional superplasticizers. The required level of fluidity is greatly influenced by the particular application under consideration. Obviously the most congested structural members demand the highest fluidity. However, element shape, desired surface finish, and travel distance can also determine the required fluidity.
Generally, the higher the required flowability of the self-consolidating concrete mix, the higher the amount of fine material needed to produce a stable mixture. However, in some cases, a viscosity-modifying admixture (VMA) can be used instead of, or in combination with, an increased fine content to stabilize the concrete mixture.
Self-consolidating concrete is characterized by its unique fresh concrete properties. Therefore, new test methods are being developed to characterize SCC properties. See table for test methods approved or under consideration at American Society for Testing and Materials (ASTM):
TABLE - SCC Test Methods (ASTM) There are many other accepted test methods for self-consolidating concrete that have not been standardized within ASTM. The following table summarizes some of the more recent or commonly used methods:
TABLE - SCC Test Methods (non-ATSM)
Szecsy, R. and Mohler, N., “Self-Consolidating Concrete,”
Portland Cement Association, Skokie, Illinois, 2009, 24 pages.
Self-Compacting Concrete: Bibliography of Resources (2nd ed.)
PCA Library Bibliography Series No. 6 (LB06.02) Portland Cement Association, c2004 for an extensive list of SCC references.
McGovern, M., “Going with the Flow,” Concrete Technology Today, CT022, Portland Cement Association, Skokie, Illinois, July 2002, pages 1, 2, and 8. Click here http://www.cement.org/tech/pdfs/CT022_scc.pdf to download article.
Interested in Self-Consolidating Grout?
Read Masonry Today, Vol. 14, No. 2, Winter 2004/2005,
Flow with Show: Self-Consolidating Concrete Offers New Opportunities for Architectural Concrete, PCA Page Flow with Show: Self-Consolidating Concrete Offers New Opportunities for Architectural Concrete
ACBM, Self-Consolidating Concrete, RP440, Advanced Cement-Based Materials Center, Evanston, Illinois, 2007, 42, pages.