Correlations Among Various Self-Consolidating Concrete Workability Responses

摘要

Self-consolidating concrete (SCC) mixtures designated for precast, prestressed applications should be highlyworkable to flow easily through restricted spacing and completely encapsulate reinforcements without any mechanicalvibration. Key workability characteristics of SCC can be described in terms of filling ability, passing ability, andresistance to segregation. These properties are typically characterized by data that relate to specific testing methods. Ingeneral, these methods include the components required for evaluating simultaneously filling ability, passing ability, andresistance to segregation, since these properties are rather interrelated. In this investigation, 33 SCC mixtures made withvarious mixture proportioning parameters, including maximum size and type of aggregate, type and content of binder, andw/cm were evaluated. The mixtures were prepared using crushed aggregate and gravel of three different nominal sizes,w/cm of 0.33 and 0.38, and three binder compositions: Type MS cement, Type HE cement with 30% of slag replacement,and Type HE cement with 20% of Class F fly ash. Comparisons and correlations among various test results used inevaluating the workability responses obtained for these mixtures are established. This is done to highlight advantages andlimitations of the various test methods that can be used to assess workability of SCC designated for prestressedapplications. Appropriate combinations of test methods that can be used to assess workability of SCC at the precast plantare recommended, and ranges of acceptance of the various test methods are established.