Performance-Based Specifications of Self-Consolidating Concrete Used in Structural Applications

Abstract

Proper selection of test methods and workability specifications are key concerns in the optimization and control testing of self-consolidating concrete (SCC). An experimental program was carried out to evaluate the suitability of various test methods for workability assessment and to propose performance specifications of such concrete used in structural applications. Various workability characteristics were determined for approximately 70 SCC mixtures made with water-cementitious material ratios (w/cm) of 0.35 and 0.42. Workability responses included the slump flow, J-Ring, V-funnel flow time, L-box, filling capacity, and surface settlement tests. Comparisons of various test methods indicate that the L-box blocking ratio (h 2 /h 1 ) and the J-Ring flow diameter can be related to filling capacity values determined using the caisson test. It is recommended that SCC used in structural applications should have slump flow values of 620 to 720 mm. To ensure proper filling capacity greater than 80%, such concrete should have high passing ability that corresponds to L-box blocking ratio (h 2 /h 1 ) ≥ 2 0.7, J-Ring flow of 600 to 700 mm, slump flow minus J-Ring flow diameter ≤ 50 mm, or V-funnel flow time ≤ 8 seconds. Such SCC should have a settlement rate of 0.16%/h at 30 minutes, corresponding to 0.5% maximum settlement.