Shrinkage of Full-Scale Girders Cast with Self-Consolidating Concrete

Abstract

Shrinkage can be critical factor for the design of structural members due to the length changes by the time-dependent deformation. In this investigation, two self-consolidating concrete (SCC) and two high-performance concrete (HPC) mixtures with target 56-day compressive strengths of 55 and 69 MPa and having 18-hour release strengths of 34.5 MPa and 43 MPa, respectively, were used to cast four full-scale AASHTO-Type II girders measuring 9.44-m in length. For each strength level, the SCC and HPC mixtures were proportioned with the same water-to-cementitious materials ratio (w/cm) and binder type. The high-range water-reducing admixture (HRWRA) dosage was adjusted to obtain a slump flow of 680 ± 20 mm for the SCC mixtures and a slump of 160 ± 20 mm for the HPC mixtures. The constructability and shrinkage of full-scale girders cast with SCC and HPC mixtures used in precast prestressed girders were investigated and compared. Results of tests on full-scale girders indicated that, SCC placement was successfully carried out by casting the concrete from location at the midspan of the 9.44-m long girders. Both HPC and SCC mixtures developed similar autogenous shrinkage for the mixtures made with the similar w/cm; the two SCC mixtures developed about 20% greater drying shrinkage than the comparable HPC mixtures after 112 days of drying.